| 詞或詞組 | 中文 | 英文解釋中文解釋 |
|---|---|---|
| Safe working load (Unit N) | 安全工作負荷（單位：N） |
The steady or unsteady load against which a component or structure is designed for normal operation. It is lower than that which would cause failure by buckling, fracture, or yielding, so as to accommodate uncertainty, possible fault or accident conditions. 部件或結構設計用于正常運行的穩定或不穩定荷載。該值低于因屈曲、斷裂或屈服而導致失效的值，以適應不確定性、可能的故障或事故條件。 |
| Safety valve (safety-relief valve) | 安全閥（安全泄壓閥） |
A mechanical valve, fitted by law to all pressure vessels (e.g. steam boilers), which opens to prevent the internal pressure exceeding the maximum design value for that vessel. The valve closes again once the pressure reduces to a safe level. 根據法律安裝在所有壓力容器（如蒸汽鍋爐）上的機械閥，其打開以防止內部壓力超過該容器的最大設計值。一旦壓力降至安全水平，閥門將再次關閉。 |
| Salt bath heat treatment | 鹽浴熱處理 |
Heat treatment carried out in a bath of molten salt. 在熔融鹽浴中進行的熱處理。 |
| Salt-velocity meter | 鹽速計 |
A volume flow meter based on detecting the transit time for a small quantity of salt or radioactive isotope in a flow by measuring electrical conductivity or radiation level. 一種體積流量計，通過測量電導率或輻射水平來檢測流量中少量鹽或放射性同位素的渡越時間。 |
| Sample average | 樣本平均值 |
The sum of all the observed values in a sample divided by the sample size. It is a point estimate of the population mean. Also known as arithmetic mean. 樣本中所有觀察值的總和除以樣本大小。它是總體平均值的點估計。也稱為算術平均值。 |
| Sample median | 樣本中間值 |
The middle value when all observed values in a sample are arranged in order of magnitude. If an even number of samples are tested, the average of the two middlemost values is used. It is a point estimate of the population median, or 50% point. 當樣本中的所有觀測值按數量級排列時的中間值。如果測試的樣本數為偶數，則使用兩個中間值的平均值。這是人口中位數的一個點估計值，或50%的點。 |
| Sample percentage | 樣本百分比 |
The percentage of observed values between two stated values of the variable under consideration. It is a point estimate of the percentage of the population between the same two stated values. 所考慮變量的兩個規定值之間的觀測值百分比。它是對相同兩個規定值之間的總體百分比的點估計。 |
| Sample standard deviation (s) | 樣本標準偏差（s） |
The square root of the sample variance. It is a point estimate of the population standard deviation, a measure of the “spread”of the frequency distribution of a population. This value of sprovides a statistic that is used in computing interval estimates and several test statistics. For small sample sizes, s underestimates the population standard deviation. 樣本方差的平方根。它是總體標準偏差的點估計，是總體頻率分布“擴散”的度量。SPR的這個值提供了一個用于計算區間估計和若干測試統計量的統計量。對于小樣本，s低估了總體標準偏差。 |
| Sample variance (s2) | 樣本方差（s2） |
The sum of the squares of the differences between each observed value and the sample average divided by the sample size minus one. It is a point estimate of the population variance. 每個觀測值與樣本平均值之差的平方和除以樣本大小減1。它是總體方差的點估計。 |
| Sampling | 抽樣 |
The process of measuring a series of values of a time-varying quantity. 測量一系列時變量值的過程。 |
| Sampling frequency (Unit Hz) | 采樣頻率（單位Hz） |
(sampling rate) The number of measurement samples per unit time taken from a continuous analogue signal to produce a discrete signal. It is the inverse of the time between successive measurements (sampling interval, sampling period, or sampling time). （采樣率）從連續模擬信號中提取以產生離散信號的每單位時間的測量樣本數。它是連續測量之間時間的倒數（采樣間隔、采樣周期或采樣時間）。 |
| Sawing | 鋸切 |
Sawing is the process of cutting a workpiece with power band saws, hacksaws, and circular saws. Each of these methods is used in cutoff operations (cutting pieces to a required length), although band sawing also provides a method of cutting contours. 鋸切是用帶鋸、鋼鋸和圓鋸切割工件的過程。這些方法中的每一種都用于切割操作（將工件切割到所需長度），盡管帶鋸也提供了一種切割輪廓的方法。 |
| Scale effect | 規模效應 |
The change in behaviour with size of a material, component, or structure. For example, cube-square scaling where one element changes with volume and another with area, as in the range of a projectile or ship, droplet formation, and fracture mechanics. 性能隨材料、部件或結構尺寸的變化。例如，立方體平方比例，其中一個元素隨體積變化，另一個元素因面積變化，如在射彈或飛船的射程、液滴形成和斷裂力學中。 |
| Scale height (Unit m) | 刻度高度（單位：m） |
The altitude H at which the atmospheric pressure has decreased to a certain fraction of its value at sea level B. It depends on the model adopted for the atmosphere: for an isothermal atmosphere, the pressure decreases exponentially with altitude. If H is taken as the altitude at which the pressure has fallen to B/e, then H = RT/g where R is the gas constant for air, T is the absolute temperature T, and g is the acceleration due to gravity. 大氣壓力降低到其在海平面B處數值的某一部分的高度H。它取決于大氣采用的模型：對于等溫大氣，壓力隨高度呈指數下降。如果取H作為壓力下降到B/e的高度，則H=RT/g，其中R是空氣的氣體常數，T是絕對溫度T，g是重力引起的加速度。 |
| Scatter | 分散 |
Data points or calculations are said to be scattered when they are not all the same. A ‘‘lot of scatter in preload’’ means wide variation in the preloads found in individual bolts. 當數據點或計算不盡相同時，它們被稱為分散的。“預載的大量分散”意味著單個螺栓中的預載差異很大。 |
| Scleroscope hardness number (HSc or HSd) | 硬化鏡硬度值（HSc或HSd） |
A number related to the height of rebound of a diamond-tipped hammer dropped on the material being tested. It is measured on a scale determined by dividing into 100 units the average rebound of the hammer from a quenched(to maximum hardness) and untempered AISI W5 tool steel test block. 與落在被測材料上的菱形錘的回彈高度相關的數字。通過將錘子從淬火（達到最大硬度）和未淬火的AISI W5工具鋼試塊上的平均回彈分為100個單位來測量。 |
| Scleroscope hardness test | 反躍式硬度試驗 |
A dynamic indentation-hardness test using a calibrated instrument that drops a diamond-tipped hammer from a fixed height onto the surface of the material being tested. The height of rebound of the hammer is a measure of the hardness of the material. Also known as Shore hardness test. 使用校準儀器的動態壓痕硬度測試，該儀器將金剛石錘從固定高度落在被測材料表面上。錘的回彈高度是材料硬度的一種度量。也稱為肖氏硬度測試。 |
| Scoring | 劃痕 |
In tribology, a severe form of wear characterized by the formation of extensive grooves and scratches in the direction of sliding. 在摩擦學中，一種嚴重的磨損形式，其特征是在滑動方向上形成大面積的凹槽和劃痕。 |
| Scragging machine | 刮擦機 |
1. A machine to test springs by impulsive loading 2. A machine to increase the service life of coil springs by compressing them to their minimum solid length before use, thereby inducing favourable residual stresses. 1.一種通過沖擊載荷測試彈簧的機器2.一種在使用前將螺旋彈簧壓縮至其最小實心長度以提高其使用壽命的機器，從而產生有利的殘余應力。 |
| Scratch hardness | 劃痕硬度 |
The resistance of a material, such as a metal, alloy, plastic, or mineral, to scratching by a much harder indenter, such as a diamond stylus, moved slowly across the surface. The scratch hardness number is computed from the loads and the dimensions of the residual scratch. 一種材料（如金屬、合金、塑料或礦物）對更硬的壓頭（如金剛石觸針）劃傷的抵抗力，在表面上緩慢移動。根據載荷和殘余劃痕的尺寸計算劃痕硬度值。 |
| Scratch hardness test | 劃痕硬度測試 |
A form of hardness test in which a sharp-pointed stylus or corner of a mineral specimen is traversed along a surface so as to determine the resistance of that surface to cutting or abrasion. 硬度測試的一種形式，用尖頭筆或礦物樣品的一角沿一個表面移動，以確定該表面的抗切割或耐磨性。 |
| Scratching | 刮擦 |
In tribology, the mechanical removal or displacement, or both, of material from a surface by the action of abrasive particles or protuberances sliding across the surfaces. 在摩擦學中，通過在表面上滑動的磨粒或突起的作用，材料從表面上的機械移除或移位，或兩者兼而有之。 |
| Screw | 螺釘 |
Threaded fastener designed to be used in a tapped or untapped (e.g., wood screw) hole, but not with a nut. A fastener with a screw thread cut or rolled into its cylindrical or conical shank, intended either to cut its own thread (as in a wood screw) or engage in a threaded hole. A self-tapping screw (sheet-metal screw, tapping screw) has a sufficiently hard thread that it cuts an internal thread in thin sheet or a component made of soft material when driven into a hole in the sheet or component. The screw head is the part of a screw used to apply torque to the screw. Common screw-head designs are circular in cross section with a diametral slot or cross, or hexagonal and recessed with a cross or hexagon. A screw thread is one or more continuous helical grooves of uniform section along either the exterior surface (male thread) or the interior surface (female thread) of a cylindrical or conical body. The three-dimensional shape that results when the thread cross section is rotated and axially advanced along an axis is called a helicoid, the angle that the thread makes when projected on to the axis being called the angle of inclination. Threads are employed in fasteners such as bolts, nuts, and screws; location and measuring instruments; in power drives; in some electrical fittings (Edison thread); and on the ends of crankshafts to suppress oil leakage (thrower thread). Parallel threads are formed on cylinders; tapered threads on cones, typically with a taper rate of 1:16. A screw with a righthanded thread appears to move away from the observer when turned clockwise. All standard screws, bolts and nuts have right-hand threads, but left-handed threads are sometimes employed. The axial distance between corresponding points on adjacent threads is called the screw pitch or screw rate and, for a single continuous helical groove (a single-start thread), is the same as the change in axial distance (the lead) between a nut and the head of a bolt during one revolution, the number of thread forms per mm then being the reciprocal of the pitch. For the same screw diameter, coarse threads have fewer threads per mm than fine threads. A multiple-start screw thread (usually coarse, see later) consists of two or more identical threads running simultaneously along its axis so as to provide greater bearing area and greater velocity ratio. The starts are separated by 180° (double start), 120° (triple start), 90° (quadruple start) etc., depending upon the number of threads. Thus, in double-start threads, the lead is twice the pitch; and so on. The axial distance between corresponding points on two adjacent threads in a multiple start thread is called the divided pitch. The position on a screw thread where there is equal distance between the flanks on the solid part of the thread and in the space between the threads is the pitch point, the associated diameter of which is termed the pitch diameter. The basic nomenclature for threads, some of which is common with that for toothed gearing, is shown in the diagrams. A helix formed or cut on a cylindrical surface which may advance along the axis to the right or left. The helix may be single or multiple. 一種螺紋緊固件，設計用于攻絲或未攻絲（如木螺釘）孔，但不與螺母配合使用。其螺紋被切割或卷成圓柱形或錐形柄，用于切割自身螺紋（如木螺釘）或嵌入螺紋孔。自攻螺釘（鈑金螺釘、自攻螺釘）具有足夠硬的螺紋，當打入薄板或部件中的孔時，它會在薄板或軟材料部件中切割內螺紋。螺釘頭是螺釘的一部分，用于向螺釘施加扭矩。常見的螺釘頭設計為橫截面為圓形，帶有直徑槽或十字，或為六邊形，并帶有十字或六邊形凹槽。螺紋是沿圓柱形或錐形體的外表面（外螺紋）或內表面（內螺紋）具有均勻截面的一個或多個連續螺旋槽。當螺紋橫截面旋轉并沿軸軸向前進時產生的三維形狀稱為螺旋面，螺紋投影到軸上時形成的角度稱為傾角。螺紋用于緊固件，如螺栓、螺母和螺釘；定位和測量儀器；在動力驅動中；在一些電氣配件中（愛迪生螺紋）；并安裝在曲軸端部，以抑制漏油（拋擲器螺紋）。在圓柱體上形成平行螺紋；圓錐上的錐形螺紋，通常具有1:16的錐形率。當順時針旋轉時，具有右手螺紋的螺釘似乎會遠離觀察者。所有標準螺釘、螺栓和螺母都有右手螺紋，但有時使用左手螺紋。相鄰螺紋上對應點之間的軸向距離稱為螺距或螺紋率，對于單個連續螺旋槽（單個起始螺紋），與螺母和螺栓頭之間的軸向間距（導程）在一周內的變化相同，每mm的螺紋形式數為螺距的倒數。對于相同的螺釘直徑，粗螺紋的每毫米螺紋數少于細螺紋。多頭螺紋（通常為粗螺紋，見下文）由兩個或多個沿其軸線同時延伸的相同螺紋組成，以提供更大的承載面積和更大的速比。根據螺紋的數量，起點之間的間隔為180°（雙起點）、120°（三起點）、90°（四起點）等。因此，在雙起始螺紋中，導程是螺距的兩倍；多起點螺紋中兩個相鄰螺紋上對應點之間的軸向距離稱為分割螺距。螺紋上的位置，即螺紋實體部分的側面和螺紋之間的空間之間的距離相等，即節點，其相關直徑稱為節徑。圖中顯示了螺紋的基本術語，其中一些與齒輪傳動的基本術語相同。在圓柱面上形成或切割的螺旋線，可沿軸線向右或向左前進。螺旋可以是單個或多個。 |
| Screw area (Unit m2) | 螺絲面積（單位m2） |
The area of a circle described by the tips of a propeller. 螺旋槳尖端所描述的圓的面積。 |
| Screw compressor | 螺桿壓縮機 |
A positive-displacement rotary compressor in which gas is progressively compressed by two intermeshing, counter-rotating, helical screws. 一種容積式旋轉壓縮機，其中氣體由兩個相互嚙合、反向旋轉的螺旋螺桿逐漸壓縮。 |
| Screw conveyor | 螺旋輸送機 |
(auger, spiral conveyor, worm conveyor) A machine for bulk handling of semi-solid materials, consisting of a helical screw which rotates in a trough or casing. （螺旋輸送機、螺旋輸送機、蝸桿輸送機）一種用于散裝搬運半固態材料的機器，由在槽或外殼中旋轉的螺旋螺桿組成。 |
| Screw displacement | 螺桿位移 |
A rotation of a rigid body about an axis accompanied by a translation of the body along the same axis. 剛體繞軸旋轉，同時剛體沿同一軸平移。 |
| Screw extractor | 螺釘拔 |
A device for removing broken-off screws from threaded holes. It resembles a drill with, for broken right-hand threads, a fast (long-pitch) left-hand thread that is driven into a hole drilled in the broken screw, thus untwisting it. 從螺紋孔中去除斷裂螺釘的裝置。它類似于一個鉆頭，對于斷裂的右螺紋，一個快速（長螺距）的左螺紋被打入在斷裂螺釘上鉆的孔中，從而將其松開。 |
| Screw feeder | 螺旋給料機 |
A mechanism for handling bulk materials in which a rotating helicoidal screw moves the material axially forward. Similar to a screw conveyor, but required to discharge material at a controlled rate very accurately. It operates with the screw completely full. 一種用于處理散裝物料的機構，其中旋轉的螺旋螺桿使物料軸向向前移動。類似于螺旋輸送機，但需要以受控速率非常精確地排出物料。它在螺桿完全充滿的情況下運行。 |
| Screw jack | 螺旋千斤頂 |
A lifting device (jack) consisting of a nut and square-threaded shaft at the top of which is a load-bearing pad. Rotation of the nut raises or lowers the pad. 一種起重裝置（千斤頂），由螺母和方形螺紋軸組成，其頂部為承重墊。螺母的旋轉可升高或降低襯墊。 |
| Screw machine | 螺絲機 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一種用棒或棒大批量制造小零件的機床。 |
| Screw pair | 螺旋副 |
Two links connected together to form a kinematic pair, in which the contacting surfaces are screw threads, so that their relative motion consists of rotation and sliding. 兩個連桿連接在一起形成運動副，其中接觸面為螺紋，因此它們的相對運動包括旋轉和滑動。 |
| Screw pump | 螺桿泵 |
A positive-displacement pump that uses one or more helical rotors rotating within a casing to transfer liquids or slurries. 一種容積式泵，使用一個或多個在外殼內旋轉的螺旋轉子輸送液體或泥漿。 |
| Screw thread | 螺紋 |
A ridge of uniform section or shape in the form of a helix on the external or internal surface of a cylinder, or in the form of a conical spiral on the external or internal surface of a cone. 在圓柱體的外表面或內表面上呈螺旋形或在圓錐體的外表面和內表面上以錐形螺旋形的均勻截面或形狀的脊。 |
| Scuffing | 擦傷 |
A form of adhesive wear that produces superficial scratches or a high polish on the rubbing surfaces. It is observed most often on inadequately lubricated parts. 粘著磨損的一種形式，在摩擦表面上產生表面劃痕或高度拋光。通常在潤滑不足的零件上觀察到。 |
| Seal | 密封件 |
A component which controls or prevents leakage of fluids into or out of parts of a machine. 控制或防止流體流入或流出機器部件的部件。 |
| Secant modulus | 割線模量 |
The slope of the secant drawn from the origin to any specified point on a stress-strain curve. Compare with chord modulus. 從原點到應力應變曲線上任何指定點的割線斜率。與弦模量進行比較。 |
| Second (s) | 秒（s） |
The SI base unit of time equal to 9 192 631 770 times the period of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. SI基時間單位等于9192631770倍的輻射周期，對應于銫-133原子基態的兩個超精細能級之間的躍遷。 |
| Secondary hardening | 二次硬化 |
The process whereby some low-alloy steels, quenched to produce martensite, produce fine precipitates when tempered above 550°C, which inhibit dislocation motion and reverse the trend towards lower strength at higher tempering temperatures. 某些低合金鋼經淬火產生馬氏體，在550°C以上回火時產生細小沉淀的過程，這抑制了位錯運動，扭轉了在較高回火溫度下強度降低的趨勢。 |
| Secondary stresses (Unit Pa) | 二次應力（單位Pa） |
Stresses different from those induced by the major loading but nevertheless resulting from the major loads; for example, the hoop stresses that occur around the circumference of barrelled compression testpieces and forgings. 與主要荷載引起的應力不同，但主要荷載產生的應力；例如，桶裝壓縮試件和鍛件周圍產生的環向應力。 |
| Selective heating | 局部加熱 |
Intentionally heating only certain portions of a workpiece. 有意僅加熱工件的某些部分。 |
| Selective quenching | 局部淬火 |
Quenching only certain portions of an object. 僅淬火工件的某些部分。 |
| Self-locking nut | 自鎖螺母 |
A nut with an inherent locking action which minimizes loosening due to vibration. A self-locking screw locks itself in place without the need for a separate selflocking nut or lock washer. 一種具有固有鎖定作用的螺母，可將振動引起的松動降至最低。自鎖螺釘將自身鎖定到位，無需單獨的自鎖工件或鎖緊墊圈。 |
| Self-loosening | 自松動 |
The process by which a supposedly tightened fastener becomes loose, as a result of vibration, thermal cycles, shock, or anything else which cause transverse slip between joint members and between male and female threads. Vibration loosening is a common, but special, case of self-loosening. 由于振動、熱循環、沖擊或任何其他導致接頭構件之間以及陽螺紋和陰螺紋之間橫向滑動的原因，緊固件松動的過程。振動松動是自松動的一種常見但特殊的情況。 |
| Semi-rotary pump | 半回轉泵 |
A form of self-priming pump, often hand-operated, suitable for pumping water and light oils such as diesel oil and petrol. As shown in the diagram, liquid is sucked into one side of the pump through flap valves and simultaneously ejected from the other side on one stroke. The sequence is reversed on each successive stroke. 一種自吸泵，通常是手動的，適用于泵送水和輕油，如柴油和汽油。液體通過翻板閥吸入泵的一側，同時在一個沖程中從另一側排出。在每個連續沖程上，順序顛倒。 |
| Semiguided bend | 半導彎曲 |
The bend obtained by applying a force directly to the specimen in the portion that is to be bent. The specimen is either held at one end and forced around a pin or rounded edge, or is supported near the ends and bent by a force applied on the side of the specimen opposite the supports and midway between them. In some instances, the bend is started in this manner and finished in the manner of a free bend. 通過將力直接施加于待彎曲部分中的試樣而獲得的彎曲。將試樣固定在一端，并圍繞銷或圓邊施力，或者在靠近端部的位置支撐試樣，并通過施加在試樣與支撐件相對的一側以及兩者中間的力進行彎曲。在某些情況下，折彎以此方式開始，然后以自由折彎的方式結束。 |
| Serrations | 鋸齒 |
A row of notches or tooth-like projections on an edge or surface. On an engineering drawing, serrations on the surface of a circular component are shown over about 60° of arc. 邊緣或表面上的一排凹口或齒狀突起。在工程圖紙上，圓形部件表面的鋸齒超過約60°的圓弧。 |
| Set pressure (Unit Pa) | 設定壓力（單位Pa） |
The pressure at which a relief valve or safety valve is set to open, corresponding to the relevant code or standard which applies to the pressure vessel being protected. 安全閥或安全閥開啟時的壓力，對應于適用于受保護壓力容器的相關規范或標準。 |
| Set screw | 緊定螺釘（平頭螺釘、緊定螺栓） |
Usually a hardened steel screw having either no head or a square head and with various degrees of points or ends to lock or tighten adjustable machine parts in position on a shaft. A short, headless screw with a recess at one end to receive a screwdriver or key, the other end being pointed, square, or otherwise shaped. Typically used to secure a pulley, gear, or other component on a shaft. 通常是一種硬化鋼螺釘，無頭或方頭，具有不同程度的點或端部，用于將可調機械部件鎖定或擰緊在軸上的適當位置。一端有凹槽，用來裝螺絲刀或鑰匙，另一端是尖的、方形的或其他形狀的。通常用于將皮帶輪、齒輪或其他部件固定在軸上。 |
| Shank | 螺桿 |
Portion of a bolt which lies under the head. 1. The stem of a tool, such as a broach, drill bit, reamer, or tap, which fits into a holder such as a chuck. 2. The stem of a rivet or the unthreaded part of a screw or bolt. 3. The shaft of a tool connecting the tip and the handle. 螺栓頭部下方的部分。1.一種工具的柄部，如拉刀、鉆頭、鉸刀或絲錐，可裝入夾具（如卡盤）中。鉚釘的桿或螺釘或螺栓的無螺紋部分。3.連接尖端和手柄的工具的軸。 |
| Sharp-notch strength | 銳缺口強度 |
The notch tensile strength measured using specimens with very small notch root radii (approaching the limit for machining capability); values of sharp-notch strength usually depend on notch root radius. 使用缺口根部半徑非常小（接近加工能力極限）的試樣測量的缺口抗拉強度；銳缺口強度值通常取決于缺口根部半徑。 |
| Shear | 扭剪 |
The type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. 導致或傾向于導致同一物體的兩個相鄰部分在平行于其接觸面的方向上相對滑動的力的類型。 |
| Shear fracture | 剪切斷裂 |
A ductile fracture in which a crystal (or a polycrystalline mass)has separated by sliding or tearing under the action of shear stresses. Contrast with cleavage fracture. 在剪切應力作用下，晶體（或多晶塊）通過滑動或撕裂而分離的韌性斷裂。與解理斷裂形成對比。 |
| Shear joint | 剪切接頭 |
A joint which is subjected primarily to loads acting more or less perpendicular to the axes of the bolts. 主要承受或多或少垂直于螺栓軸線的載荷的接頭。 |
| Shear lip | 剪切唇 |
A narrow, slanting ridge along the edge of a fracture surface. The term sometimes also denotes a narrow, often crescent-shaped, fibrous region at the edge of a fracture that is otherwise of the cleavage type, even though this fibrous region is in the same plane as the rest of the fracture surface. 沿斷裂面邊緣的狹窄傾斜脊。該術語有時還表示斷裂邊緣處的狹窄、通常為新月形的纖維區域，否則為解理型，即使該纖維區域與斷裂表面的其余部分位于同一平面內。 |
| Shear modulus (G) | 剪切模量（G） |
The ratio of shear stress to the corresponding shear strain for shear stresses below the proportional limit of the material. Values of shear modulus are usually determined by torsion testing. Also known as modulus of rigidity. 對于低于材料比例極限的剪切應力，剪切應力與相應剪切應變之比。剪切模量值通常通過扭轉試驗確定。也稱為剛度模量。 |
| Shear strain | 剪切應變 |
The tangent of the angular change, as a response to force, between two lines originally perpendicular to each other through a point in a body. Also known as shearing strain. 角變化的切線，作為對力的響應，在兩條原本通過物體中的一個點相互垂直的線之間。也稱為剪切應變。 |
| Shear strain rate(Unit 1/s) | 剪切應變率（單位1/s） |
In the deformation of solids, the rate at which shear strain is applied in a test or changes with time in a loaded component or structure. 在固體變形中，在試驗中施加剪切應變的速率，或在加載部件或結構中隨時間變化的速率。 |
| Shear strength | 抗剪強度 |
The maximum shear stress that a material is capable of sustaining. Shear strength is calculated from the maximum load during a shear or torsion test and is based on the original dimensions of the cross section of the specimen. 材料能夠承受的最大剪切應力。抗剪強度根據剪切或扭轉試驗期間的最大載荷計算，并基于試樣橫截面的原始尺寸。 |
| Shear strength (Unit Pa) | 抗剪強度（單位Pa） |
The maximum shear stress that can be withstood by a material either (a) before plasticity occurs or (b) before rupture. 材料在（a）塑性發生之前或（b）斷裂之前能夠承受的最大剪切應力。 |
| Shear stress (Unit Pa) | 剪應力（單位Pa） |
(1) A stress that exists when parallel planes in metal crystals slide across each other. (2) The stress component tangential to the plane on which the forces act. Also known as tangential stress. (shearing stress, tangential stress, τ) 1. The stress which acts parallel to any plane within a solid material. It can arise due to a bending moment, a shear force, or torque applied to the body. 2. The stress corresponding to velocity gradients within a flowing viscous fluid. （剪應力，切向應力，τ）（1）當金屬晶體中的平行平面彼此滑動時存在的應力。（2）與力作用平面相切的應力分量。也稱為切向應力。1.平行于固體材料內任何平面的應力。它可能是由于施加在身體上的彎矩、剪力或扭矩引起的。2.對應于流動粘性流體內的速度梯度的應力。 |
| Shear test | 剪切試驗 |
Any of several tests to obtain shear strength of a metal. Common tests used on mill products include the double-shear test, single-shear test, the blanking shear test (also known as the punching shear test) and the torsion test. 獲得金屬剪切強度的幾種測試中的任何一種。軋機產品上常用的試驗包括雙剪試驗、單剪試驗、落料剪切試驗（也稱為沖切試驗）和扭轉試驗。 |
| Shell hardening | 殼型硬化 |
A surface-hardening process in which a suitable steel workpiece, when heated through and quench hardened, develops a martensitic layer or shell that closely follows the contour of the piece and surrounds a core of essentially pearlitic transformation product. This result is accomplished by a proper balance among section size, steel hardenability, and severity of quench. 一種表面硬化工藝，在該工藝中，合適的鋼工件在加熱和淬火硬化后，會形成一層馬氏體層或殼，該層或殼緊隨工件的輪廓，并包圍一個基本上為珠光體相變產物的核心。這一結果通過截面尺寸、鋼淬透性和淬火強度之間的適當平衡來實現。 |
| Shim | 墊片 |
A thin piece of material, such as metal of accurately-known thickness, placed between two surfaces to ensure they are the correct distance apart. A thin piece of material placed between two surfaces to obtain a proper fit, adjustment, or alignment. The piece can also be analyzed to measure furnace carbon potential (that is, because while in the furnace it will quickly carburize to a level equal to the furnace carbon potential). 一塊薄的材料，如厚度精確已知的金屬，放置在兩個表面之間，以確保它們之間的距離正確。放置在兩個表面之間以獲得適當配合、調整或對齊的一塊薄材料。還可以對工件進行分析，以測量熔爐碳勢（也就是說，在熔爐中，工件將快速滲碳至與熔爐碳勢能相等的水平）。 |
| Shock load | 沖擊載荷 |
The sudden application of an external force that results in a very rapid build-up of stress. 突然施加外力，導致應力迅速增加。 |
| Shore hardness | 肖氏硬度 |
A measure of the hardness of materials such as elastomers, plastics, and rubbers determined using a Shore durometer which measures the penetration depth of a hardened steel rod (the indenter) 1.1–1.4 mm in diameter into the test material for a given force applied rapidly with a calibrated spring. There are two main indenter designs: type A (for softer materials) for which the end of the rod is a truncated 35° cone tapering to a diameter of 0.79 mm, and type D (harder materials) for which the end is a 30° cone with a 0.1 mm radius tip. The spring force is 8.05 N for type A and 44.45 N for type D. The hardness value is related to the penetration depth (limited to a maximum of 2.5 mm) such that for zero penetration the hardness is 100 and for maximum penetration the hardness is zero. The relevant standards are ISO 48-1, 48-4, and 48-7. Shore hardness values of selected materials are as follows: ABS 100, cellulose acetate 50–95, high-density polyethylene 60–70, low density polyethylene 40–50, polymethylmethacrylate 90–99, PTFE 50–65, and plasticized PVC 15–70. 使用肖氏硬度計測量彈性體、塑料和橡膠等材料的硬度，肖氏硬度儀測量直徑為1.1–1.4mm的硬化鋼棒（壓頭）在用校準彈簧快速施加的給定力下滲入試驗材料的深度。有兩種主要的壓頭設計：A型（適用于較軟的材料），其桿端為截頭35°錐形，逐漸變細至直徑0.79 mm；D型（較硬的材料），端部為30°錐形，尖端半徑為0.1mm。A型的彈簧力為8.05N，D型為44.45N。硬度值與滲透深度相關（最大限制為2.5mm），因此，對于零滲透，硬度為100，對于最大滲透，硬度是零。相關標準為ISO 48-1、48-4和48-7。所選材料的肖氏硬度值如下：ABS100、醋酸纖維素50-95、高密度聚乙烯60-70、低密度聚乙烯40-50、聚甲基丙烯酸甲酯90-99、PTFE50-65和塑化PVC15-70。 |
| Shoulder | 軸肩 |
The portion of a shaft, stepped component, or flanged component, where a change in diameter or other dimension occurs. Even for a nominal step change, in practice there will be a radius where shoulder and shaft meet in order to avoid too severe a stress concentration. 軸、階梯部件或法蘭部件的直徑或其他尺寸發生變化的部分。即使是名義階躍變化，在實踐中，肩部和軸相交處也會有一個半徑，以避免出現過嚴重的應力集中。 |
| Shoulder bolt | 軸肩螺栓 |
A bolt for which the unthreaded cylindrical section between the thread and the head is of larger diameter than the threaded section, precisely machined to length and diameter and hardened 一種螺栓，其螺紋和頭部之間的無螺紋圓柱段的直徑大于螺紋段的直徑，精確加工至長度和直徑并硬化 |
| Shoulder joint | 軸肩關節 |
The second joint on an articulated robot, which has a horizontal axis and is analogous to the human shoulder. 關節機器人上的第二個關節，具有水平軸，類似于人的肩膀。 |
| Shoulder screw | 軸肩螺釘 |
A screw having two or more diameters or shoulders and commonly used for supporting levers and other machine parts that have to operate freely. 一種具有兩個或兩個以上直徑或軸肩的螺釘，通常用于支撐杠桿和其他必須自由操作的機器部件。 |
| Shrink fit | 過盈配合 |
A tight interference fit between two components resulting from heating an outer part and/or cooling an inner part to allow easy assembly. The outer component contracts on cooling, while the inner part expands on warming to ambient temperature, thus gripping the two parts together. 由于加熱外部部件和/或冷卻內部部件而導致的兩個部件之間的緊密過盈配合，以便于組裝。外部部件在冷卻時收縮，而內部部件在加熱到環境溫度時膨脹，從而將兩個部件夾在一起。 |
| Shrink ring | 預緊環 |
A ring, which is expanded by heating, is placed around an assembly of parts, and then contracts upon cooling to hold the assembly in place. 通過加熱膨脹的環被放置在零件組件周圍，然后在冷卻時收縮以將組件固定到位。 |
| SI system | SI國際單位制 |
SI is an abbreviation of Système International d’Unités, i.e., the international unit measurement system – an internationally established system of measurement units built on older metric systems. SI是Système International d‘Unités的縮寫，即國際單位計量系統——一種基于舊公制的國際公認計量單位系統。 |
| Sigma phase | σ相 |
A hard, brittle, nonmagnetic intermediate phase with a tetragonal crystal structure, containing 30 atoms per unit cell, space group P42/mnm, occurring in many binary and ternary alloys of the transition elements. The composition of this phase in the various systems is not the same, and the phase usually exhibits a wide range in homogeneity. Alloying with a third transition element usually enlarges the field of homogeneity and extends it deep into the ternary section. 一種硬、脆、非磁性中間相，具有四方晶體結構，每單位晶胞含有30個原子，空間群P42/mnm，存在于許多過渡元素的二元和三元合金中。該相在各種系統中的組成不盡相同，并且該相通常表現出寬范圍的均勻性。與第三過渡元素的合金化通常會擴大均勻性范圍，并將其延伸到三元區。 |
| Sigma-phase embrittlement | σ相脆化 |
Embrittlement of iron-chromium alloys (most notably austenitic stainless steels) caused by precipitation at grain boundaries of the hard, brittle intermetallic sigma phase during long periods of exposure to temperatures between approximately 565 and 980 °C (1050 and 1800 °F). Sigmaphase embrittlement results in severe loss in toughness and ductility and can make the embrittled material structure susceptible to intergranular corrosion. 鐵鉻合金（最顯著的是奧氏體不銹鋼）的脆化是由于在長時間暴露于約565至980°C（1050至1800°F）的溫度下，硬脆金屬間化合物σ相的晶界處沉淀造成的。σ相脆化導致韌性和延展性的嚴重損失，可使脆化的材料結構易于發生晶間腐蝕。 |
| Significance level | 顯著性水平 |
The stated probability (risk) that a given test of significance will reject the hypothesis that a specified effect is absent when the hypothesis is true. 當假設為真時，給定的顯著性檢驗將拒絕特定效應不存在的假設的所述概率（風險）。 |
| Silky fracture | 絲狀斷口 |
A metal fracture in which the broken metal surface has a fine texture, usually dull in appearance. Characteristic of tough and strong metals. 一種金屬斷裂，斷裂的金屬表面具有精細的紋理，通常外觀暗淡。具有堅韌和堅固金屬的特征。 |
| Single thread | 單頭螺紋 |
A screw thread cut around a cylinder having a single start in which the lead is equal to the pitch. 一種螺紋，在一個圓柱體上切割而成，具有一個單一的起點，在這個起點上，導程等于螺距。 |
| Single-shear test | 單剪試驗 |
?(1) A shear test similar to the double-shear test used for round-bar specimens, but that uses only one stationary shear blade. (2) A shear test that uses a sheet or thin-plate specimen. （1）一種剪切試驗，類似于用于圓棒試樣的雙剪切試驗，但僅使用一個固定剪切刀片。（2）使用薄板或薄板試樣的剪切試驗。 |
| Sinter (sintering) | 燒結 |
A solid-state diffusion densification process for the production of objects, particularly porous objects, from raw material in powder, granular, mesh, perforatedsheet, or fibre form by heating to a temperature below the melting point until the constituents bond together. It is used for ceramic materials and metals. Applications of sintered materials include filtration, separation, flow control, fluidization, and noise reduction. The bonding of adjacent surfaces in a mass of particles by molecular or atomic attraction on heating at high temperatures below the melting temperature of any constituent in the material. Sintering strengthens a powder mass and normally produces densification and, in powdered metals, recrystallization. 一種固態擴散致密化工藝，用于從粉末、粒狀、網狀、穿孔片或纖維形式的原材料中生產物體，尤其是多孔物體，方法是加熱至低于熔點的溫度，直到成分結合在一起。它用于陶瓷材料和金屬。燒結材料的應用包括過濾、分離、流量控制、流化和降噪。在低于材料中任何成分熔化溫度的高溫下加熱時，通過分子或原子引力將大量顆粒的相鄰表面結合起來。燒結增強了粉末質量，通常會產生致密化，在粉末金屬中還會產生再結晶。 |
| Size dimension (Unit m) | 尺寸范圍（單位：米） |
The specified value of a diameter, length, width, etc. of a feature required to specify the finished form of a component or assembly. 指定部件或組件的成品形狀所需的特征的直徑、長度、寬度等的指定值。 |
| Size effect | 尺寸效應 |
Effect of the dimensions of a piece of metal on its mechanical and other properties and on manufacturing variables such as forging reduction and heat treatment. In general, the mechanical properties are lower for a larger size. 金屬件的尺寸對其機械和其他性能以及對制造變量（如鍛造、壓下和熱處理）的影響。一般來說，尺寸越大，機械性能越低。 |
| Sizing | 顆粒化 |
1. A finishing operation to ensure the specified dimensions and tolerances for a component are met. 2. (size classification) Separating an aggregate of mixed particles into groups according to size using a series of screens. 1.精加工操作，以確保滿足部件的規定尺寸和公差。2.（粒度分類）使用一系列篩網根據粒度將混合顆粒的聚集體分成組。 |
| Slack quenching | 欠速淬火 |
The incomplete hardening of steel due to quenching from the austenitizing temperature at a rate slower than the critical cooling rate for the particular steel, resulting in the formation of one or more transformation products in addition to martensite. 由于從奧氏體化溫度以低于特定鋼臨界冷卻速度的速度淬火而導致鋼的不完全硬化，導致除馬氏體外還形成一種或多種相變產物。 |
| Slant fracture | 傾斜裂縫 |
A type of fracture appearance, typical of plane-stress fractures, in which the plane of metal separation is inclined at an angle (usually about 45°) to the axis of the applied stress. 一種斷裂現象，典型的平面應力斷裂，其中金屬分離面與施加應力的軸成一定角度（通常約45°）傾斜。 |
| Slenderness ratio | 長細比 |
The effective unsupported length of a uniform column divided by the least radius of gyration of the cross-sectional area. 均勻柱的有效無支撐長度除以橫截面積的最小回轉半徑。 |
| Sliding-vane compressor | 滑片壓縮機 |
(rotary-vane compressor, vane compressor) A rotary compressor in which gas is compressed as the spaces between spring-loaded sliding vanes held in an offset rotor reduce as the rotor revolves within a cylindrical housing. （旋轉葉片壓縮機，葉片壓縮機）一種旋轉式壓縮機，當轉子在圓柱形外殼內旋轉時，偏置轉子中的彈簧加載滑動葉片之間的空間減小，從而壓縮氣體。 |
| Slip | 滑落 |
Plastic deformation by the irreversible shear displacement (translation)of one part of a crystal relative to another in a definite crystallographic direction and usually on a specific crystallographic plane. Sometimes called glide. 晶體的一部分在一定的晶體學方向上相對于另一部分的不可逆剪切位移（平移）引起的塑性變形，通常在特定的晶體主義平面上。有時被稱為滑翔。 |
| Slip band | 滑帶 |
A group of parallel slip lines so closely spaced as to appear as a single line when observed under an optical microscope. 一組平行滑移線，間距如此之近，以至于在光學顯微鏡下觀察時顯示為一條直線。 |
| Slip joint | 滑動接頭 |
A mechanical connection which allows limited endwise relative movement of two components such as pipes, rods, and ducts. 一種機械連接，允許兩個部件（如管道、桿和管道）進行有限的軸向相對運動。 |
| Slip line | 滑移線 |
The trace of the slip plane on a viewing surface; the trace is usually observable only if the surface has been polished before deformation. The usual observation on metal crystals (under the light microscope) is of a cluster of slip lines known as a slip band. 滑動平面在觀察表面上的軌跡；只有在變形前對表面進行拋光，才能觀察到痕跡。通常對金屬晶體的觀察（在光學顯微鏡下）是一組稱為滑移帶的滑移線。 |
| Slot | 狹槽 |
A groove machined into a component, e.g. to allow for thermal expansion, or in which the tongue or tip of another component can fit or slide. 在部件上加工的凹槽，例如，允許熱膨脹，或另一部件的榫舌或尖端可在其中安裝或滑動。 |
| Slug | 猛擊 |
1. A starting workpiece for forging and similar operations, such as a length of wire or rod to make a bolt blank on which a thread can be rolled or cut. 2. (geepound) An obsolete imperial (non-SI) unit of mass, being the mass which under an acceleration of one foot per second squared gives a force of one pound-force. The conversion to SI is 1 slug = 14.593 902 94 kg. 3. A large-scale flow structure which occurs in the transition from laminar to turbulent flow in a pipe. 1.一種用于鍛造和類似操作的起始工件，如用于制造螺栓毛坯的一段線材或棒材，在該毛坯上可以軋制或切割螺紋。2.（吉磅）一種已被淘汰的英制（非國際單位制）質量單位，在一英尺/秒平方加速度下產生一磅力的質量。轉化為SI國際單位制的轉化率為1slug=14.59390294kg。3.一種大規模流動結構，其發生在管道中從層流到湍流的過渡中。 |
| Slug wrench | 緩動扳手 |
A box wrench with an anvil on the end of the handle. Torque is produced by striking the anvil with a sledge hammer. 柄端有鐵砧的套筒扳手。扭矩是通過用大錘敲擊鐵砧產生的。 |
| Snap temper | 快速回火 |
A precautionary interim stress-relieving treatment applied to high-hardenability steels immediately after quenching to prevent cracking because of delay in tempering them at the prescribed higher temperature. 在淬火后立即對高淬透性鋼進行預防性臨時應力消除處理，以防止因在規定的更高溫度下回火延遲而開裂。 |
| Socket head | 凹頭 |
Screw head having a hexagonal or other form of recessed socket in the head so that the screw can be turned with a wrench or key, as a hexagon key. 螺釘頭上有六角或其他形式的凹座，可以用扳手或鑰匙（如六角鑰匙）轉動螺釘。 |
| Socket wrench | 套筒扳手 |
A form of spanner with an internally ridged steel socket to fit a nut or the head of a bolt or screw. 扳手的一種形式，帶有內脊鋼套筒，用于安裝螺母或螺栓或螺釘的頭部。 |
| Solenoid | 螺線管 |
A coil of electrically-conducting wire wrapped around a metal core, typically iron, to produce a magnetic field and hence a force on the core when an electric current passes through the coil. Solenoids are widely used to produce linear movement to actuate valves (solenoid valves) and other devices. 繞在金屬芯（通常為鐵）上的導線線圈，當電流通過線圈時產生磁場，從而在芯上產生力。電磁閥廣泛用于產生線性運動以驅動閥（電磁閥）和其他裝置。 |
| Solution heat treatment | 固溶熱處理 |
Heating an alloy to a suitable temperature, holding at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooling rapidly enough to hold these constituents in solution. 將合金加熱到合適的溫度，在該溫度下保持足夠長的時間以使一種或多種成分進入固溶體，然后快速冷卻以將這些成分保持在溶液中。 |
| Sound pressure (Unit μPa) | 聲壓（單位：μPa） |
The instantaneous deviation of pressure from the ambient pressure caused by the passage of a sound wave, which can be measured by a microphone in air and a hydrophone in water. 聲波傳播引起的壓力與環境壓力的瞬時偏差，可通過空氣中的麥克風和水中的水聽器測量。 |
| Spalling | 剝落 |
The separation of macroscopic particles from a surface in the form of flakes or chips. 以薄片或碎片形式從表面分離宏觀顆粒。 |
| Span (Unit m) | 跨度（單位：m） |
A dimension measured between the extremities of a body or structure, such as between the tips of a wing or the supports of a bridge. 在身體或結構的末端之間測量的尺寸，如機翼尖端或橋梁支架之間。 |
| Spanner (wrench) | 扳手 |
A tool for applying torque to tighten or loosen a nut, bolt, or screw. Grip is applied by a serrated ring or an open U-shape at the end of the tool. On imperial-size spanners, the BSW and BSF marking refers to the diameter of the screw thread; similarly for BA spanners. Spanners for unified and metric threads are marked with the distance across the flats (‘A/F’) of the nut or head of the bolt. 擰緊或松開螺母、螺栓或螺絲的工具。通過工具端部的鋸齒環或開口U形應用夾持。在英制扳手上，BSW和BSF標記是指螺紋的直徑；類似于BA扳手。用于統一螺紋和公制螺紋的扳手在螺母或螺栓頭的平面（'A/F'）上標記距離。 |
| Specific heat capacity | 比熱容 |
The heat necessary to raise the temperature of 1 kg of a substance by 1 K. It is measured in J/(kg K). 將1千克物質的溫度升高1K所需的熱量。單位為J/（kg K）。 |
| Specific weight (γ) (Unit N/m3) | 比重（γ）（單位：N/m3） |
The weight per unit volume of a substance: if W is the weight of a volume of the substance, ρ is its density, and g is the acceleration due to gravity, γ = W/ = ρg. 物質單位體積的重量：W是物質體積的重量，ρ是其密度，g是重力引起的加速度，γ=W/=ρg。 |
| Specimen | 樣品 |
A test object, often of standard dimensions or configuration, that is used for destructive or nondestructive testing. One or more specimens may be cut from each unit of a sample. 用于破壞性或無損檢測的測試對象，通常具有標準尺寸或配置。可以從樣品的每個單位切割一個或多個樣品。 |
| Speed of rotation (N) | 轉速（N） |
(Unit rps or rpm) For an object rotating about a fixed axis, the speed of rotation is the number of turns (revolutions) of the object per unit time. It is equal to the angular velocity Ω (or ω) (unit rad/s) divided by 2π. （單位rps或rpm）對于繞固定軸旋轉的物體，旋轉速度是物體每單位時間的轉數。它等于角速度Ω（或ω）（單位rad/s）除以2π。 |
| Spherical washer | 球面墊圈 |
A washer whose upper surface is semispherical. Used with a nut whose contact face is also semispherical. Reduces bending stress in a bolt or stud, by allowing some self-alignment and some compensation for nonparallel joint surfaces or Angularity. 上表面為半球形的墊圈。與接觸面也是半球形的螺母一起使用。減少螺栓或螺柱中的彎曲應力，允許一些自對準，并對不平行的接頭表面或角度進行一些補償。 |
| Spinner | 旋轉器 |
A co-axial streamlined fairing enclosing the hub of a propeller and rotating with it. 一種同軸流線型整流罩，包圍螺旋槳轂并隨其旋轉。 |
| Spray quenching | 噴霧淬火 |
A quenching process using spray nozzles to spray water or other liquids on a part. The quench rate is controlled by the velocity and volume of liquid per unit area per unit of time of impingement. 使用噴嘴將水或其他液體噴射到零件上的淬火過程。淬火速率由每單位撞擊時間內每單位面積的液體速度和體積控制。 |
| Spring | 彈簧 |
An elastic component which stores mechanical energy and exerts a force when deformed. The slope of the curve of applied force F to the deflexion of a spring x, dF/dx, is termed the spring rate or spring modulus k with unit N/m. For a linear spring, the F(x) curve is proportional and k is called the spring constant. An elastic device which yields under stress or pressure but returns to its original state or position when the stress or pressure is removed. 儲存機械能并在變形時施加力的彈性部件。作用力F與彈簧x偏轉的曲線斜率dF/dx稱為彈簧率或彈簧模量k，單位為N/m。對于線性彈簧，F（x）曲線成比例，k稱為彈簧常數。一種彈性裝置，在應力或壓力下屈服，但在應力和壓力消除后恢復到其原始狀態或位置。 |
| Spring clip | 彈簧夾 |
A clip made of a material such as spring steel which grips an inserted part. 由彈簧鋼等材料制成的夾子，用于夾住插入的零件。 |
| Spring constant | 彈簧常數 |
The ratio between the forces exerted on a spring (or a bolt) and the deflection thereof. Has the dimensions of force per unit change in length (e.g., lb=in.). Also called Stiffness. 施加在彈簧（或螺栓）上的力與其撓度之間的比率。具有每單位長度變化的力的尺寸（例如lb=in.）。也稱為剛度。 |
| Spring load (Unit N) | 彈簧載荷（單位：N） |
A load exerted on a component by bending, compressing, extending, or twisting an attached spring. Mechanical energy stored in the spring can be released if any constraints on the component are removed. 通過彎曲、壓縮、延伸或扭轉連接的彈簧而施加在部件上的載荷。如果部件上的任何約束被移除，則可以釋放彈簧中存儲的機械能。 |
| Spring materials | 彈簧材料 |
Mainly metals including plain-carbon and corrosion-resisting steels, phosphor bronze, spring brass, beryllium copper and nickel alloys, all of which in their workhardened states permit large reversible elastic strains without permanent deformation. 主要是金屬，包括普通碳鋼和耐腐蝕鋼、磷青銅、彈簧黃銅、鈹銅和鎳合金，所有這些金屬在其加工硬化狀態下都允許大的可逆彈性應變而不會產生永久變形。 |
| Spring temper | 彈簧回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about two-thirds of the way from full hard to extra spring temper. 非鐵合金和一些鐵合金的一種回火，其特點是抗拉強度和硬度約為全硬回火到超彈性回火的三分之二。 |
| Springback | 回彈 |
The extent to which metal tends to return to its original shape or contour after undergoing a forming operation. 金屬在經歷成形操作后趨于恢復其原始形狀或輪廓的程度。 |
| Square | 正方 |
1. A regular quadrilateral, i.e. a polygon with four equal sides and four right angles. 2. An instrument to check angles of internal and external surfaces and flatness. 1.正四邊形，即具有四條等邊和四個直角的多邊形。2.一種檢查內外表面角度和平面度的儀器。 |
| Square thread | 方螺紋 |
A form of screw thread in which the cross–section of the thread forms a square, making the width of the thread equal to the space between the threads. 螺紋的一種形式，螺紋的橫截面形成正方形，使螺紋的寬度等于螺紋之間的間距。 |
| Stability | 穩定性 |
1. A term relating to whether a body, structure, system, or flow is in a state of stable, unstable, or neutral equilibrium. 2. In numerical analysis, whether numerical errors, such as roundoff or input-data errors, are damped, propagate, or cause divergence of the solution as the numerical method proceeds. 3. A control system is often described as stable when a step change in input results in a steady output without continuing oscillation. 1.與物體、結構、系統或流是否處于穩定、不穩定或中性平衡狀態有關的術語。2.在數值分析中，隨著數值方法的進行，數值誤差（如舍入誤差或輸入數據誤差）是否衰減、傳播或導致解發散。3.當輸入的階躍變化導致穩定輸出而無持續振蕩時，控制系統通常被描述為穩定的。 |
| Stabilizing treatment | 穩定化處理 |
(1) Before finishing to final dimensions, repeatedly heating a ferrous or nonferrous part to or slightly above its normal operating temperature and then cooling to room temperature to ensure dimensional stability in service. (2) Transforming retained austenite in quenched hardenable steels, usually by cold treatment. (3) Heating a solution-treated stabilized grade of austenitic stainless steel to 870 to 900 °C (1600 to 1650 °F) to precipitate all carbon as TiC, NbC, or TaC so that sensitization is avoided on subsequent exposure to elevated temperature. （1）在精加工至最終尺寸之前，反復加熱含鐵或非鐵零件至或略高于其正常工作溫度，然后冷卻至室溫，以確保使用中的尺寸穩定性。（2）在淬火可淬硬鋼中轉變殘余奧氏體，通常通過冷處理。（3）將固溶處理的穩定等級奧氏體不銹鋼加熱至870至900°C（1600至1650°F），使所有碳沉淀為TiC、NbC或TaC，從而避免在隨后暴露于高溫時敏化。 |
| Stainless steels | 不銹鋼 |
Iron-base alloys that are highly resistant to corrosion in many environments. The predominant alloying element is chromium, which, like iron at room temperature, has BCC crystal structure. Corrosion resistance by passivation is achieved by the formation of chromium oxide on the steel surface. Nickel, which has FCC crystal structure, is another important addition for some steels. Other additions used to enhance properties include manganese, molybdenum, niobium, and titanium. There are several classes of stainless steel. 在許多環境中具有高度耐腐蝕性的鐵基合金。主要的合金元素是鉻，與室溫下的鐵一樣，鉻具有BCC晶體結構。鈍化抗腐蝕性是通過在鋼表面形成氧化鉻來實現的。具有FCC晶體結構的鎳是某些鋼的另一種重要添加劑。其他用于增強性能的添加劑包括錳、鉬、鈮和鈦。不銹鋼的種類有好幾種。 |
| Standard | 標準 |
(standard specification) A set of specifications for components, machines, materials, or processes intended to achieve uniformity, efficiency, and a specified quality. In the UK, standards issued by the British Standards Institution (BSI) are now generally those of the International Organization for Standardization (ISO). （標準規范）為實現一致性、效率和特定質量而制定的一套組件、機器、材料或工藝規范。在英國，英國標準協會（BSI）發布的標準現在基本上是國際標準化組織（ISO）的標準。 |
| Standard deviation (σ) | 標準偏差（σ） |
A statistical term used to quantify the Scatter in a set of data points. If the standard deviation is small, most of the data points are ‘‘nearly equal.’’ A large deviation means less agreement. The most usual measure of the dispersion of observed values or results expressed as the positive square root of the variance. The square root of variance, a measure of the spread of data about the mean value. 用于量化一組數據點中分散度的統計術語。如果標準偏差很小，則大多數數據點“幾乎相等”大的偏差意味著更少的一致性。觀測值或結果離散度的最常用度量，表示為方差的正平方根。方差的平方根，衡量平均值的數據分布。 |
| Standard fit | 標準匹配 |
The fit of a component machined or otherwise manufactured to standardized clearances and tolerances. 根據標準間隙和公差加工或以其他方式制造的部件的配合。 |
| Standard gauge | 標準量規 |
A highly-accurate reference gauge against which to check working gauges. 一種高精度的基準量規，用于檢查工作量規。 |
| Standard hole | 標準孔 |
A hole in a workpiece bored to a specified tolerance where clearance with a shaft is accomplished by allowance on the shaft. A standard shaft is machined to a specified tolerance where clearance with a hole is accomplished by allowance on the hole. 工件上的孔，鉆孔至規定公差，其中與軸的間隙通過軸上的余量來實現。標準軸加工至規定公差，其中與孔的間隙通過孔上的公差實現。 |
| Standardization | 標準化 |
1. National and international agreements for design, manufacture, materials, performance, practices, requirements, strength, etc. which ensure common results wherever an item is made and wherever used. 2. The manufacture of components so that interchangeability of parts during assembly of new, or repair of old, items is possible without ‘fitting’. 1.關于設計、制造、材料、性能、慣例、要求、強度等的國家和國際協議，確保在任何地方制造和使用物品都能產生共同結果。2.部件的制造，以便在裝配新部件或維修舊部件時，無需“裝配”即可實現部件的互換性。 |
| Starting friction | 起動摩擦 |
(limiting friction, static friction, stiction) (Unit N) The force required to initiate movement between two bodies in contact. （極限摩擦力、靜摩擦力、粘滯）（單位N）在兩個接觸物體之間啟動運動所需的力。 |
| Starting taper | 起始錐度 |
The taper on the end of a reamer or tap which aids in starting the cut. 鉸刀或絲錐端部的錐度，有助于開始切割。 |
| Starting torque (Unit N.m) | 起動扭矩（單位：N.m） |
The torque developed by a motor at zero rotational speed in order to initiate rotation of the applied load. 電機在零轉速下產生的扭矩，以啟動所施加負載的旋轉。 |
| Starting valve (regulator) | 起動閥（調節器） |
A valve which admits steam from the boiler to the cylinder(s) of a steam engine. 將蒸汽從鍋爐送入蒸汽機汽缸的閥門。 |
| Static equilibrium | 靜態平衡 |
A solid body, structure, or physical system (or any subdivided part) will be in static equilibrium, either at rest or moving with constant velocity, if the resultants of all external forces and moments acting on it are zero. 如果作用在固體上的所有外力和力矩的合力為零，則固體、結構或物理系統（或任何細分部分）無論是靜止還是以恒定速度移動，都是處于靜態平衡。 |
| Static fatigue | 靜態疲勞 |
A term referring to a time-dependent reduction in strength with a static (noncyclic) load. The term may refer to hydrogen-induced delayed cracking or the effect of creep on the strength of plastics. Delayed fracture caused by environmental effects under dead-weight loading of materials such as glass. The name is unfortunate, as cyclic loads are not involved and glass is not susceptible to fatigue. 指靜態（非循環）載荷下強度隨時間變化的降低。該術語可指氫致延遲開裂或蠕變對塑料強度的影響。在玻璃等材料的自重荷載下，由環境影響引起的延遲斷裂。 |
| Statistic | 統計 |
A summary value calculated from the observed values in a sample. 根據樣本中的觀察值計算得出的匯總值。 |
| Stator | 定子 |
A ring of non-rotating blades or nozzles in a compressor, turbine, or other turbomachine, which directs fluid flow into an adjacent rotor. 渦輪壓縮機、渦輪或其他渦輪機械中的一圈不旋轉的葉片或噴嘴，將流體引導到相鄰的轉子中。 |
| Steady loads | 穩定負載 |
Loads that do not change in intensity or that change so slowly they may be regarded as steady. 強度不變或變化緩慢的荷載可視為穩定荷載。 |
| Steady pin | 定位銷 |
A dowel, key, or pin that prevents a pulley from turning on its shaft. 防止滑輪在其軸上轉動的銷釘、鍵或銷。 |
| Stead’s brittleness | 斯特德脆性 |
A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling. 一種脆性狀態，導致粗晶結構中發生穿晶斷裂，這是由于之前在低于約705°C（1300°F）的溫度下軋制的低碳鋼薄板經過長時間退火造成的。斷裂通常發生在與軋制方向約45°處。 |
| Steam gauge | 汽壓表 |
A pressure gauge used to measure gauge pressure in a line, boiler, cylinder, or other device operating with steam. 一種壓力表，用于測量管道、鍋爐、汽缸或其他與蒸汽一起工作的裝置中的表壓。 |
| Steel-wire rope | 鋼絲繩 |
A rope or cable made up of many steel strands wrapped helically about an axis, each strand being made of metal wires twisted together like a helix. 一種繩索或纜繩，由許多繞軸螺旋纏繞的鋼絞線組成，每根鋼絞線由金屬絲纏繞在一起形成螺旋。 |
| Stiffness | 剛度 |
(1) The ability of a metal or shape to resist elastic deflection.(2) The rate of stress increase with respect to the rate of increase in strain induced in the metal or shape; the greater the stress required to produce a given strain, the stiffer the material is said to be. （1）金屬或形狀抵抗彈性變形的能力。（2）所述應力增加速率相對于在所述金屬或形狀中誘導的應變增加速率；產生給定應變所需的應力越大，材料就越硬。 |
| Stove bolt | 爐用螺栓 |
This bolt has been so named because of its use in stove building. It is made in a number of different forms, either with a round button, or flat countersunk head, the head having a slot for a screwdriver and the threaded end being provided with a square or hexagon nut. 這種螺栓因其在爐灶建筑中的用途而得名。它有多種不同的形式，有圓形按鈕或平沉頭，頭部有螺絲刀槽，螺紋端有方形或六角螺母。 |
| Strain | 拉緊 |
The unit of change in the size or shape of a body due to force. Also known as nominal strain. 物體的大小或形狀因力而變化的單位。也稱為標稱應變。 |
| Strain aging | 應變時效 |
The changes in ductility, hardness, yield point, and tensile strength that occur when a metal or alloy that has been cold worked is stored for some time. In steel, strain aging is characterized by a loss of ductility and a corresponding increase in hardness, yield point, and tensile strength. 已冷加工的金屬或合金在儲存一段時間后發生的延展性、硬度、屈服點和抗拉強度的變化。在鋼中，應變時效的特點是延性損失，硬度、屈服點和抗拉強度相應增加。 |
| Strain energy | 應變能 |
A measure of the energy absorption characteristics of a material determined by measuring the area under the stress-strain diagram. 通過測量應力-應變圖下的面積確定的材料能量吸收特性的度量。 |
| Strain gage | 應變計 |
A device for measuring small amounts of strain produced during tensile and similar tests on metal. A coil of fine wire is mounted on a piece of paper, plastic, or similar carrier matrix (backing material), which is rectangular in shape and usually about 25 mm (1.0 in.) long. This is glued to a portion of metal under test. As the coil extends with the specimen, its electrical resistance increases in direct proportion. This is known as bonded resistance-strain gage. Other types of gages measure the actual deformation. Mechanical, optical, or electronic devices are sometimes used to magnify the strain for easier reading. 一種測量金屬拉伸和類似試驗中產生的少量應變的裝置。將一卷細線安裝在一張紙、塑料或類似載體基質（背襯材料）上，該載體基質呈矩形，通常約25mm（1.0in.）長，這是粘在測試金屬的一部分。隨著線圈隨試樣延伸，其電阻成正比增加，這被稱為粘結電阻應變計。其他類型的量規測量實際變形。機械、光學或電子設備有時用于放大應變以便于讀取。 |
| Strain hardening | 應變硬化 |
An increase in hardness and strengthcaused by plastic deformation at temperatures below the recrystallization range. Also known as work hardening. (workhardening) The increase in stress above the initial yield stress required to deform a metal to greater strains in the plastic range at temperatures below the recrystallization range (cold working). Unloading after some strain or work input gives a harder and stronger material. 在低于再結晶范圍的溫度下，塑性變形導致硬度和強度的增加。也稱為加工硬化。（加工硬化）在低于再結晶范圍（冷加工）的溫度下，使金屬在塑性范圍內變形至更大應變所需的高于初始屈服應力的應力增加。在一定的應變或功輸入后卸載，會得到更硬、更強的材料。 |
| Strain rate | 應變率 |
The time rate of straining for the usual tensile test. Strain as measured directly on the specimen gage length is used for determining strain rate. Because strain is dimensionless, the units of strain rate are reciprocal time. 通常拉伸試驗的應變時間速率。直接在試樣標距上測量的應變用于確定應變率。因為應變是無因次的，所以應變率的單位是倒數時間。 |
| Strain-age embrittlement | 應變時效脆化 |
A loss in ductility accompanied by an increase in hardness and strength that occurs when low-carbon steel (especially rimmed or capped steel) is aged following plastic deformation. The degree of embrittlement is a function of aging time and temperature, occurring in a matter of minutes at about 200°C (400 °F), but requiring a few hours to a year at room temperature. 塑性變形后低碳鋼（尤其是邊緣鋼或封頂鋼）時效時發生的延展性損失，伴隨著硬度和強度的增加。脆化程度是老化時間和溫度的函數，在大約200°C（400°F）的溫度下，在幾分鐘內發生，但在室溫下需要幾小時到一年。 |
| Strain-hardening exponent (n value) | 應變硬化指數（n值） |
The value n in the relationship σ = Kεn, where σ is the true stress, ε is the true strain, and K, the strength coefficient, is equal to the true stress at a true strain of 1.0. The strain hardening exponent is equal to the slope of the true stress/true strain curve up to maximum load, when plotted on log-log coordinates. The n-value relates to the ability of a sheet of material to be stretched in metalworking operations. The higher the n-value, the better the formability(stretchability). Also known as the strain-hardening coefficient. 關系式σ=Kεn中的值n，其中σ是真應力，ε是真應變，K是強度系數，等于真應變為1.0時的真應力。在對數坐標上繪制時，應變硬化指數等于真應力/真應變曲線的斜率，直到最大載荷。n值與一片材料在金屬加工操作中拉伸的能力有關。n值越高，成形性（拉伸性）越好。也稱為應變硬化系數。 |
| Strength (Unit Pa) | 強度（單位Pa） |
The maximum stress, in tension, compression, shear, or combinations thereof, that may be monotonically applied to a material, component, or structure before failure (defined as fracture, yielding, buckling, etc. as appropriate). 在破壞前（視情況定義為斷裂、屈服、屈曲等），材料、部件或結構在拉伸、壓縮、剪切或其組合中可能單調施加的最大應力。 |
| Strength of bolt | 螺栓強度 |
An ambiguous term which can mean Ultimate strength or Proof load or Endurance limit or Yield strength. 一個模棱兩可的術語，可表示極限強度或驗證荷載或耐久極限或屈服強度。 |
| Strength of materials | 材料強度 |
A confusing name for what is really stress analysis, reflecting older engineering design based upon elasticity and ‘theories of strength’ for different materials, without regard to cracks. 對于真正的應力分析，這是一個具有迷惑性的名稱，反映了基于彈性和不同材料的“強度理論”的舊工程設計，而不考慮斷裂。 |
| Stress | 應力（單位Pa） |
The intensity of the internally distributed forces or components of forces that resist a change in the volume or shape of a material that is or has been subjected to external forces. Stress is expressed in force per unit area and is calculated on the basis of the original dimensions of the cross section of the specimen. Stress can be either direct (tension or compression)or shear. 1. Stress ‘at a point’ (i.e. over a volume of material that is very small compared with that of the component or structure) is the load per unit area for every face of an infinitesimal cube surrounding the point. 2. In fluid flow the stress tensor σij is the sum of an isotropic part ?pδij, δij being the Kronecker delta, having the same form as the stress tensor for a fluid at rest, p being the static pressure, and the non-isotropic, deviatoric stress tensor dij which is due entirely to the fluid motion. 內部分布力或力分量的強度，這些力或力的分量抵抗正在或已經受到外力的材料的體積或形狀的變化。應力以單位面積的力表示，并根據試樣橫截面的原始尺寸計算。應力可以是直接（拉伸或壓縮）或剪切。1.“在一點”的應力（即在與組件或結構相比非常小的材料體積上）是圍繞該點的無限小立方體的每個面的單位面積載荷。2. 在流體流動中，應力張量σij是各向同性部分-pδij的總和，δij是Kroneckerδ，具有與靜止流體的應力張量相同的形式，p是靜壓，非各向同性, 偏應力張量 dij 完全由流體運動引起。 |
| Stress amplitude | 應力幅值 |
One-half the algebraic difference between the maximum and minimum stress in one cycle of a repetitively varying stress. 重復變化應力的一個循環中最大和最小應力之間代數差的一半。 |
| Stress area | 應力面積 |
The effective cross-sectional area of the threaded section of a fastener. Used to compute average stress levels in that section. Based on the mean of pitch and minor diameters. 緊固件螺紋部分的有效橫截面積。用于計算該截面中的平均應力水平。基于節距和小直徑的平均值。 |
| Stress corrosion | 應力腐蝕 |
(stress-corrosion cracking) Corrosion failure accelerated by local stresses (particularly tensile) which enhance cracking in both monotonic and fatigue loading. （應力腐蝕開裂）局部應力（特別是拉伸應力）加速的腐蝕失效，該局部應力在單調載荷和疲勞載荷下都會增強開裂。 |
| Stress corrosion cracking (SCC) | 應力腐蝕開裂（SCC） |
A common form of Stress cracking in which an Electrolyte encourages the growth of a crack in a highly stressed bolt. Only a tiny quantity of electrolyte need be present, at the tip or face of the crack. A time-dependent process in which a metallurgically susceptible material fractures prematurely under conditions of simultaneous corrosion and sustained loading at lower stress levels than would be required in the absence of a corrosive environment. Tensile stress is required at the metal surface and may be a residual stress resulting from heat treatment or fabrication of the metal or the result of external loading. Cracking may be intergranular or transgranular, depending on the combination of alloy and environment. 一種常見的應力開裂形式，其中電解液促使高應力螺栓中的裂紋擴展。在裂紋尖端或表面，只需存在少量電解質。一種隨時間變化的過程，其中冶金敏感材料在同時腐蝕和持續加載的條件下過早斷裂，其應力水平低于無腐蝕環境時的要求。在金屬表面需要拉應力，拉應力可以是金屬的熱處理或制造或外部負載產生的殘余應力。裂紋可能是沿晶開裂或穿晶開裂，這取決于合金和環境的組合。 |
| Stress cracking | 應力開裂 |
A family of failure modes, each of which involves high stress and chemical action. The family includes Hydrogen embrittlement, Stress corrosion cracking, stress embrittlement, and hydrogen-assisted stress corrosion. 一系列失效模式，每種模式都涉及高應力和化學作用。該系列包括氫脆、應力腐蝕開裂、應力脆化和氫輔助應力腐蝕。 |
| Stress cycle | 應力循環 |
The smallest segment of the stress-time function that is repeated periodically. 周期性重復的應力時間函數的最小段。 |
| Stress cycles endured (N) | 承受的應力循環（N） |
The number of cycles of a specified character (that produce fluctuating stress and strain) that a specimen has endured at any time in its stress history. 試樣在其應力歷史中任何時間所經受的特定特征（產生波動應力和應變）的循環次數。 |
| Stress difference (Unit Pa) | 應力差（單位Pa） |
The algebraic difference between the largest and least principal stresses in a loaded body, equal to twice the greatest shear stress in the system. For σ1 > σ2 > σ3, it is given by (σ1 ? σ3). 載荷體中最大和最小主應力之間的代數差，等于系統中最大剪應力的兩倍。由（σ1? σ3).，可得σ1＞σ2＞σ3。 |
| Stress distribution | 應力分布 |
The manner in which tensile, compressive, and shear stresses are distributed within a loaded body, indicated by loci of constant stress. 拉應力、壓應力和剪應力在受載物體內的分布方式，由恒定應力軌跡表示。 |
| Stress equalizing | 應力均衡 |
A low-temperature heat treatment used to balance stresses in cold-worked material without an appreciable decrease in the mechanical strength produced by cold working. 一種低溫熱處理，用于平衡冷加工材料中的應力，而不會明顯降低冷加工產生的機械強度。 |
| Stress factor | 應力因子 |
A calibration constant used in ultrasonic measurement of bolt stress or strain. It is the ratio between the change in ultrasonic transit time caused by the change in length of the fastener, under load, to the total change in transit time. 用于螺栓應力或應變超聲波測量的校準常數。它是由緊固件長度變化引起的超聲波傳輸時間變化與總傳輸時間變化之間的比率。 |
| Stress raisers | 局部應力集中 |
Changes in contour or discontinuities in structure that cause local increases in stress. 導致局部應力增加的輪廓變化或結構不連續性變化。 |
| Stress ratio (A or R) | 應力比（A或R） |
The algebraic ratio of two specified stress values in a stress cycle. Two commonly used stress ratios are the ratio of the alternating stress amplitude to the mean stress, A = Sa/Sm, and the ratio of the minimum stress to the maximum stress, R = Smin/Smax. 應力循環中兩個指定應力值的代數比。兩種常用的應力比是交變應力振幅與平均應力之比，A=Sa/Sm，以及最小應力與最大應力之比R=Smin/Smax。 |
| Stress relaxation | 應力松弛 |
The slow decrease in stress level within a part (e.g., a bolt) which is heavily loaded under constant deflection conditions. A ‘‘cousin’’ to creep, which is a slow change in geometry under constant stress conditions. The time-dependent decrease in stress in a solid under constant strain at constant temperature due to creep. The stress-relaxation behavior of a metal is usually shown in a stress-relaxation curve. 在恒定撓曲條件下，零件（如螺栓）內的應力水平緩慢降低，該零件承受重荷載。蠕變的“表親”，是在恒定應力條件下幾何結構的緩慢變化。在恒定溫度下，由于蠕變，固體在恒定應變下的應力隨時間變化的減小。金屬的應力松弛行為通常顯示在應力松弛曲線中。 |
| Stress relieving | 應力消除 |
Heating to a suitable temperature, holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses. 加熱到合適的溫度，保持足夠長的時間以減少殘余應力，然后緩慢冷卻以盡量減少新殘余應力的產生。 |
| Stress wave | 應力波 |
An unbalanced force, such as an impact, applied at one location in a body sets the material there into vibration that is transmitted to adjacent elements and ultimately to all parts of the body in the form of stress waves or wave packets. 施加在物體某個位置的不平衡力（如沖擊力）會使物體中的材料產生振動，并以應力波或波包的形式傳遞到相鄰元件，最終傳遞到物體的所有部位。 |
| Stress-concentration factor (Kt) | 應力集中系數（Kt） |
A multiplying factor for applied stress that allows for the presence of a structural discontinuity such as a notch or hole; Kt?equals the ratio of the greatest stress in the region of the discontinuity to the nominal stress for the entire section. Also known as theoretical stress-concentration factor. 施加應力的倍增系數，允許存在結構不連續性，如缺口或孔；Kt等于不連續區域的最大應力與整個截面的標稱應力之比。也稱為理論應力集中系數。 |
| Stress-intensity calibration | 應力強度校準 |
A mathematical expression, based on empirical or analytical results, that relates the stress-intensity factor to load and crack length for a specific specimen planar geometry. Also known as Kcalibration. 基于經驗或分析結果的數學表達式，該表達式將特定試樣平面幾何形狀的應力強度因子與載荷和裂紋長度聯系起來。也稱為K校準。 |
| Stress-intensity factor | 應力強度因子 |
A scaling factor, usually denoted by the symbol K, used in linear-elastic fracture mechanics to describe the intensification of applied stress at the tip of a crack of known size and shape. At the onset of rapid crack propagation in any structure containing a crack, the factor is called the critical stress-intensity factor, or the fracture toughness. 一種標度因子，通常用符號K表示，在線彈性斷裂力學中用于描述已知尺寸和形狀的裂紋尖端施加應力的增強。在任何含有裂紋的結構中，裂紋快速擴展開始時，該因子稱為臨界應力強度因子，或斷裂韌性。 |
| Stress-relaxation curve | 應力松弛曲線 |
A plot of the remaining, or relaxed, stress in a stress-relaxation test as a function of time. The relaxed stress equals the initial stress minus the remaining stress. Also known as a stress-time curve. 應力松弛試驗中剩余應力或松弛應力隨時間變化的曲線圖。松弛應力等于初始應力減去剩余應力。也稱為應力-時間曲線。 |
| Stress-strain diagram | 應力-應變圖 |
A graph in which corresponding values of stress and strain are plotted against each other. Values of stress are usually plotted vertically(ordinates or y-axis) and values of strain horizontally (abscissas or xaxis). Also known as deformation curve and stress-strain curve. 對應的應力和應變值相對繪制的圖表。應力值通常垂直繪制（縱坐標或y軸），應變值水平繪制（橫坐標或X軸）。也稱為變形曲線和應力-應變曲線。 |
| Stress–strain curve | 應力-應變曲線 |
(stress–strain diagram) A plot of stress vs strain for a solid material obtained from a test in which a specimen is loaded in tension, compression, shear, or combinations thereof. Diagrams of true stress vs true strain deviate from those of nominal stress vs nominal strain only at large strains where appreciable changes in cross section of testpieces occur. （應力-應變圖）從試驗中獲得的固體材料的應力與應變圖，其中試樣在拉伸、壓縮、剪切或其組合中加載。只有在試件橫截面發生明顯變化的大應變下，真實應力與真實應變圖與標稱應力與標稱應變圖不同。 |
| Stretch forming | 拉伸成型 |
A manufacturing process in which sheet-metal components are physically stretched over a forming die using a press, punch, or edge clamps. Stretching combined with bending reduces springback. 一種制造工藝，其中使用壓力機、沖頭或邊緣夾具在成形模上物理拉伸金屬板部件。拉伸與彎曲相結合可減少回彈。 |
| Stretch ratio (extension ratio, λ) | 拉伸比（拉伸比，λ） |
A measure, used for highly-extensible materials such as rubber, of the extensional or normal strain of a component subjected to tension and defined as the ratio of the final length l, for a given load, to the initial or gauge length l0, where the coordinate axes are those of principal strain. It is related to the engineering strain e by λ = 1 + e. 用于高度可延展材料（如橡膠）的一種測量方法，用于測量受拉構件的拉伸或法向應變，定義為給定載荷下的最終長度l與初始或標距長度l0之比，其中坐標軸為主應變軸。它與工程應變e的關系為λ=1+e。 |
| Stretch-bending test | 拉伸彎曲試驗 |
A simulative test for sheet metal formability in which a strip of sheet metal is clamped at its ends in lock beads and deformed in the center by a punch. Test conditions are chosen so that fracture occurs in the region of punch contact. 金屬板成形性的模擬試驗，其中金屬板條在其端部夾緊在鎖珠中，并通過沖頭在中心變形。選擇試驗條件，以便在沖頭接觸區域發生斷裂。 |
| Striation | 條紋組織 |
A fatigue fracture feature, often observed in electron micrographs, that indicates the position of the crack front after each succeeding cycle of stress. The distance between striations indicates the advance of the crack front across that crystal during one stress cycle, and a line normal to the striation indicates the direction of local crack propagation. 一種疲勞斷裂特征，通常在電子顯微照片中觀察到，表明每次應力循環后裂紋前沿的位置。條紋之間的距離表示在一個應力循環期間裂紋前沿穿過該晶體的前進，垂直于條紋的線表示局部裂紋擴展的方向。 |
| Stroke | 一擊 |
1. (stroke length) (Unit m) The linear distance between top dead centre and bottom dead centre of a piston in a reciprocating engine or mechanism. 2. The movement of a piston or plunger in a reciprocating machine to execute a particular function; for example, the exhaust stroke of an engine in which the exhaust gases are expelled from a cylinder. 1.（沖程長度）（單位：m）往復式發動機或機構中活塞上止點和下止點之間的線性距離。2.活塞或柱塞在往復式機器中執行特定功能的運動；例如發動機的排氣沖程，其中排氣從氣缸中排出。 |
| Structural analysis | 結構分析 |
The determination of the forces, displacements, stresses, and strains in a given structure. 確定給定結構中的力、位移、應力和應變。 |
| Structural engineering | 結構工程 |
A branch of civil engineering concerned with the design of buildings, dams, bridges, and other large structures. 土木工程的一個分支，涉及建筑物、水壩、橋梁和其他大型結構的設計。 |
| Structural frame | 結構框架 |
The underlying load-bearing framework of beams, columns, bracing, etc., of steel, concrete, brick, stone, timber etc., required to support the static and dynamic forces a building or component is subjected to, including its weight and that of its contents. 由鋼、混凝土、磚、石、木材等制成的梁、柱、支撐等構成的底層承重框架，用于支撐建筑物或構件承受的靜態和動態力，包括其重量及其內含物的重量。 |
| Structural-integrity analysis | 結構完整性分析 |
Assessment of components and structures for likelihood of failure by buckling, fracture, yielding, etc. under conditions of normal and accident loading. 在正常和事故荷載條件下，評估部件和結構因屈曲、斷裂、屈服等而失效的可能性。 |
| Structure | 結構體 |
An assembly, usually load bearing, of connected (pinned, riveted, screwed, bolted, welded, etc.) components, such as bars, tubes, beams, and plates. 由連接（銷接、鉚接、螺紋連接、螺栓連接、焊接等）部件組成的組件，通常為承重組件，如桿、管、梁和板。 |
| Stud | 螺柱 |
A rod having thread on both ends. A headless threaded fastener, threaded on both ends, with an unthreaded body in the middle section, or threaded from end to end. Used with two nuts, or with one nut and a tapped hole. A plain cylindrical piece having a threaded portion of suitable length at each end or a continuous thread over the entire length. One end is screwed into a machine or workpiece after which a second part is placed over the stud and held in place by a nut. 兩端都有螺紋的桿。無頭螺紋緊固件，兩端有螺紋，中間部分有無螺紋主體，或從一端到另一端有螺紋。與兩個螺母或一個螺母和一個螺紋孔一起使用。一種普通的圓柱形部件，其兩端具有適當長度的螺紋部分，或在整個長度上具有連續螺紋。一端擰入機器或工件，然后將第二部分放在螺柱上，并用螺母固定到位。 |
| Subcritical annealing | 不完全退火 |
A process anneal performed on ferrous alloys at a temperature below Ac1. 在低于Ac1的溫度下對鐵合金進行的工藝退火。 |
| Submerged-electrode furnace | 浸入式電極爐 |
A furnace used for liquid carburizing of parts by heating molten salt baths with the use of electrodes submerged in the ceramic lining. 一種通過使用浸入陶瓷襯里中的電極加熱熔融鹽浴對零件進行液體滲碳的爐。 |
| Supercharging | 增壓 |
The process of increasing the mass flow rate of air (or air/fuel mixture) into the cylinder(s) of a piston engine using a compressor driven from the crankshaft (the supercharger). The power output is increased compared with a naturally-aspirated engine of the same capacity. The process also increases the air pressure and density to greater than ambient. In the past, most superchargers were mechanically driven from the engine’s crankshaft, but these have been largely superseded by turbochargers. 使用由曲軸（增壓器）驅動的壓縮機增加進入活塞式發動機氣缸的空氣（或空氣/燃料混合物）質量流率的過程。與相同容量的自然吸氣發動機相比，功率輸出增加。該過程還將空氣壓力和密度增加到大于環境壓力和密度。在過去，大多數增壓器都是由發動機曲軸機械驅動的，但這些增壓器在很大程度上已被渦輪增壓器所取代。 |
| Supercooling | 過冷 |
Cooling below the temperature at which an equilibrium phase transformation can take place, without actually obtaining the transformation. 在沒有實際獲得相變的情況下，冷卻到可以發生平衡相變的溫度以下。 |
| Superheating | 過熱 |
Heating above the temperature at which an equilibrium phase transformation should occur without actually obtaining the transformation. 在不實際獲得相變的情況下，加熱到應發生平衡相變的溫度以上。 |
| Surface hardening | 表面硬化 |
A generic term covering several processes applicable to a suitable ferrous alloy that produces, by quench hardening only, a surface layer that is harder or more wear resistant than the core. There is no significant alteration of the chemical composition of the surface layer. The processes commonly used are carbonitriding, carburizing, induction hardening, flame hardening, nitriding, and nitrocarburizing. Use of the applicable specific process name is preferred. 一個通用術語，涵蓋適用于僅通過淬火硬化產生比型芯更硬或更耐磨的表面層的合適鐵合金的幾種工藝。表面層的化學成分沒有顯著改變。常用的工藝有碳氮共滲、滲碳、感應淬火、火焰淬火、氮化和氮碳共滲。最好使用適用的特定工藝名稱。 |
| Surface hardness | 表面硬度 |
(superficial hardness) Indentation hardness on, and for some distance below, the surface of a component, as opposed to its bulk hardness. Depending on the resolution required, micro- or nano-hardness testing machines are employed. （表面硬度）與整體硬度相反，部件表面及其下方一定距離的壓痕硬度。根據所需的分辨率，可使用微型或納米硬度測試機。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固體表面中的小尺度不規則峰谷，使用表面分析儀進行量化。粗糙度可能是磨損和腐蝕或制造過程的結果。它會導致表面上的固-固接觸或流體流動中的摩擦增加。不包括形狀和波紋度誤差，但表面紋理包括粗糙度和波紋度。表面形貌包括表面的小尺度三維幾何結構，包括表面粗糙度、機加工和蝕刻特征，通常為亞毫米尺度。 |
| Surface tension (σ, γ) (Unit N/m) | 表面張力（σ，γ）（單位：N/m） |
At the interface between a liquid and a gas or two immiscible liquids, unbalanced cohesive forces acting on the liquid molecules at the interface lead to the property surface tension which causes tensile forces to develop as if it were a skin or membrane. 液體和氣體或兩種不混溶液體之間的界面處，作用在界面處的液體分子上的不平衡內聚力導致表面張力的性質，從而導致張力的發展，就像皮膚或薄膜一樣。 |
| Surface treatment | 表面處理 |
Any process, including chemical, electrochemical, mechanical, and thermal, designed to protect a surface against corrosion and wear or to alter its mechanical properties. 任何旨在保護表面免受腐蝕和磨損或改變其機械性能的工藝，包括化學、電化學、機械和熱處理。 |
| Swept volume (Unit m3) | 掃描體（單位m3) |
In the cylinder of a piston engine or other device, the volume between top and bottom dead centre positions of a piston; equal to πR2S where R is the piston radius and S is the stroke. 在活塞發動機或其他裝置的氣缸中，活塞上止點和下止點位置之間的體積；等于πR2S，其中R是活塞半徑，S是沖程。 |
| Swift cup test | 斯威夫特杯測試 |
A simulative cupping test in which circular blanks of various diameters are clamped in a die ring and deep drawn into cups by a flat-bottomed cylindrical punch. 一種模擬拔杯試驗，將不同直徑的圓形坯料夾緊在模環中，并用平底圓柱沖頭將其深拉入杯中。 |
| System engineering | 系統工程 |
A methodology which integrates all disciplines and specialty groups into a team effort, forming a structured development process that proceeds from concept to production to operation. 一種將所有學科和專業組整合到團隊工作中的方法，形成從概念到生產再到運營的結構化開發過程。 |