| 詞或詞組 | 中文 | 英文解釋中文解釋 |
|---|---|---|
| Damage | 損傷 |
1. The deterioration of a component or structure in fault or accident conditions, reducing or preventing its ability to perform its intended function. 2. The accumulation of defects or microcracks in the microstructure of a body loaded monotonically or in fatigue, which weakens the body and can lead to crack propagation and failure. 1.部件或結構在故障或事故條件下的劣化，降低或阻止其執行預期功能的能力。2.在承受單調載荷或疲勞載荷的物體的微觀結構中累積的缺陷或微裂紋，這會削弱物體，并可能導致裂紋擴展和失效。 |
| Damage mechanics | 損傷機制 |
The theory of degradation in bodies, particularly fracture by accumulated microstructural damage. Analyses take two approaches: (a) the use of some critical integrated function of stress and strain at which cracking is initiated and propagated; (b) incorporation of damage in the stress–strain curves to reflect weakened material. 物體退化理論，尤其是累積微觀結構損傷導致的斷裂。分析采用兩種方法：（a）使用裂紋開始和擴展時的應力和應變的一些臨界積分函數；（b）應力-應變曲線中包含損傷，以反映弱化材料。 |
| Damage tolerance | 損傷容限 |
(defect tolerance) A design philosophy that takes into account initial imperfections, crack-growth rates and conditions at final fracture, and uses fracture mechanics to demonstrate that cracks should not grow to their critical length within the design life (or at least should be capable of ready detection). （缺陷公差）考慮初始缺陷、裂紋擴展速率和最終斷裂條件的設計理念，并使用斷裂力學證明裂紋不應在設計壽命內增長到其臨界長度（或至少應能夠隨時檢測）。 |
| Dead centre | 止點 |
The point at which, in a crank mechanism, the piston connecting rod and crank are all in line so that there can be no driving moment. 在曲柄機構中，活塞連桿和曲柄都在一條線上，因此不會有驅動力矩。 |
| Dead load (Unit N) | 靜載（單位N） |
A load on a component or structure that is steady with time, e.g. the self-weight of a bridge. 部件或結構上隨時間穩定的載荷，例如橋梁的自重。 |
| Dead space | 死區 |
(dead volume) (Unit m3) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（單位m3）充氣溫度計的體積，其中氣體的溫度與被測溫度不同。 |
| Decalescence | 退色 |
A phenomenon, associated with the transformation of alpha iron to gamma iron on the heating (superheating) of iron or steel, revealed by the darkening of the metal surface owing to the sudden decrease in temperature caused by the fast absorption of the latent heat of transformation. 一種現象，與鐵或鋼加熱（過熱）時α鐵向γ鐵的轉變有關，由于轉變潛熱的快速吸收導致溫度突然降低，金屬表面變黑。 |
| Decarburization | 脫碳 |
Loss of carbon from the surface layer of a carbon-containing alloy due to reaction with one or more chemical substances in a medium that contacts the surface. 由于與接觸表面的介質中的一種或多種化學物質發生反應，含碳合金表面層的碳損失。 |
| Decompression chamber | 減壓艙 |
A chamber in which ambient-air pressure can be increased to levels found in deep-sea diving. It is used to gradually acclimatize divers back to normal conditions and avoid ‘the bends’. 環境氣壓可以提高到深海潛水水平的腔室。它用于逐漸使潛水員適應正常條件，避免“彎曲”。 |
| Deflection temperature under load (DTUL) | 負載變形溫度（DTUL） |
The temperature at which a simple cantilever beam deflects a given amount under load. Formerly called heat distortion temperature. 簡單懸臂梁在負載下偏轉給定量的溫度。以前稱為熱變形溫度。 |
| Deformation (Unit 1/s) | 變形（單位1/s） |
A change in the form of a body due to stress, thermal change, change in moisture, or other causes. In solid mechanics, any change, reversible (elastic) or permanent (plastic), in the shape or size of parts of a body, or the whole body, caused by external or internal loading. It includes extension, compression, bending, and twisting. The same state of deformation in a body can appear as different combinations of elongation and shear. To state how much of the total strain is shear, it is split into dilatation and deviatoric components, the former changing volume but not shape, the latter shape but not volume. 由于壓力、熱變化、水分變化或其他原因導致的身體形態變化。在固體力學中，由外部或內部載荷引起的身體各部分或整個身體的形狀或大小的任何可逆（彈性）或永久（塑性）變化。它包括拉伸、壓縮、彎曲和扭曲。物體中相同的變形狀態可以表現為伸長和剪切的不同組合。為了說明總應變中有多少是剪切，將其分為膨脹分量和偏差分量，前者改變體積但不改變形狀，后者改變形狀但不改變體積。 |
| Degradation | 降解 |
The reduction with time of the physical properties of a material. 材料的物理性質隨時間的減少。 |
| Degradation failure | 退化失效 |
Failure of a system, component, or structure owing to material degradation. 由于材料退化導致的系統、組件或結構失效。 |
| Degradation of energy | 能源退化 |
Conversion of energy into forms of lower usefulness due to irreversibilities in energy transfer and conversion processes. The increase in entropy can be regarded as a measure of the degradation of energy. 由于能量轉移和轉換過程中的不可逆性，將能量轉換為低效形式。熵的增加可以看作是能量退化的量度。 |
| Degree (°) | 度數（°） |
A measure of plane angle such that 1° is 1/360 of a complete revolution and equal to π/180 rad. 平面角度的一種度量，使得1°是一整圈的1/360，等于π/180弧度。 |
| Degrees of freedom | 自由度 |
The number of independent variables (such as temperature, pressure, or concentration within the phases present) that may be altered at will without causing a phase change in an alloy system at equilibrium; or the number of such variables that must be fixed arbitrarily to define the system completely. 可以隨意改變而不引起平衡時合金系統相變的自變量的數量（例如存在的相內的溫度、壓力或濃度）；或必須任意固定以完全定義系統的此類變量的數量。 |
| Delamination | 分層 |
A mode of failure of composite materials, including radial-ply tyres, in which the layers separate due to repeated cyclic loading, impact, or weak bonding. 復合材料的一種失效模式，包括子午線輪胎，其中層由于重復的循環載荷、沖擊或弱粘合而分離。 |
| Densimeter | 密度計 |
An instrument used to determine the density or relative density of a solid or liquid. 用于測定固體或液體的密度或相對密度的儀器。 |
| Density | 密度 |
The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m3) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume. 固體材料每單位體積的質量。（質量密度，ρ）（單位kg/m3）滿足連續統假設的物質每單位體積的質量。和比容相關聯。 |
| Deposit gauge | 沉積量計 |
(deposition gauge) An instrument employed in air pollution studies for measuring the amount of pollutant deposited on a given area in a given time under given conditions. （沉降計）在空氣污染研究中使用的儀器，用于測量在給定條件下在給定時間內沉積在給定區域上的污染物量。 |
| Depth (Unit m) | 深度（單位米） |
1. The vertical distance below a datum surface, especially the sea surface. 2. The distance between the top and bottom of a hole, step in a surface, or a container. 1.基準面以下的垂直距離，尤其是海面。2. 孔的頂部和底部之間的距離、表面上的臺階或容器中的距離。 |
| Depth gauge | 深度計 |
1. A precision instrument, typically consisting of a machine-divided steel rule passing through a hardened-steel cross head, used to measure the depths of slots, holes, shoulders, projections, etc. 2. A device used by divers to indicate the water depth. 1. 一種精密儀器，通常由穿過硬化鋼十字頭的機器分割鋼尺組成，用于測量槽、孔、肩部、突起等的深度。 2. 潛水員用來指示深度的裝置水深。 |
| Design code | 設計規范 |
(design standard) A standard or specification for any aspect of engineering design, issued by national organizations such as ANSI, ASME, BSI, DIN, and ISO. （設計標準）工程設計任何方面的標準或規范，由ANSI、ASME、BSI、DIN和ISO等國家組織發布。 |
| Design heating load (Unit kW) | 設計熱負荷（單位kW） |
The heating requirements based on a specified number of heating degree days, or required to maintain a building or other enclosed space at a specified temperature for a given outside temperature. 基于指定的采暖度日數的加熱要求，或在給定的外部溫度下將建筑物或其他封閉空間保持在指定溫度下所需的加熱要求。 |
| Design load (Unit N) | 設計荷載（單位N） |
The greatest load that a component or structure is expected to experience under normal operating conditions. 部件或結構在正常運行條件下預期承受的最大負載。 |
| Design pressure (Unit Pa) | 設計壓力（單位Pa） |
The greatest pressure that a closed container is expected to experience under normal operating conditions. 密閉容器在正常操作條件下預期承受的最大壓力。 |
| Design stress (Unit Pa) | 設計應力（單位Pa） |
The greatest allowable stress in a component or structure that will not result in failure under normal operating conditions. 在正常操作條件下不會導致失效的部件或結構中的最大許用應力。 |
| Destructive testing | 破壞性測試 |
Measurement of the mechanical properties of a material, component, or structure, by increased loading until the sample fails by fracture, collapse, or buckling. 通過增加載荷測量材料、部件或結構的機械性能，直到樣品因斷裂、塌陷或屈曲而失效。 |
| Deviation | 偏差 |
The difference between the actual value and the desired value of a controlled variable. 受控變量的實際值與期望值之間的差值。 |
| Dew point | 壓力露點 |
The temperature and pressure at which a gas begins to condense to a liquid. 氣體開始凝結成液體的溫度和壓力。 |
| Dew point analyzer | 露點分析儀 |
An atmosphere monitoring device that measures the partial pressure of water vapor in an atmosphere. 一種大氣監測裝置，用于測量大氣中水蒸氣的分壓。 |
| Diagonal pitch (Unit m) | 對角線間距（單位米） |
The distance, when components in an assembly are staggered, between the position of a component in one row or column and the position of the corresponding component in the next row or column. The term is applied to rivets, turbine or compressor blades in a cascade, vortex generators on the surface of a wing, etc. 當部件中的零部件交錯時，一行或一列中零部件的位置與下一行或下一列中相應零部件的位置之間的距離。該術語適用于鉚釘、葉柵中的渦輪或壓縮機葉片、機翼表面的渦流發生器等。 |
| Diaphragm compressor | 隔膜式壓縮機 |
A machine in which compression is achieved by the reciprocating motion of a flexible membrane of metal, plastic, or elastomeric material. This arrangement is ideally suited to pumping high-purity, toxic, or explosive gases. A similar machine incorporating check valves is a self-priming positive-displacement pump (diaphragm pump, membrane pump). 通過金屬、塑料或彈性材料的柔性薄膜的往復運動實現壓縮的機器。這種布置非常適合泵送高純度、有毒或爆炸性氣體。裝有止回閥的類似機器是自吸容積泵（隔膜泵、隔膜泵）。 |
| Diaphragm meter | 隔膜計 |
A dry flow meter in which there are two or more interconnected chambers, each having a diaphragm in the wall. The chambers empty and fill alternately and the flow rate of gas is determined from the movement of diaphragms. Diaphragm meters are commonly used to monitor domestic and commercial gas supply. 一種干式流量計，其中有兩個或多個相互連接的腔室，每個腔室的壁上都有一個隔膜。腔室交替排空和填充，氣體流速由隔膜的移動確定。隔膜流量計通常用于監測家用和商用燃氣供應。 |
| Die | 模具 |
1. A tool having an appropriately-shaped hole through which material may be extruded or drawn. 2. A tool employed in forging. 3. A block having the male or female shape employed in stamping operations. 4. A thick circular disc, driven by a die wrench, with internally-threaded cutting edges for producing a screw thread. A die wrench (die stock) holds a screw-cutting die and has two projecting arms for applying the torque necessary to cut the thread. A die having a hexagonal or square shape (die nut), driven by a spanner, is used in confined spaces where a die wrench cannot be rotated through a full circle. 1.一種具有適當形狀的孔的工具，通過該孔可以擠壓或拉伸材料。2.一種用于鍛造的工具。3.一種用于沖壓操作的具有陽或陰形狀的塊體。4.一種由模具扳手驅動的厚圓盤，具有用于產生螺紋的內螺紋切削刃。沖模扳手（沖模）裝有一個螺旋切割模，并有兩個突出臂，用于施加切割螺紋所需的扭矩。由扳手驅動的六邊形或方形模具（模具螺母）用于模具扳手無法旋轉一整圈的受限空間。 |
| Die casting | 壓鑄 |
A process in which molten metal, particularly alloys of aluminium, magnesium, copper, and zinc, is forced under pressure (10 to 200 MPa) into a reusable hardened-steel mould machined into a die. 在壓力（10至200MPa）下將熔融金屬（特別是鋁、鎂、銅和鋅的合金）強制進入加工成模具的可重復使用的硬化鋼模具中的過程。 |
| Die screw | 模具螺絲 |
Tool used when threading cylindrical pieces beyond the capacity of a die plate. 對超出模板容量的圓柱件進行螺紋加工時使用的工具。 |
| Die threading | 模具螺紋 |
Die threading is a machining process for cutting external threads in cylindrical or tapered surfaces by the use of solid or self-opening dies. Die threading is a slower method of producing external threads than thread rolling, but it is faster than single-point threading in a lathe. 模具螺紋加工是一種通過使用實心或自開模具在圓柱形或錐形表面上切削外螺紋的加工工藝。模具螺紋加工是一種比滾絲加工更慢的外螺紋加工方法，但它比車床中的單點螺紋加工要快。 |
| Diesel engine | 柴油發動機 |
(compression–ignition engine) A piston engine operating on the Diesel cycle in which the air is compressed to a temperature above the autoignition temperature of the fuel and combustion is initiated as the fuel is injected into the hot air. Diesel engines operate at higher compression ratios (typically in the range 12 to 24) than petrol engines. Although named after Rudolf Diesel, the inventor, Diesel engine is often spelled with a lower case d, contrary to normal practice. （壓燃式發動機）在柴油循環中運行的活塞式發動機，在該循環中，空氣被壓縮至高于燃料自燃溫度的溫度，當燃料噴射到熱空氣中時，燃燒開始。柴油發動機在比汽油發動機更高的壓縮比下運行（通常在12到24的范圍內）。雖然以發明人魯道夫·迪塞爾命名，但迪塞爾發動機通常拼寫為小寫d，這與正常做法相反。 |
| Differential heating | 差動加熱 |
Heating that intentionally produces a temperature gradient within an object such that, after cooling, a desired stress distribution or variation in properties is present within the object. 加熱有意在物體內產生溫度梯度，從而在冷卻后，在物體內出現所需的應力分布或特性變化。 |
| Diffusion | 擴散 |
(1) Spreading of a constituent in a gas, liquid, or solid, tending to make the composition of all parts uniform. (2) The spontaneous movement of atoms or molecules to new sites within a material. （1） 一種成分在氣體、液體或固體中的擴散，趨于使所有部分的成分均勻。（2） 原子或分子自發運動到材料內的新位置。 |
| Diffusion coating | 擴散涂層 |
Coating on metal for corrosion- and/or oxidation-resistance. Coatings are produced by heating a metal in contact with an alloy in powder, liquid, or gaseous form at elevated temperature such that atoms of the coating diffuse into the substrate. Examples include chromium, aluminium, or silicon on substrates such as nickel-based superalloys, steels, and refractory metals. 金屬上的防腐和/或抗氧化涂層。涂層是通過在高溫下加熱與粉末、液體或氣體形式的合金接觸的金屬，從而使涂層的原子擴散到基體中而產生的。實例包括基底上的鉻、鋁或硅，如鎳基高溫合金、鋼和耐火金屬。 |
| Diffusion coefficient | 擴散系數 |
A factor of proportionality representing the amount of substance diffusing across a unit area through a unit concentration gradient in unit time. 一個比例因子，表示在單位時間內通過單位濃度梯度擴散到單位面積上的物質量。 |
| Dilatation (dilation) | 膨脹 |
A change of volume caused by external load, compression, temperature change, chemical action, etc. 由外部載荷、壓縮、溫度變化、化學作用等引起的體積變化。 |
| Dilatometer | 膨脹計 |
An instrument for measuring length or volume changes in a solid during heating and subsequent cooling or isothermal holding. · An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature and allotropy. 一種在加熱和隨后的冷卻或等溫保持過程中測量固體長度或體積變化，測量金屬因溫度和同素異形體等因素的變化而引起的線性膨脹或收縮的儀器。 |
| Dimension line | 尺寸線 |
A line on an engineering drawing with a numeral above it that shows the length of a feature, usually in millimetres. 工程圖上的一條線，上面有一個數字，表示特征的長度，通常以毫米為單位。 |
| Dimensional stability | 尺寸穩定性 |
Ability of a plastic part to retain the precise shape in which it was molded, fabricated, or cast. 塑料零件保持其成型、制造或鑄造時的精確形狀的能力。 |
| Dimensioning | 尺寸標注 |
The specification on an engineering drawing of the size (e.g. length, radius, angle, or spacing) and the relative location (e.g. angular position) of each feature of a component. The numerical values often include the tolerances. There should be no more dimensions than are necessary to manufacture the component. 工程圖紙上對部件每個特征的尺寸（例如長度、半徑、角度或間距）和相對位置（例如角位置）的規范。數值通常包括公差。尺寸不應超過制造組件所需的尺寸。 |
| DIN | DIN |
Deutsches Institut für Normung, the German Institute for Standardization. Deutsches Institut für Normung，德國標準化研究所。 |
| Direct quenching | 直接淬火 |
(1) Quenching carburized parts directly from the carburizing operation. (2) Also used for quenching pearlitic malleable parts directly from the malleablizing operation. （1） 直接從滲碳作業中淬火滲碳零件。（2） 也用于直接從可鍛操作淬火珠光體可鍛零件。 |
| Dislocation density | 位錯密度 |
The total length of dislocation lines per unit volume, or the number of dislocation lines that cut through a unit cross-sectional area. 每單位體積的位錯線的總長度，或穿過單位橫截面積的位錯線的數量。 |
| Displacement | 移位 |
The distance that a chosen measurement point on a cracked specimen displaces normal to the crack plane as the crack grows. 隨著裂紋擴展，裂紋試樣上選定的測量點垂直于裂紋平面位移的距離。 |
| Distortion | 扭曲 |
Any deviation from an original size, shape, or contour that occurs because of the application of stress or the release of residual stress. 由于施加應力或釋放殘余應力而發生的與原始尺寸、形狀或輪廓的任何偏差。 |
| Double aging | 雙級時效 |
Employment of two different aging treatments to control the type of precipitate formed from a supersaturated matrix in order to obtain the desired properties. The first aging treatment, sometimes referred to as intermediate or stabilizing, is usually carried out at higher temperature than the second. 采用兩種不同的時效處理來控制由過飽和基質形成的沉淀物類型，以獲得所需的性能。第一次時效處理，有時稱為中間處理或穩定處理，通常在比第二次更高的溫度下進行。 |
| Double tempering | 雙回火 |
A treatment in which a quench-hardened ferrous metal is subjected to two complete tempering cycles, usually at substantially the same temperature, for the purpose of ensuring completion of the tempering reaction and promoting stability of the resulting microstructure. 一種處理，其中淬火硬化的黑色金屬經過兩個完整的回火循環，通常在基本相同的溫度下，以確保完成回火反應并提高所得微觀結構的穩定性。 |
| Double-shear test | 雙剪試驗 |
A shear test having two stationary, shear blades and one moving one and that uses solid round bars as test specimens. 一種剪切試驗，具有兩個固定的剪切刀片和一個移動的刀片，并使用實心圓棒作為試樣。 |
| Dowel | 銷釘 |
A headless cylindrical pin that fits into corresponding holes in mating components, thus ensuring relative location. A round metal or wooden pin. A pin, usually of circular shape like a cylinder, used to pin or fasten something in position temporarily or permanently. 一種圓頭金屬或木制圓柱銷，可插入配合組件的相應孔中，從而確保相對位置，用于暫時或永久地將某物固定或固定到位。 |
| Drift pin | 沖頭 |
A round tapered steel pin used to align rivet holes so that the rivet will pass through the holes easily. 用于對齊鉚釘孔的圓形錐形鋼銷，以便鉚釘輕松穿過孔。 |
| DTI | DTI |
Direct tension indicator. A fastener used primarily in the structural steel industry, designed to indicate that a certain minimum amount of tension has been developed in the fastener during assembly. 直接張力指示器。一種主要用于結構鋼行業的緊固件，旨在表明在裝配過程中緊固件中產生了一定的最小張力。 |
| Ductile | 延展性材料 |
(ductile material) Describes a material that can be deformed permanently to large strains without fracture. If a bolt can be stretched well past its yield point before breaking, it is said to be ductile. （延展性材料）描述一種可以永久變形到大應變而不斷裂的材料。如果螺栓在斷裂前可以很好地拉伸超過其屈服點，則稱其具有延展性。 |
| Ductile cast iron | 球墨鑄鐵 |
A cast iron that has been treated while molten with an element such as magnesium or cerium to induce the formation of free graphite as nodules or spherulites, which imparts a measurable degree of ductility to the cast metal. Also known as nodular cast iron, spherulitic graphite cast iron and SG iron. 一種鑄鐵，在熔融時用鎂或鈰等元素進行處理，以誘導游離石墨形成為球粒或球晶，從而賦予鑄造金屬可測量的延展性。又稱球墨鑄鐵、球晶石墨鑄鐵和SG鑄鐵。 |
| Ductile crack propagation | 延性裂紋擴展 |
Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body. 緩慢的裂紋擴展，伴隨著明顯的塑性變形，需要從外部提供能量。 |
| Ductile fracture | 韌性斷裂 |
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy. A fracture of a component or structure which is preceded by extensive ductile deformation so that the broken pieces cannot be re-fitted to regain the original size and shape of the component or structure. 以金屬撕裂為特征的斷裂，伴隨著明顯的總塑性變形和相當大的能量消耗。一種部件或結構的斷裂，在斷裂前會發生大范圍的延性變形，從而使斷裂的碎片無法重新裝配以恢復部件或結構原來的尺寸和形狀。 |
| Ductility | 延展性 |
The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height of cupping in a cupping test, or by the radius or angle of bend in a bend test. 材料在斷裂前發生塑性變形的能力。通過拉伸試驗中的伸長率或面積減少量、杯突試驗中的杯突高度或彎曲試驗中的彎曲半徑或角度來測量。 |
| Durometer hardness | 硬度計硬度 |
Measure of the indentation hardness of plastics. It is the extent to which a spring-loaded steel indenter protrudes beyond the pressure foot into the material. 塑料壓痕硬度的測量。它是彈簧加載的鋼壓頭超出壓力腳伸入材料的程度。 |
| Dynamic compressor | 動態壓縮器 |
A machine, such as a centrifugal or axial compressor, that compresses a gas by rotational rather than reciprocating motion. 一種機器，例如離心式或軸流式壓縮機，通過旋轉而不是往復運動來壓縮氣體。 |
| Dynamic coupling | 動態耦合 |
In vibrations, the existence of inertial terms depending on mass in the governing equations, so that there is only a force if there is a corresponding acceleration. 在振動中，慣性項的存在取決于控制方程中的質量，因此只有當有相應的加速度時才有力。 |
| Dynamic hardness | 動態硬度 |
(rebound hardness) The resistance of a material to local indentation by a rapidly-moving rigid indenter. In most practical methods the indenter is allowed to fall under gravity on to the surface of the material when the rebound height is a measure of the dynamic hardness. （回彈硬度）材料對快速移動的剛性壓頭局部壓痕的阻力。在大多數實際方法中，當回彈高度是動態硬度的測量值時，允許壓頭在重力作用下落在材料表面上。 |
| Dynamic load (Unit N) | 動態負載（單位N） |
1. Loading of a component or structure by a moving object whose point of application changes with time, e.g. the live load of a train passing over a bridge. 2. A load applied to a particular part of a component or structure in a short time interval. 1. 應用點隨時間變化的移動物體對部件或結構的加載，例如通過橋梁的火車的活荷載。2. 在短時間內施加到部件或結構的特定部分的載荷。 |
| Dynamic load rating (Unit N) | 額定動載荷（單位N） |
The allowable load on a component or structure when the loading is not static. 當負載不是靜態時，組件或結構上的允許負載。 |
| Dynamic mechanical measurement | 動態機械測量 |
A technique in which either the modulus and/or damping of a substance under oscillatory load or displacement is measured as a function of temperature, frequency, or time, or a combination thereof. 一種技術，其中在振蕩載荷或位移下測量物質的模量和/或阻尼作為溫度、頻率或時間或其組合的函數。 |
| Dynamic modulus | 動態模量 |
The ratio of stress to strain under cyclic conditions (calculated from data obtained from either free or forced vibration tests, in shear, compression, or tension). 循環條件下的應力與應變之比（根據在剪切、壓縮或拉伸中的自由或強制振動測試中獲得的數據計算得出）。 |
| Dynamic recovery | 動態恢復 |
A process occurring in hot working of metals in which a fine subgrain structure forms within the elongated grains due to annihilation of dislocations due to easy cross slip and climb. It results in a lowering of the flow stress. Dynamic recovery, as opposed to dynamic recrystallization that occurs in hot working, occurs in metals of high stacking fault energy such as aluminum, αiron, and most bcc metals. 金屬熱加工中發生的一種過程，由于易于交叉滑動和攀爬，位錯湮滅，細長晶粒內形成細亞晶粒結構。這導致流動應力降低。與熱加工中發生的動態再結晶相反，動態回復發生在高層錯能金屬中，如鋁、α鐵和大多數bcc金屬。 |
| Dynamic strain aging | 動態應變時效 |
A behavior in metals in which solute atoms are sufficiently mobile to move toward and interact with dislocations. This results in strengthening over a specific range of elevated temperature and strain rate. 金屬的一種特點，其中溶質原子具有足夠的移動能力，能夠向位錯移動并與位錯相互作用，會導致在特定的高溫和應變速率范圍內強化。 |
| Dynamics | 動力學 |
The branch of mechanics that deals with objects in motion. Its two main branches are kinematics, which studies motion without regards to its cause, and kinetics, which also takes into account forces that cause motion. 力學中研究運動物體的分支。它的兩個主要分支是運動學和動力學，前者研究運動而不考慮其原因，后者也考慮引起運動的力。 |