| 詞或詞組 | 中文 | 英文解釋中文解釋 |
|---|---|---|
| U-bend | U形管 |
U-bend A 180° bend in a pipe. 180°彎曲的管道。 |
| U-bolt | U型螺栓 |
A rod threaded at both ends and bent into a U-shape. It is used for clamping. An externally threaded fastener bent in the shape of the letter U and with both ends threaded. 兩端有螺紋并彎曲成U形的桿。用于夾緊。一種外螺紋緊固件，彎曲成字母U的形狀，兩端帶有螺紋。 |
| U-tube | U型管 |
A device consisting of two vertical tubes connected at either the top or bottom by a length of tubing such that a U-shape is formed. 由兩個垂直管組成的裝置，在頂部或底部通過一段管子連接，形成U形。 |
| Ultimate strength | 極限應力 |
The maximum tensile strength a bolt or material can support prior to rupture. Always found in the plastic region of the stress–strain or force–elongation curve, and so is not a design strength. Also called Tensile strength and ultimate tensile strength. The maximum stress (tensile, compressive, or shear) a material can sustain without fracture, determined by dividing maximum load by the original cross-sectional area of the specimen. Also known as nominal strength or maximum strength. 螺栓或材料在斷裂前可支撐的最大抗拉強度。總是出現在應力-應變或力-伸長率曲線的塑性區域，因此不是設計強度。也稱為抗拉強度和極限抗拉強度。材料在不斷裂的情況下能夠承受的最大應力（拉伸、壓縮或剪切），通過將最大載荷除以試樣的原始橫截面積來確定。也稱為標稱強度或最大強度。 |
| Ultrasonic extensometer | 超聲波伸長計 |
An electronic instrument which measures the change in length of a fastener ultrasonically as, or before and after, the fastener is tightened. 一種電子儀器，可在緊固件擰緊時或前后通過超聲波測量緊固件長度的變化。 |
| Ultrasonic method | 超聲波法 |
Measuring elongation uses a sound pulse, generated at one end of a bolt, that travels the length of a bolt, bounces off the far end, and returns to the sound generator in a measured period of time. 測量伸長使用在螺栓一端產生的聲音脈沖，該脈沖沿螺栓長度傳播，從遠端反彈，并在測量的時間段內返回到聲音發生器。 |
| Uniaxial strain | 單軸應變 |
Increase (or decrease) in length resulting from a stress acting parallel to the longitudinal axis of the specimen. 由平行于試樣縱軸的應力引起的長度增加（或減少）。 |
| Uniform elongation | 均勻伸長 |
The elongation at maximum load and immediately preceding the onset of necking in a tension test. 在拉伸試驗中，在最大載荷下和頸縮開始之前的伸長率。 |
| Uniform strain | 均勻應變 |
The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test. 在應變局部化（頸縮）開始之前發生的應變；拉伸試驗中最大載荷的應變。 |
| Union (union joint) | 活接頭 |
A threaded pipe fitting that allows two pipes to be connected anddetached without the need for either to be rotated, and without damaging the pipe ends. 一種螺紋管件，允許連接和拆卸兩個管道，而無需旋轉任何一個管道，且不會損壞管道端部。 |
| Unison ring | 協調環 |
In a turbomachine with adjustable guide or stator vanes, the ring to which a set of vanes is linked such that when the ring is rotated, all vane angles are adjusted. 在具有可調導向葉片或定子葉片的渦輪機中，一組葉片連接到的環，當環旋轉時，所有葉片角度都可調整。 |
| Unit | 單位 |
A numerical indication of the magnitude of a physical quantity. The basic units of mass, length, time, etc. are relative to agreed standards. 物理量大小的數字指示。質量、長度、時間等基本單位與商定的標準相對應。 |
| Universal joint (Hooke’s joint) | 萬向節（胡克接頭） |
A double-pivoted connection that allows power and torque to be transmitted between two shafts at an angle to each other. For constant driving angular velocity of the input yoke, the angular velocity of the output yoke fluctuates by amounts depending on the angle of intersection of the shafts. Speeds of the driving and driven shafts may be made identical (giving a constant-velocity joint) when an intermediate shaft, at each end of which there is a universal joint, is interposed. The driving and driven shafts must be equally inclined to the intermediate shaft, the two forks of which must lie in the same plane. 一種雙樞軸連接，允許動力和扭矩以一定角度在兩個軸之間傳遞。對于輸入磁軛的恒定驅動角速度，輸出磁軛的角速度根據軸的相交角度波動。當插入中間軸時，驅動軸和從動軸的速度可以相同（提供恒定速度接頭），中間軸的兩端都有萬向節。主動軸和從動軸必須與中間軸傾斜相等，中間軸的兩個叉必須位于同一平面內。 |