| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| U-bend | U形管 |
U-bend A 180° bend in a pipe. 180°弯曲的管道。 |
| 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. 两端有螺纹并弯曲成U形的杆。用于夹紧。一种外螺纹紧固件，弯曲成字母U的形状，两端带有螺纹。 |
| 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. 由两个垂直管组成的装置，在顶部或底部通过一段管子连接，形成U形。 |
| Ultimate strength | 极限应力 |
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. 螺栓或材料在断裂前可支撑的最大抗拉强度。总是出现在应力-应变或力-伸长率曲线的塑性区域，因此不是设计强度。也称为抗拉强度和极限抗拉强度。材料在不断裂的情况下能够承受的最大应力（拉伸、压缩或剪切），通过将最大载荷除以试样的原始横截面积来确定。也称为标称强度或最大强度。 |
| Ultrasonic extensometer | 超声波伸长计 |
An electronic instrument which measures the change in length of a fastener ultrasonically as, or before and after, the fastener is tightened. 一种电子仪器，可在紧固件拧紧时或前后通过超声波测量紧固件长度的变化。 |
| Ultrasonic method | 超声波法 |
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. 测量伸长使用在螺栓一端产生的声音脉冲，该脉冲沿螺栓长度传播，从远端反弹，并在测量的时间段内返回到声音发生器。 |
| Uniaxial strain | 单轴应变 |
Increase (or decrease) in length resulting from a stress acting parallel to the longitudinal axis of the specimen. 由平行于试样纵轴的应力引起的长度增加（或减少）。 |
| Uniform elongation | 均匀伸长 |
The elongation at maximum load and immediately preceding the onset of necking in a tension test. 在拉伸试验中，在最大载荷下和颈缩开始之前的伸长率。 |
| Uniform strain | 均匀应变 |
The strain occurring prior to the beginning of localization of strain (necking); the strain to maximum load in the tension test. 在应变局部化（颈缩）开始之前发生的应变；拉伸试验中最大载荷的应变。 |
| Union (union joint) | 活接头 |
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. 一种螺纹管件，允许连接和拆卸两个管道，而无需旋转任何一个管道，且不会损坏管道端部。 |
| Unison ring | 协调环 |
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. 在具有可调导向叶片或定子叶片的涡轮机中，一组叶片连接到的环，当环旋转时，所有叶片角度都可调整。 |
| Unit | 单位 |
A numerical indication of the magnitude of a physical quantity. The basic units of mass, length, time, etc. are relative to agreed standards. 物理量大小的数字指示。质量、长度、时间等基本单位与商定的标准相对应。 |
| Universal joint (Hooke’s joint) | 万向节（胡克接头） |
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. 一种双枢轴连接，允许动力和扭矩以一定角度在两个轴之间传递。对于输入磁轭的恒定驱动角速度，输出磁轭的角速度根据轴的相交角度波动。当插入中间轴时，驱动轴和从动轴的速度可以相同（提供恒定速度接头），中间轴的两端都有万向节。主动轴和从动轴必须与中间轴倾斜相等，中间轴的两个叉必须位于同一平面内。 |