预应变

But it does not change the variation of coercivity with tension and compression.

但175℃时效并不改变矫顽力随拉伸和压缩的变化，亦即不改变预应变引人的背应力。

Using a model regarding the impeller as homogeneous rotating circular with same thickness and various density,the residual strain field and plastic deformation zone size of certain supercharger impeller were calculated at 30 000 r／min over-speeding preload by means of axial symmetry plane stress elasto-plastic analysis method,and were compared with the result of resistance strain measurement method.

将柴油机涡轮增压器叶轮简化为一个均质、等厚、变密度的旋转圆盘，按轴对称平面应力弹塑性分析方法计算了国产某型增压器叶轮在30 000 r／min超速预加载后的残余应变场和轮内塑性区尺寸；又用电阻应变测量法测得超速叶轮的实际应变。

In this paper,the effect of pre-stress on peen-forming is studied by experiments,the results show that pre-stress can change the relationship between pre-deformation and pre-stress shot peen deformation,and that 0.05%～0.1%pre-strain is comparetively suitable to improve the spanwise rectilinearity of shot peen-forming configuration surface.

文摘：对预应力喷丸成形进行了试验研究，指出预应力可以改变其对应的预变形与预应力喷丸变形之间的大小关系，在以改善喷丸型面纵向直线度为主要目的的预应力喷丸成形中，预应变取值0.5/1000～1/1000较为适宜。

It is found that the effect of SMA on matrix is mainly an edge effect.

如果要对基体的局部进行控制的话，则应将预应变加在SMA相应的局部部位上。

The results show that if the prestrain level exceeds a certain amount, the composite will rupture due to the large recovery stress upon heating.

实验结果表明，当记忆合金丝的预应变较大时，由于较大的回复力而导致复合材料的破坏。

The ductile-brittle transitions due to both temperature and torsional prestrain were discussed by means of the micoscopic parameter ln.

利用扫描电镜测量了BHW60钢、20钢和45钢拉伸试样断口心部的临界空穴扩张比Rc／Ro，并据此分析了由于环境温度和扭转预应变等因素引起的韧脆转变过程及其细观形态。

A model describing the relationship between recovery stress and temperature is developed based on the modified Clausius-Clapeyron equation. A composite model based on the Tanaka model is used to calculate the thermal expansion strain of composite, and the relationship between the martensitic fraction and temperature. Results show that this relationship is nonlinear, affected by prestrain and the heating-cooling history.

利用Tanaka模型以及在Tanaka模型基础上所建立的复合材料的模型，分析了TiNi合金丝/Al基复合材料的热收缩应变，以及复合材料中TiNi合金丝发生逆相变过程中马氏体分数与温度的关系，结果表明马氏体分数与温度之间的关系并非近似线性，而是随着预应变的不同、加热冷却过程的不同而变化的，在具体的使用时应根据不同的情况具体分析。

The mechanical properties of torqued and non-torqued tungsten alloy are also investigated. A constitutive model that describes rate-hardening and strain-hardening effects is also established for these tungsten alloys.

同时对预扭转和未扭转钨合金材料进行了动态力学性能实验研究，建立了考虑应变率硬化、应变硬化效应的动态本构模型。

The applicability of this constitutive model is evaluated with the simulations of material tests conducted by Sasaki et al., includes (1)Uniaxially constant strain amplitude cyclic test,(2)Fast in tension/Slow in compression constant strain amplitude cyclic test,(3)Slow-fast-slow constant strain amplitude cyclic test,(4)Cyclic strain with tensile hold time test. Simulations based on this constitutive model have a good agreement with (1),(2) and (3), proofs that it can describe the cyclic stress-strain behavior of 60Sn/40Pb solder very well.

为验证本模式之能力，本文选择Sasaki等人之实验为对象，分别对60Sn/40Pb焊锡在(1)定应变振幅之循环单轴负荷实验、(2)拉伸快/压缩慢之定应变振幅循环负荷实验、(3)慢-快-慢之定应变振幅循环负荷实验、(4)拉伸应力保持之循环应变实验下的材料行为进行模拟，由(1)、(2)及(3)之结果证明本模式对60Sn/40Pb焊锡循环应力-应变整体行为具有理想的描述能力，并对循环塑性应变范围与应力范围之值有准确的预估。

For the current situation and disadvantages of strain measuring for sheet metal forming,a digital camera based strain measuring system has been set up in this paper.

基于板料应变测量的现状和不足，本文基于数码相机构建了板料应变测量系统，并以图像处理和图像测量的原理为基础，基于C++语言开发了以图像预处理和二值图像的标定和测量为主要模块的板料应变测量软件系统。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。