底支承对小口径反射镜镜面变形的影响

论述了运用有限元技术研究镜面变形的方法及分析底支承在不同口径，焦比、厚径比和相对支承半径时镜面变形的技术；在取得的相互关联的最大镜面变形数据基础上，研究了影响小口径反射镜底支承镜面变形的因素。     

Q195冷轧板材轧制困难原因分析

针对部分Q195冷轧板材存在轧制困难的现象，进行了现场检验与分析。带状组织、混晶现象严重导致变形强化系数偏高是造成轧制困难的主要原因。     

橡胶Mooney—Rivlin模型材料系数对轴向刚度影响分析

在橡胶小变形范围内，采用理论推断的方法，得到在相同硬度下橡胶Mooney—Rivlin模型材料系数由C2／C1决定的关系式。并采用ABAQUS有限元软件分析的方法，结合橡胶轴向刚度常规解，分析了C2／C1不同值对橡胶轴向刚度的影响进行，结果显示其影响呈现一定规律性。     

Modelling of Al2O3 Powder Compaction with Hot Pressing in a Rigid Die

Computer modelling of hot pressing is provided. Kinetics are described for compaction during hot pressing in a rigid die, and the change in density distribution, irreversible solid phase strain accumulation, and equivalent stresses are studied by means of the finite element method. Shrinkage during the preparation of complex-shaped articles by hot pressing pure Al₂O₃ powder in a graphite die without a protective atmosphere and the physicomechanical properties of the finished article are studied. Calculated and experimental results agree satisfactorily.     

垂直定向液晶光阀及光电特性的研究

系统地讨论了排列相畸变模式液晶光阀结构，原理和制作，结合实际测试对其等效电路和电学匹配进行了分析，详细讨论了它的光电特性及相互关系，实测的液晶垂直排列方式工作的液晶光阀性能指标为，分辨率大于５０ｌｐ／ｍｍ，白光输入灵敏度为６．７７μＷ／ｃｍ＾２，响应时间为２００ｍｓ／３００ｍｓ，白光输出对比度为２００：１。     

冷弯型钢纵向变形的理论分析及计算

对冷弯型钢的纵向变形过程进行了力学分析，得到了变形微分方程，求得了转动角的理论公式，并对其变形形状进行了分析计算。     

34CrMoV结构钢动态再结晶行为研究

应用Gleeble-1500热模拟实验机进行等温压缩试验,研究了变形工艺参数对34CrMoV结构钢动态再结晶行为的影响.结果表明,其流变应力随变形温度升高而降低,随应变速率提高而增大;随着应变速率的降低,应变量的增加和变形温度的升高,动态再结晶速度加快且奥氏体晶粒得到细化.     

A Study of Surface Deformation during Wire‐Rod Rolling of High Speed Steels using Experimental and Computational Techniques

The evolution of surface defects during shape rolling of high‐speed steel billets is studied using longitudinal surface defects prepared by machining and welding. The reduction of the defects during rolling in a production mill is compared to the total area reduction of the billets. Samples are collected after pass 4, 6, 8, 14, 19 and the final pass, 28, representing the finished 5.5mm wire. By inspecting the cross sections, the rotation of the billets from pass to pass is evaluated. Results from FE simulations on solid billets are compared to the experimental results. Generally, simulations predict less reduction than observed experimentally. In most cases cracks reduce most effectively followed by carbon steel welds and stainless steel welds.     

碳钢高温变形后的静态软化行为

在形变温度为1133K、形变速率为2×10~(-3)s~(-1)的试验条件下,采用两段加载拉伸试验方法研究了0.4%C-1.5%Mn钢高温变形后的静态软化行为.调查了由两次加载拉伸变形时的屈服应力求得的静态软化率以及相对峰值应力比和峰值应变比随等温保持时间的变化.详细讨论了动态回复组织和动态再结晶组织对高温变形后的静态软化过程的影响.     

Cyclic X-Y mechanical tests: A new method to perform in situ reversed-deformation experiments in the high-voltage electron microscope

There has been, in the past, only limited success with in situ cyclic or reversed plastic deformation tests in the transmission electron microscope (TEM). This is probably partly due to problems associated with buckling of the foil when an applied tensile or shear stress is reversed. Mechanical analysis shows that dislocation movement can be reversed by tensile stressing in alternating perpendicular directions (i.e., 90° rotations of a tensile stress); thus buckling of the foil can be avoided. A design for performing such X-Y in situ TEM tests is presented, with observations that demonstrate its feasibility.