金属成型,涡轮叶片寿命,金属结构承载能力,装甲侵彻,以及结构金属抗断裂能力等方面的进展,都取决于对金属塑性的深入了解.由于金属塑性响应的内在复杂性,因此要获得这样的了解,就需要持续不断地进行研究工作,并需要在理论、实验和数值方法上有所创新.经典塑性理论虽然在对金属结构受到接近比例载荷的常规应用中具有很大价值,但在涉及象大变形、循环载荷、高温、局部剪切或高应变率的许多重要应用中却不令人满意.必须有一个在物理学基础上发展起来的塑性理论,来解决现代工程技术所面临的种类广泛的问题.发展这种理论,需要有严格的实验,以便揭示微观机理和宏观塑性响应之间的关系,并为确定所提出理论的正确性提供根据.对于发展一个更全面的理论来说,考虑率相关、大变形、非比例载荷、温度敏感性及品界效应等是重要的.计算机的大小和速度的惊人的增长,为利用更符合实际的塑性理论进行计算消除了障碍.放松对计算的约束条件,给与塑性有关的工程技术问题的重大发展提供了一个特殊良机.由于晶粒旋转及空洞扩散之类的效应引起了软化,因此要想适用于涉及这种软化的情况,就需要有精确的有效计算机编码.尤其十分需要预测材料由于形成剪切带和由于空洞并合而引起的破坏的能力.在一般加载历史过程中,必须确定控制损伤 Advances in metal forming, turbine blade life, load carrying capacity of metal structures, armor penetration, and fracture resistance of structural metals all depend on a deep understanding of metal plasticity, due to the inherent complexity of metal plasticity response , There is a need for continuous research and innovation in theory, experimentation and numerical methods.Although classical plasticity theory is of great value in the routine application of metal structures subject to near-proportional loads, Many important applications such as large deformation, cyclic loading, high temperature, local shear or high strain rates are unsatisfactory. There must be a plastic theory developed on the basis of physics to deal with the types of modern engineering technology Wide range of issues.Development of this theory requires rigorous experimentation in order to reveal the relationship between microscopic mechanisms and macroscopic plasticity responses and to provide a basis for determining the correctness of the proposed theory.For the development of a more comprehensive theory, It is important to consider the rate-dependent, large deformation, non-proportional load, temperature sensitivity, and character effects, etc. Large And the alarming increase in velocity have eliminated the barriers to using more plausible plastic theories to relax the relaxation of the computational constraints that give a significant opportunity for major developments in plastic-related engineering problems due to the effects of grain rotation and The effect of cavitations, such as voids, causes softening and, therefore, requires an accurate and valid computer code for applications involving such softening. In particular, it is highly desirable to predict the failure of materials due to the formation of shear bands and consequent voids In the general loading history, we must determine the control damage