冲击加载下材料应力应变曲线振荡现象的研究综述

A review on the oscillation phenomenon of stress strain curve of material under impact loading

在冲击加载下获得的材料应力应变曲线往往具有显著的振荡,长期以来由于很难判断振荡的真伪,即不确定振荡是试样材料的本征特性还是纯粹的机械加载等带来的影响,故曲线的振荡往往没有从真实应力应变曲线中直接消除。但这种振荡的存在掩盖了真实的材料响应,导致很难准确确定材料的动态屈服强度,也影响了材料动态本构关系的建立及本构模型参数的准确性,这对重大装备工程在冲击载荷下的优化设计及安全可靠性带来不利影响。针对这个长期困扰科研和工程技术人员的普遍性问题,本文综述了冲击加载下材料应力应变曲线振荡现象的研究进展,首先从加载系统设计、应力波传播、试样变形分布等方面分析了动态测试曲线中出现振荡的原因;其次依据振荡成因重点论述了抑制或消除振荡现象的方法;最后总结了现阶段研究的突出问题,并对未来发展方向提出一些建议。

The stress strain curves of materials obtained under impact loading generally exhibit significant oscillations.For a long time,it has been challenging to determine the authenticity of the oscillations,that is,it is uncertain whether the oscillations are intrinsic characteristics of the sample material or the influence of pure mechanical loading.Therefore,the oscillation of the curve is often not directly eliminated from the true stress strain curve.However,the existence of the oscillation conceals the real material response,making it difficult to accurately determine the dynamic yield strength of the material.It also hampers the establishment of the dynamic constitutive relationship of the material and the accuracy of its parameters.As a result,this has a negative impact on the optimal design and safety reliability of major equipment under impact load.Considering the issue of oscillation,which has long been a problem for scientific researchers and engineering technicians,this paper reviews the progress in the study of the oscillation phenomenon of the stress strain curve of materials under impact loading.Firstly,the reasons for the oscillation in the dynamic test curve are analyzed from the perspectives of loading system design,stress wave propagation,and sample deformation distribution.Secondly,methods of suppressing or eliminating the oscillation phenomenon are discussed primarily based on the causes of oscillation.Lastly,the current research is summarized,highlighting the outstanding issues,and recommendations are provided for future development.