| The stress-strain curves of materials obtained under impact loading generally have significant oscillations. For a long time , it is difficult to judge the authenticity of the oscillations, that is, it is uncertain whether the oscillations are the intrinsic characteristics of 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, and also affects the establishment of the dynamic constitutive relationship of the material and the accuracy of its parameters. This has an impact on the optimal design and safety reliability of major national defense and military and civilian equipment under impact load. In view of oscillation, a common problem that has long plagued scientific researchers and engineering technicians, the research progress about the oscillation phenomenon of the stress-strain curve of materials under impact loading is reviewed. Firstly, the reason for the oscillation in the dynamic test curve is analyzed from the aspects of loading system design, stress wave propagation, and sample deformation distribution; secondly, the methods of suppressing or eliminating the oscillation phenomenon is mainly discussed according to the causes of oscillation; finally, the outstanding problems of the current research are summarized and some suggestions are put forward for the future development direction. |
