冲击加载下样品软回收过程中的侧向稀疏效应

发布时间：2018-06-27 03:29

本文选题：固体力学 + 侧向稀疏　；参考：《爆炸与冲击》2016年04期

【摘要】：通过数值模拟,计算冲击加载下样品经历一维应变加载过程和侧向稀疏过程产生的塑性功,给出试样内部从冲击加载开始到进入回收桶前全过程的应力随时间变化的历程。结果表明:侧向稀疏过程开始后,样品在径向汇聚波的作用下受循环拉、压载荷作用,拉压循环的振幅在中等冲击压力下达到最大。如果振幅超过了材料的层裂强度,样品中心将发生拉伸破坏不能完整回收。侧向稀疏与一维应变加载产生的塑性功之比随冲击速度的增加而减小。在冲击速度为某临界值时,侧向稀疏产生的塑性功与一维应变加载产生的塑性功相等。在一定的冲击速度下,采用低初始屈服应力的材料可减轻侧向稀疏效应。对理想塑性材料的理论分析表明,侧向稀疏与一维应变加载产生的塑性功之比随冲击速度与屈服强度比值的增大而减小,与数值模拟结果一致。
[Abstract]:By means of numerical simulation, the plastic work of samples subjected to one-dimensional strain loading and lateral sparseness under impact loading is calculated, and the time varying history of the stress in the whole process from the impact loading to the recovery barrel is given. The results show that after the lateral sparseness process begins, the sample is subjected to cyclic pull and compression load under the action of radial convergent wave, and the amplitude of the pull-compression cycle reaches its maximum at medium impact pressure. If the amplitude exceeds the spallation strength of the material, tensile failure will occur in the center of the sample and can not be recovered completely. The ratio of plastic work produced by lateral sparsity to one-dimensional strain loading decreases with the increase of impact velocity. When the impact velocity is a critical value, the plastic work generated by lateral sparsity is equal to that produced by one-dimensional strain loading. At a certain impact velocity, the lateral sparsity effect can be reduced by using the material with low initial yield stress. Theoretical analysis of ideal plastic materials shows that the ratio of plastic work produced by lateral sparseness to one-dimensional strain loading decreases with the increase of the ratio of impact velocity to yield strength, which is in agreement with the numerical simulation results.
【作者单位】：中国工程物理研究院流体物理研究所冲击波物理与爆轰物理重点实验室;
【基金】：国家自然科学基金项目(11272296) 中国工程物理研究院面上基金项目(2012B0201017) 冲击波物理与爆轰物理重点实验室基金项目(2012-专-06)
【分类号】：O347.3

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