The stress and strain concentration in some component has been a significant topic for structural safety assessment. However, the evaluation of the stress and strain concentration based on the widely existing solutions for linear elastic material under static loading would lead to remarkable errors when the material undergoes the dynamic loading, since the coupling effect induced by the nonlinearity of the stress–strain relationship and the strain-rate strengthening could be of significant influence. Here we analyzed the strain-rate dependent concentration of stress and strain for a visco-plastic plate with an elliptic hole subjected to dynamic loading. The three-dimensional stress and strain are calculated by finite element analyses based on a rate-dependent Johnson–Cook model in which the material constants are set according to a typical visco-plastic standard 45 carbon steel. Our results show that both the plastic stress and strain concentration factors significantly depend on not only the strain but also the strain rate. With the increment of the remote strain rate, the stress concentration monotonically increases, while the strain concentration shows decreasing tendency.

中文翻译：

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应变速率对带有椭圆孔的粘塑板中应力和应变集中的影响

某些组件中的应力和应变集中已成为结构安全评估的重要课题。但是，基于线性弹性材料在静态载荷下的广泛存在的解决方案，根据广泛存在的解决方案对应力和应变集中进行评估会导致材料在承受动态载荷时出现显着误差，因为应力-应变关系的非线性会引起耦合效应。应变率的加强可能会产生重大影响。在这里，我们分析了具有椭圆孔的粘塑性板在动态载荷作用下应力与应变的应力集中度。通过基于速率相关的Johnson-Cook模型的有限元分析来计算三维应力和应变，其中材料常数是根据典型的粘塑性标准45碳钢设置的。我们的结果表明，塑性应力和应变集中系数不仅显着取决于应变，而且还取决于应变率。随着远程应变率的增加，应力集中单调增加，而应变集中则呈下降趋势。