弹塑性介质内的波速变化

Wave velocity variation in elastoplastic media

应用一个具体问题展开了波在固体在弹性、弹塑性和应变局部化阶段的传播特性的研究。当经典本构计算到材料出现应变局部化时失效、控制方程出现分叉现象时,非局部效应本构描述得以继续分析,破坏过程变形进一步体现。本构内引入梯度项的贡献,以牺牲了特高频率(>k)特性为代价,增强了控制方程的稳定性。阻尼的影响复杂得多,考虑滞变阻尼、且仅与质量有关时,阻尼对控制方程的稳定性没有贡献。如果阻尼考虑为与质量和刚度联合相关时,阻尼对控制方程稳定性是有一定的贡献。

A specified problem is adopted here to study wave propagation properties in a solid of different states i.e., elastic, elastoplatic and strain localization. When the strain localization occurs, or solution of governing equation is in bifurcation, the classical constitutive model can not be used to analyze further material failure. Gradient dependent constitutive model, contrarily, can improve the capability someway, but characteristic dimension employed in material sacrifices high frequencies. And the capability of viscosity dependent constitutive model relies on what viscosity compose, if density and modulus, it can improve; if density only, it cannot.