Cosserat连续体模型中本构参数对应变局部化模拟结果影响的数值分析

基于所发展的压力相关弹塑性Cosserat连续体模型及相应的数值方法,以一维剪切层及二维平板压缩问题为例,数值分析了Cosserat连续体模型中的本构参数Cosserat剪模、软化模量及内部长度参数对应变局部化数值模拟结果的影响.结果表明在一定取值范围内,Cosserat剪模对数值模拟结果几乎没有影响,并给出了具体数值计算时的取值范围;软化模量绝对值越大,后破坏段的荷载-位移曲线越陡,计算得到的剪切带宽度越窄;内部长度参数越大,后破坏段的荷载-位移曲线越平缓,计算得到的剪切带越宽.

Numerical analysis for the effects of constitutive parameters in Cosserat continuum model on the simulation results of the strain localization

With the examples of a shear layer subjected to a prescribed transverse shear and a square panel subjected to a prescribed vertical displacement,the effects of constitutive parameters,such as Cosserat shear module,the softening module and the internal length scale for modelling the softening behaviour and adhering to the Cosserat continuum,on the simulation results of the strain localization,are numerically studied based on the finite element(FE) procedure developed for pressure-dependent elasto-plastic Cosserat continuum model. It is pointed out that the value of Cosserat shear module chosen within certain range has no effect on the results;the greater the absolute value of the soften modules is,the steeper the post-failure curve of load-displacement is and the narrower the width of shear band is;the greater the value of the internal scale is,the flatter the post-failure curve of load-displacement is and the wider the width of shear band is.