混凝土WW三参数率相关动态本构模型

根据一致粘塑性模型理论，结合所做的混凝土单轴动力特性试验，对常用的混凝土本构模型Willam—Warnke三参数模型进行改进，引入应变率的影响，推导了Willam—Warnke材料的动态率相关本构模型；并与试验的应力应变曲线进行比较，结果表明本文模型能够较好地反应混凝土的动力特性；最后，通过对一受冲击荷载的简支梁进行计算，并与线弹性及率无关塑性结果进行比较，结果表明考虑了应变率的影响后梁的动力特性发生了较大的变化。

WW three-parameter rate-dependent dynamic constitutive model

Based on the concept of viscoplastic consistency model, a modified Willam-Warnke three-parameter viscoplastic model with the effect of strain rate on concrete taken into account is developed. The dynamic uniaxial stress-strain response of the experiments carried out by the authors are used as the database to establish the model. Compared this model with experimental results, it shows that the model can well represent uniaxial dynamic tension and compression behavior of concrete. To study the effect of strain rate on dynamic behavior of concrete structures, a simple supported beam subjected to an impact load at the middle of the span is analyzed as an example. Calculated results by employing the present model and those of the linear-elastic model and rate-independent plastic model are compared. It shows that the strain rate dependence of the material not only affects the magnitude of maximum stresses and maximum displacements of the beam, but also affects the stress distribution over the beam.