脆性材料水泥砂浆多轴应力下的动态响应分析

Dynamic response of brittle material cement mortar under multi-axial stress

在实际的结构应用中,混凝土类材料一般处于复杂工作应力状态,且可能承受动态荷载的作用。据此,本文采用Instron3421液压伺服试验机和具有主动围压加压装置的SHPB研究了混凝土材料-砂浆宽应变率范围多轴应力下的动态力学行为;基于Johnson-Cook强度模型框架,确定了等效强度模型的率相关参数及其他材料常数;提出了适用于描述主动围压下砂浆受冲击荷载的损伤演化规律,并确定了损伤演化常数,实验数据与理论值吻合较好。

Concrete materials used in structures generally work in state of complex stress and may bear dynamic loads.So,an instron servo-hydraulic testing system and a SHPB with a confining pressure device were used here to investigate the dynamic behavior of a concrete material-mortar under multi-axial stress in a wider range of strain rate.According to Johnson-Cook equivalent strength model,the strain rate coefficient and the related material constants of the mortar were determined experimentally.The damage evolution law of the mortar under SHPB impact with a confining pressure was presented and the damage evolution parameters were determined by experiments.The experimental data agreed well with the theoretical values.