基于分形理论的高强混凝土动态损伤本构关系

Dynamic damage constitutive relationship of high strength concrete based on fractal theory

基于高强混凝土(HSC)试块在SHPB冲击实验中的分形损伤演化规律,推导了HSC的分形损伤变量表达式,标定了HSC裂纹的分形维数范围。然后参考ZWT模型,并结合HSC实验过程中的应变率相关性、动态损伤特性及近似恒应变率,推导了分形损伤演化的HSC动态损伤本构方程。采用4组应变率工况下的C60、C80混凝土应力-应变曲线对本构方程进行验证,理论曲线和实验曲线吻合较好。

Based on the fractal damage evolution law of high strength concrete（HSC）specimen by the SHPB impact test,we deduced the patterns of the fractal damage variables of HSC,and calibrated the fractal dimension range of the HSC cracks.Then following the ZWT model,and in combination with the strain rate dependence,dynamic damage characteristic and quasi-constant strain rate,we obtained the HSC dynamic damage constitutive equation with the fractal damage evolution taken into account Finall.Our study verified the effectiveness of the constitutive equation by C60 and C80 stress-strain curves at four different strain ratios,and the theoretical curves matched well with the experimental ones.