单轴循环压缩载荷下混凝土实时损伤演化规律

Real-time damage evolution of concrete under axial cyclic compression load

通过循环压缩加载实验并同时运用超声波探测仪实时测试混凝土试样超声波波速变化,得到了不同应变率条件下循环压缩应力应变曲线及超声波波速实时演化结果。结合超声波波速实时测试结果,将加载过程中材料动弹性模量的衰减与材料初始弹性模型比值的变化表征为材料损伤变量,得到了实时损伤演化实验量化结果,并提出了率相关的损伤演化模型。结果表明提出的损伤演化模型可真实地表征混凝土破坏全过程材料实时损伤演化情况,且对研究混凝土材料失效具有重要的理论意义。

Uniaxial cyclic loading tests and ultrasonic real-time test experiment are carried out to obtain ultrasonic velocity evolution of concrete under three different strain ratios. Combining the real-time test result of ultrasonic wave velocity,the evolution of the ratio between degradation of dynamic modulus and the initial modulus of concrete during the loading process was represented as material damage variable,and a damage model was proposed with the real-time damage experiment data based on the result of ultrasonic velocity. The result indicates that the proposed damage model could well represent the whole process of damage fracture of concrete,and the proposed damage model is of great significance in studying the fracture of concrete.