Static & Dynamic Elastoplastic Damage Model For Concrete And Its Application To The Analysis Of Concrete Dams

Anisotropic elastoplastic damage model with multiple damage failure criteria (MDFC) and rate-dependent damage model for concrete correlating with damage sensitive and rate-dependent of concrete are constructed. The models are used to analyze damage response for 200m grade concrete gravity dams and 300m grade arch dams under static overflow, earthquake and dam safety assessment resisting earthquake. Damage variable is split into tensile and compressive components to depict concrete failure due to tension or compression and to be used to analyze unilaterial effect under cyclic loading in concrete damage theory. With the splitting, different failure mechanism from tension or compression can be found in the process of concrete failure. The MDFC with three different damage failure functions expressed by effective stresses is improved from multiple plastic failure criteria. Rate-dependent damage evolution equation (RDEE) is educed with the principle of energy equivalent in damage mechanics theory and references of concrete dynamic experiments. The potential failure or progressive failure patterns of the dams under overflow loads or earthquake can be simulated numerically with the models through damage responses. Responses of the dams with the suggested model show the model and damage mechanics method are effective tools to numerical analysis and damage safety assessment for dams under earthquake.On the one hand, the MDFC with three different damage-plastic failure functions is suggested, which can not only deal with failure from compressive damage, tensile damage degradation under related axes but also consider anisotropic characteristic for damage. Furthermore, anisotropic damage failure criteria is proposed. Tensile and compressive damage variables together with elastoplastic damage under tension and compression are considered. And the latter is paid more attention to because it is more disadvantageous to the safety of dams.The damage variables used in the criteria are achieved from damage evolution equation considering multiple failure condition. Most concrete structures work under biaxial or triaxial stress state, which have different stress-strain relationships from the uniaxial one, especially at the stage of strain softening. The damage evolution equation accompanying with the constitutive relationship of multiaxial stresses (multiple damage evolution equation, shorting for MDEE) is improved from that of uniaxial stress state (UDEE). A multiaxial effective...