Static And Dynamic Damage Analysis Of Reinforced Concrete Frames

Concrete is a material applied extensively in the civil engineering. The failure mechanism and the failure mode of the concrete are concerned by the experts in the fields of the material science, the mechanics, and the engineering. The failure control is the key problem to the design in engineering. The failure of a structure doesn't happen suddenly, but usually is because of the damage accumulation. The target of the failure control is to prevent the total failure during the service period, namely, to control the extension of the micro-cracks and the micro-cavities within the allowable extent.Fracture mechanics provide the theory for the failure analysis and the control of the RC structure. But, because of the limitation of fracture mechanics, the damage mechanics is proposed. The theory can be used to analyze the total failure process of the structure including the evolution of the micro-cracks, the formation of the macro-cracks and the failure of the members.In this paper, the static, dynamic double-shear damage constitutive theory is modified. By considering the variety of initial elastic modulus under dynamic load, the constitutive equation is improved to be more reasonable. And the increment form of the damage evolution equation is derived in order to be applicable under complicated load.The non-damage constitutive model is well developed and agrees better with the experimental results. In this paper, the total decoupling method is used and the damage analysis of the RC frame under the static, impact and seismic load is accomplished through the combination of FEM software and the program with APDL. The damage field of the RC frame and the evolution of the damage with the change of load and time are obtained. The results can serve as references for the damage assessment and life prediction.