基于混凝土损伤塑性模型的弯曲损伤RC/PC桥梁动力学特性研究OA北大核心CSTPCD

Based on the concrete damage plasticity model,the dynamic characteristics of bending damaged RC/PC bridges are investigated through numerical simulations in this paper.Firstly,a FE model generation framework was proposed to conduct the nonlinear vibration analysis of RC/PC bridges.Then,the constructed FE model was validated by comparison with experimental results from bending failure tests on simply supported RC beams.Finally,a 3D FE model of a 3-span PC continuous girder bridge from the Xiamen Bus Rapid Transit was established to study the changes in frequencies and mode shapes under different bending damage levels.It can be observed from the results that the dynamic characteristics of RC/PC bridges with bending damage change to varying degrees as the damage increases.The small vibration of the damaged bridge with concrete cracks is still linear,but the frequency decreases with the increasing vibration amplitude,indicating the nonlinear vibration.When cracks are closed,the changes in the first three frequencies and mode shapes are not significant,making it hard to identify bending damage in practice.However,when cracks are open,noticeable changes occur in the first three frequencies and mode shapes,which can serve as damage detection indicators for identification purposes.