【摘要】 以梁板桥为研究对象,分别建立完好和带裂缝板的有限元模型,计算出随机行车激励的多种移动载荷工况下控制点的加速度时程响应。对加速度时程进行时域内微元分段,开展频谱分析得到频谱图,形成以概率统计算法处理具有不确定性的损伤识别问题的方法。基于板损伤后固有频率降低的概率意义和各个工况下指征频率的统计特征,构建板损伤识别的性能函数。用损伤性能函数表达结构损伤状态,计算不同结构损伤状态的概率。计算结果与结构开裂及裂纹延伸发展趋势一致。更多还原

【Abstract】 Taking slab bridge as the research object,the finite element models of intact and cracked slabs were established respectively. With various live loads of random running vehicle excitations,the acceleration time-history responses at the measuring points were calculated,and the acceleration time-history was piecewise in the time domain,and spectrum analysis was carried out to get the spectrum. A probabilistic statistical algorithm was developed to deal with the problem of uncertain damage identification. Based on the probabilistic significance of the reduction of the natural frequency after plate damage and the statistical characteristics of the indication frequency under various working conditions,the performance function of plate damage identification was established. The structural damage state was expressed by the damage performance function,and the probability of different structural damage states was calculated. The calculated results agree well with the development trend of structural cracking and crack extension.更多还原