基于应变能量分布变化的大跨桥损伤识别

为满足结构在线健康监测大量数据快速计算的要求,以测试的应变信号为基础,探究结构在不同输入下的损伤识别方法.该方法在传统的以曲率模态为基础的能量损伤指标理论上,提出基于应变能量分布变化的损伤指标法(DIM),通过损伤前后结构的响应求出结构各单元的相对应变比能,获得各单元的DIM,进而根据其峰值位置和大小判别结构损伤位置与损伤度.采用该方法对一大跨斜拉桥进行数值分析,结果表明,该方法能够准确地识别出结构的损伤位置,且对结构在损伤前后受不同激励作用的情况均有效,抗噪声污染能力较强.

Damage Detection Strategy for Long-Span Bridge Based on Strain Energy Distribution Change

To meet the needs of rapid calculation of large amounts of data for structure health monitoring,the structure damage identification method is explored based on strain signals under different input.The theory of damage index method(DIM) based on strain energy distribution change is proposed,and it which is different from the early damage index method based on curvature mode.The values of DIM in different elements are calculated through the comparison of strain energy in different elements,when the strain response of structure both in healthy and in damage is abstained.Based on the Matlab and ANSYS numerical simulation,an example of long-span cable stayed bridge is analyzed.The results show that the damage position is accurately located under different incentives and the capacity of anti-noise pollution is improved.