一种钢管焊接结构焊接节点损伤识别的新方法

摘要

The damage of welded joints is simulated with a semi-rigid connection model.According to the strain mode theory,a two-step damage detection method is proposed.First,strain modal parame-ters are deduced from displacement modal parameters based on the holistic modal testing and then the improved objective function is used to locate the structural damage correctly by trust region optimiza-tion algorithm.Second,the variation in element-end strain modal index is used to detect the structural damage exactly.The numerical simulation and experimental analysis of engineering examples show that the improved damage detection method is more desirable which provides a new idea for the da-mage detection of welded joints in large welded structures.%采用端部半刚性连接梁单元模型进行模拟焊接节点的损伤，并基于应变模态理论，提出了一种焊接节点损伤识别两步法。第一步，先整体测量结构的位移模态并推导出应变模态，然后采用改进后的目标函数，通过信赖域优化算法对损伤节点位置进行准确判定；第二步，采用提出的杆端应变模态变化比指标，实现焊接节点损伤程度的精确识别。经工程实例的数值仿真及试验分析，验证了该方法的有效性及优越性，为解决这类大型焊接结构焊接节点的损伤识别问题提供了新思路。