【摘要】 提出了一种基于模型修正的钢管焊接结构焊缝损伤识别方法。利用从发射台骨架试验模型获取的模态参数,选择识别结果中精度较好的模态参数作为模型修正的基准参数。提出基于柔度的最小二乘目标函数,极小化结构实测模态柔度与分析模态柔度之间的误差,将损伤识别问题转化为二次优化问题,并采用信赖域方法求解该问题。以有限元模型焊接结点单元组弹性模量的降低模拟焊缝损伤,并假定两种损伤工况,通过对发射台骨架模型的数值仿真及试验研究,表明所提出的损伤识别方法识别效果较为理想,为解决这种复杂焊接结构焊缝损伤识别问题提供了新的思路。更多还原

【Abstract】 A new method for weld seam damage detection on steel tube welded structures based on model updating is proposed.The identified parameters which are more accurate are selected as updating parameters,the Ieast-squares objective function based on flexibility is defined,then the detection problem is transformed into an optimization problem in this method through minimizing the sum of differences between the experimental and analytical modal date,and the trust-region approaching method is then used to solve the minimization problem.Finally,the proposed method is applied for damage detection on the frame of a launch platform.The elastic modulus reduction of jointing crunodes elements group is taken to simulate the weld seam damage state and two cases are investigated.The simulation and experimentation results show that the proposed method is well suitable for weld seam damage detection on such complex steel tube welded structures.更多还原