基于应变模态的钢结构构件焊缝损伤定位方法的研究

The methods of identifying damage location for weld in members of steel structure based on strain mode

本文探讨了用应变模态对钢结构焊缝损伤进行识别与定位的方法。应变模态对结构局部损伤的反应敏感,是对结构进行微小损伤诊断的较理想的损伤识别指标。文中以一简支工字型梁为研究对象,分别采用基于应变模态差的三种定位准则和神经网络方法,对其进行了单处和两处焊缝损伤定位的研究。结果表明,基于应变模态差的定位准则对于这两种情况的损伤都具有较高的定位识别率,但不能区别出单处和两处损伤;而采用神经网络方法不仅可以区别出单处和两处损伤,而且训练好的网络对受噪声污染的测试样本也具有较好的识别效果。

The approaches to identify and locate weld damage in members of steel structure are discussed by using strain mode in this paper. Because strain mode is very sensitive to local damage in the structure, it is an ideal damage identification signature to diagnose minute damage. In the paper, by using three damage location principle based on strain mode and neural network methods, the approach to locate single and double weld damage in a simply support steel beam with open I-formed is investigated respectively. It is show that the damage location principle based on the difference of strain mode has the more accurate identification ratio to damage, while the neural network method can not only distinguish single or double damage, but the trained-over neural net has the quite good identification effect to the test sample contaminated by noise.