摘要
基于模型修正技术的结构损伤识别方法,无需事先知晓结构的损伤位置,比仪器直接探测更具优势。模型修正大多以模态频率和振型为修正目标。然而,结构损伤对系统的模态频率和振型影响较小,采用模态频率和振型为目标的传统修正方法,难以识别出结构的损伤。为此,引入对结构损伤极为灵敏的模态柔度矩阵,研究以模态柔度矩阵为目标函数的损伤识别方法。选取某带孔的矩形长铁片为研究对象,沿其纵向等分为31块,计算模态柔度矩阵关于各等效模量相对量的灵敏度。结合灵敏度矩阵,利用实测和有限元模型间的柔度矩阵残差建立目标函数,并引入正则化方法求解目标函数的超定方程组。经过9次迭代目标函数收敛,损伤识别结果与实际值保持高度一致,从而验证该方法的正确性和实用性。
The damage detection method based on model updating is more convenient and advanced than the traditional instrument detection techniques. In this method, it is not necessary to known the damage locations of structures. The model updating methods are usually based on the targets of mode frequencies and shapes updating. However, the structure damage has little effect on the mode frequencies and shapes. So, the damage can hardly be detected with traditional updating methods which take the mode frequencies and shapes as objectives. In this paper, the mode flexibility matrix, which is very sensitive to the structure damages, was introduced. The structure damage detection method with the flexibility matrix as the objective was studied. A rectangular iron panel with holes was selected as the object of study. It was divided into 31 pieces in longitudinal direction. The mode flexibility matrix sensitivity to each equivalent modulus was calculated. The objective function was established with sensitivity matrix and mode flexibility residual. Then, the ill posed equations of objective functions were solved by regularization method. The objective fimction converged with nine iterations and the result of damage identification was in very good agreement with the real value. It is verified that the method is accurate and practical.
出处
《噪声与振动控制》
CSCD
2015年第4期101-106,共6页
Noise and Vibration Control
关键词
振动与波
结构损伤
模态柔度
模量灵敏度
损伤识别
vibration and wave
structure damage
modal flexibility
modulus sensitivity
damage detection
