结构裂缝群的小波方法识别和数值模拟

为采用相对简单的方法对桥梁进行损伤识别，从而实现对结构健康状况的监测，基于桥梁裂缝常以裂缝群方式出现这一现象，通过Lipschitz指数与小波消失矩之间的关系．利用小波变换极大值在多尺度上的变化规律来表征信号突变点的性质，从而判定信号有无奇异点并确定其位置．并通过带裂缝简支梁有限元模型的静力模拟，运用前述理论，确定裂缝群的发生及位置．结果表明，较之传统方法，文中方法不仅更为经济方便，而且检测结果更为精确可靠。

Identification of Structural Crack Groups by Means of Wavelet Method and the Numerical Simulation of Crack Groups

The aim of this research is to identify the damages of bridges by using relatively simple methods and to monitor the health situations of the bridge structures. This research is based on the fact that cracks usually exist in the form of crack groups. By analyzing the relationship between the Lipschitz exponent and the wavelet vanishing moment, the characteristics of the signal breaking points are expressed, based on the multi-scale change rules of the maximum value of wavelet transform. Thus, a method is proposed to determine whether there exist singularitiy points in the signal, and where the singularity points are located. By applying the proposed theory to the static force simulation of the finite element model for simple-supported beams with cracks, the occurrence and location of the crack groups are then determined. The results indicate that the proposed method is of greater precision, more facility and lower cost than the conventional method.