移动载荷作用下简支梁的动态响应及裂纹损伤识别研究

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振动与冲击 ›› 2011, Vol. 30 ›› Issue (6) : 97-103.

论文

移动载荷作用下简支梁的动态响应及裂纹损伤识别研究

赵俊1,2; 张伟伟3; 马宏伟1

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Dynamic Response and Crack detection of Simply Supported beam under moving loads

ZHAO Jun1,2 ;ZHANG WEI-wei3; MA Hong-wei2

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摘要

基于小波多分辨率分析的方法，根据移动载荷作用下简支梁动态响应特性，利用梁上一点振动信号对裂纹梁进行损伤识别。移动载荷经过梁上裂纹处时，必然导致梁响应时间历程曲线的奇异性，这种奇异性不能直接被观察到，但是可以通过小波多分辨率分析进行识别。利用有限元Ansys软件的瞬态分析方法进行裂纹梁移动载荷作用下的损伤识别数值模拟，通过梁上某一点挠度、速度和加速度的振动信号，利用小波多分辨率分析有效地识别出单个及多个裂纹，同时扩展到多个同向和相向移动载荷作用下裂纹梁的损伤识别。最后，通过不同小波函数的分析结果比较，寻找更加有效的小波函数。以上的损伤识别方法均在较低的移动载荷速度作用下有效，随着速度的增加，裂纹梁损伤识别的有效性越差

Abstract

The objective is to show the potential of the crack detection method based on Multi-resolution Analysis of Wavelet, which is depending on the response at a single point on a beam-like structure subject to concentrated moving loads. When moving along the structure ,the moving loads cause small distortions in the dynamic response of the beam-like structure at the crack locations .In general, these small distortions are difficult to detect visually. An ANSYS model of a cracked beam is established. The moving load is transient analyzed by shifting the point of the concentrated force. The response at mid-span of the beam-like structure is calculated and Wavelet Multi-resolution transformed. The crack on the beam-like structure can be found by position of peak of Wavelet Multi-Resolution Analysis, also the velocity and acceleration of the moving load. Furthermore, By the Principle of superposition, the solution obtained for a single moving load will be expanded to deal with a series of identical , equi-distant moving loads and opposite direction moving loads, by which the key parameter dominating the dynamic response of the beam-like structure can be identified. Finally, The effects of several cracks location and the best wavelet selection are discussed in detail. The proposed method is applicable for low velocity-movements while high velocity-movements are not recommended

导出引用

赵俊;张伟伟;马宏伟. 移动载荷作用下简支梁的动态响应及裂纹损伤识别研究[J]. 振动与冲击, 2011, 30(6): 97-103

ZHAO Jun;;ZHANG WEI-wei;MA Hong-wei. Dynamic Response and Crack detection of Simply Supported beam under moving loads[J]. Journal of Vibration and Shock, 2011, 30(6): 97-103