A Study on the Effects of Damage Models and Wavelet Bases for Damage Identification and Calibration in Beams
A Study on the Effects of Damage Models and Wavelet Bases for Damage Identification and Calibration in Beams
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DOI：
10.1111/j.1467-8667.2007.00510.x
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发表时间：
2007-11
期刊：
影响因子：
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通讯作者：
V. Pakrashi;A. O'Connor;B. Basu
中科院分区：
文献类型：
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作者：
V. Pakrashi;A. O'Connor;B. Basu
摘要：利用小波分析进行梁的损伤检测与标定涉及到损伤模型、小波函数的选择、加窗效应以及测量过程中噪声的掩蔽效应等关键因素。本文对含开放裂纹的单跨和多跨梁进行了数值研究。第一自然模态的单跨和多跨梁的开放性裂纹进行了模拟，考虑不同程度的复杂性损伤模型和分析不同的裂纹深度比和裂纹位置。高斯白色噪声已被综合引入到模拟的模式形状和不同的信噪比的影响进行了研究。已经发现基于小波的损伤识别技术是简单、有效的，并且独立于损伤模型和小波基函数，只要满足关于模态和小波基的某些条件。基于小波的损伤校准被发现依赖于许多因素，包括损伤模型和分析中使用的基函数。基于曲率的校准比基于模态形状的校准对损伤程度更敏感。
Abstract: Damage detection and calibration in beams by wavelet analysis involve some key factors such as the damage model, the choice of the wavelet function, the effects of windowing, and the effects of masking due to the presence of noise during measurement. A numerical study has been performed in this article addressing these issues for single and multispan beams with an open crack. The first natural modeshapes of single and multispan beams with an open crack have been simulated considering damage models of different levels of complexity and analyzed for different crack depth ratios and crack positions. Gaussian white noise has been synthetically introduced to the simulated modeshape and the effects of varying signal‐to‐noise ratio have been studied. A wavelet‐based damage identification technique has been found to be simple, efficient, and independent of damage models and wavelet basis functions, once certain conditions regarding the modeshape and the wavelet bases are satisfied. The wavelet‐based damage calibration is found to be dependent on a number of factors including damage models and the basis function used in the analysis. A curvature‐based calibration is more sensitive than a modeshape‐based calibration of the extent of damage.