【摘要】 针对现有工程基础无损检测中反射波分析的不足,对Morlet和Marr小波及其小波变换进行了深入分析,指出它们在反射波分析上具有优势互补性。结合两个小波的优势,提出了Morlet小波域能量密度谱辨识动力学特征和Marr小波域模谱提取奇异特征的反射波分析方法,并构建了基于小波域香农熵的Morlet最优基小波确定技术。由反射波的动力学特征可以识别损伤模式,由反射波的奇异特征可以实施损伤定位,两者相结合构成了一条有机的基于反射波特征小波分析的工程基础精细无损检测技术路线。模型实验分析中概括归纳了工程基础的基本损伤模式,并验证了技术路线的可行、有效性。更多还原

【Abstract】 Aiming at improving the analysis precision of reflection waves in nondestructive detection for civil engineering foundations,the characters of Morlet and Marr wavelets and the properties of their transforms are thoroughly investigated and the complementary advantages of these two wavelets in reflection wave analysis are discussed in detail. By combining the advantages of these two wavelets,a novel method for reflection wave analysis is proposed,which utilizes power density spectrum of Morlet wavelet to extract the dynamic characteristics of reflection waves and employs modulus spectrum of Marr wavelet to capture the singular features of reflection waves,in addition involves the key technique of using Shannon entropy of wavelet transform to determine the optimal mother wavelet of Morlet wavelet. Damage patterns may be identified in terms of the dynamic characteristics of reflection waves and damage positions may be located in terms of the singular features of reflection waves. Thus a promising technology is constituted for nondestructive detection of civil engineering foundations. The basic damage patterns of civil engineering foundations are demonstrated in the physical model experiment,and the feasibility and effectiveness of the technology are validated by both numerical and physical experiments.更多还原