【摘要】 将小波的强局部分析能力和分形的强非线性处理能力进行优势联合,采用平移不变小波变换(UDWT)记录波形分频,提取深层有效缺陷信息;对缺陷频段实施分形分析,在敏感尺度段内设立关联维阀值判据,实现缺陷和故障的参数化振动诊断。模型实验证明该技术对无损检测领域弱故障信息的提取和大规模地下土木结构的缺陷普查有着较大的应用潜力。文中还讨论了关联维的影响因素,对UDWT和改进关联维方法编制了相应计算程序。更多还原

【Abstract】 A novel method of nondestructive testing is proposed which combines the advantage of wavelet in signal local analysis with that of fractal in nonlinear handling.Firstly,UDWT is used to divide the raw wave into different channels in frequency field to extract the deep information including fault;secondly, based on fractal analysis, the correlation dimension criterion is set up in the sensitive scales interval to realize parameterized detection of weak fault. Model experiments prove that the proposed technology is effective in nondestructive field such as weak fault characteristics deriving from machine vibration and general investigation of fault in underground civil engineering.In addition,the influence factors to correlation dimension are discussed and the computing procedures of UDWT and progressive correlation dimension method are developed.更多还原