基于移动荷载作用下的结构响应及小波分析的桥梁损伤诊断

Bridge damage detection based on moving load induced structural response and wavelet analysis

用扭转弹簧模拟裂缝损伤,推导了移动荷载作用下裂缝损伤梁的动力响应.通过对损伤梁在移动荷载作用下的位移响应参数进行小波变换,用小波系数灰度图和小波系数模极大值轨迹图识别损伤位置,用可以评价信号奇异性特征的Lipschitz指数评价损伤程度,考察了不同损伤程度、多损伤位置和测点位置,荷载速度和荷载大小及噪声等因素的影响.数值计算表明该方法具有很好的识别效果.

With the crack modeled rotational spring,the responses of damaged bridge subjected to moving load are derived.By applying the wavelet transform to the responses,the damage can be located by the contour plot of wavelet coefficients and the locus of wavelet coefficients modulus maximum.Meanwhile,the damage degrees can be evaluated by Lipschitz exponent which can estimate the signal singularity.The influences of different damage degrees,multiple damage,different sensor locations,load velocity,load magnitude and noise are studied.The numerical examples show that this method is effective and applicable.