基于伪比能的梁式结构损伤识别

基于结构动应变测试数据,直接在时域内对梁式结构进行损伤识别.相对加速度、位移而言,应变对结构损伤更为敏感,故采用结构动应变测试数据;利用小波包变换,对结构各测点动应变数据进行分析;引入"伪比能"(PSED)概念,提出"平均伪比能"(APSED)和"平均伪比能变化率"(APSEDR)指标,计算后获得结构损伤信息;利用多项式最小二乘法曲线拟合,避免了获取在役结构损伤前信息的困难.数值分析表明:本方法仅凭结构损伤后信息能准确识别结构损伤位置和损伤程度,并具有良好的噪声鲁棒性.

Damage Identification of Beam Structures Based on Pseudo Strain Energy Density

A method based on dynamic strain signals for identifying damage of beam structures in time domain is presented.Dynamic strain signals are adopted since they are more sensitive than acceleration and displacement signals to structure damage. The strain signals are analyzed with wavelet packet transformation firstly.By calculating and analyzing the "average pseudo strain energy density"(APSED) and"average pseudo strain energy density rate"(APSEDR) indices proposed here,the characteristics of structure damages are expressed.Polynomial curve fitting with a least-square calculation is used to avoid difficulties for obtaining the structure information before damaged.Numerical simulation results show that this method possessing satisfactory noise robusticity can also effectively capture the damage location and quantify the damage severity without the structure information before damaged.