基于振动响应统计特征的简支梁桥损伤检测
Damage detection of simply-supported beam bridge based on statistics characteristic of vibration responses

为摆脱简支梁桥结构损伤检测时对其完好状态下响应信息的依赖，基于结构振动响应统计特征和提升小波变换，提出一种不需要简支梁桥结构完好状态下的响应信息即可实现损伤检测的新方法。利用提升小波变换分别对简支梁桥的位移响应和曲率响应进行分解，分别提取2种响应分解后重构得到的低频响应，计算出相应的标准差曲率，从而构建2种损伤检测指标。通过有限元数值仿真，分别考察这2种指标对测量噪声和测点稀疏的敏感性，发现2种指标具有可行性；通过简支梁桥模型实验，证实了基于曲率响应的损伤检测指标的有效性。
In order to get rid of the dependency of response information of intact structure, a novel structural damage detection method is proposed. This method, which is free from the response information of intact structure, is based on statistics characteristic of vibration response and lifting wavelet transform. The lifting wavelet is conducted to decompose the displacement responses and curvature responses of simply–supported beam bridge to gain the corresponding standard deviation curvature of the reconstructed response signal of the final level，and then，the corresponding damage detection indexes are constructed. The sensitivity of the two damage indexes to the noise and density of measurement points are investigated by finite element numerical simulation. It is found that the two damage indexes are feasible. Finally, the validity of the damage detection index based on curvature responses is verified through experiments of the simply supported beam bridge model