基于模态曲率理论的轨底隐蔽性伤损识别装置及方法研究  

Research on the Identification Device and Method of Concealed Damage of Rail Base Based on Modal Curvature Theory

作　　者：刘艳 李义新 袁贤浦 李秋彤 LIU Yan;LI Yixin;YUAN Xianpu;LI Qiutong(Shanghai Research Institute of Materials,Shanghai 200437,China;Shanghai Engineering Research Center of Earthquake Energy Dissipation,Shanghai 200437,China;School of Resources and Environmental Engineering,Shanghai Polytechnic University,Shanghai 201209,China)

机构地区：[1]上海材料研究所,上海200437 [2]上海消能减震工程技术研究中心,上海200437 [3]上海第二工业大学资源与环境工程学院,上海201209

出　　处：《铁道标准设计》2023年第11期61-67,75,共8页Railway Standard Design

基　　金：上海市青年科技启明星基金项目(19QB1401100)。

摘　　要：针对钢轨轨底隐蔽性伤损(发展初期难以检出)威胁行车安全的问题,基于模态曲率理论提出了轨底隐蔽性伤损识别方法。基于此方法设计出一种轨底隐蔽性伤损识别装置,解决了传统模态测试方法的锤击精度和锤击点密度无法满足伤损识别要求的问题,经对比试验分析:该装置将识别误差降低了2个数量级;采用该装置对预制10 mm轨底裂纹的钢轨进行伤损识别试验,获取模态曲率参数,实现隐蔽性伤损的有效识别;探究多种基于模态曲率理论的伤损识别方法对轨底隐蔽性伤损的识别效果,以振型曲线的峰值与本底噪声绝对值的最大值的比定义“信噪比”。结果表明:模态曲率差法“信噪比”最高,为14.32 dB,且通过振型曲线能够明确判定出伤损位置,相较于其他方法,模态曲率差法具有更适合表征钢轨轨底隐蔽性伤损的特性。Aiming at the problem that the hidden damage of the rail base is difficult to detect in the early stage of development,which threatens the train safety.A method for identifying the concealed damage of the rail base was proposed based on the modal curvature theory.Based on this method,a hidden damage identification device for the rail base was designed,which solved the problem that the hammering accuracy and hammering point density of the traditional modal test method cannot meet the requirements of damage identification.After comparative test analysis:the device reduced identification errors by two orders of magnitude.The device was used to perform damage identification test on prefabricated 10mm rail base cracked rails,obtained modal curvature parameters,and realized the effective identification of concealed damage.The effect of various damage identification methods based on modal curvature theory on the identification of hidden damages at the rail base was explored.And the signal-to-noise ratio(SNR) was defined by the ratio of the peak value of the mode curve to the maximum value of the absolute value of the background noise.The results showed that the SNR of the modal curvature difference method was the highest,which is 14.3 dB;and the damage location could be clearly determined by the mode shape curve.And compared with other methods,the modal curvature difference method is more suitable for characterizing the hidden damage in the rail base.

关 键 词：钢轨 轨底隐蔽性伤损 伤损识别装置 模态曲率理论 模态曲率差 信噪比 

分 类 号：U213.4[交通运输工程—道路与铁道工程] TU311[建筑科学—结构工程]