基于传递率函数的预制混凝土夹心保温墙板连接件损伤识别

Damage identification of shear connectors in precast concrete sandwich panels based on the transmissibility function

为解决预制混凝土夹心保温墙板中连接件检测困难问题,提出了基于传递率函数的连接件损伤识别方法。首先介绍了传递率函数原理,建立了用于检测预制混凝土夹心保温墙板中损伤连接件的传递率函数理论模型,得出可用预制混凝土夹心保温墙板物理参数表示的传递率损伤指标(transmissibility damage indicator,TDI)。分析理论模型的检测机理表明,该方法不仅可以判断连接件损伤程度而且检测结果不受未被检测损伤连接件干扰。分别设置单损伤和多损伤工况,通过缩尺模型试验,验证了所提出检测方法的可行性,试验结果表明,损伤连接件和无损连接件的TDI指标之间存在着明显的不同,差异达到39.2%,所提出方法可以有效确定连接件的损伤状态与程度,且多损伤工况下其他未被检测的损伤连接件对检测结果无影响。进一步通过数值模拟结果测试所提出方法的抗噪性,建议使用该方法时,保证信噪比在40 dB以上,从而保障方法的鲁棒性。

To solve the difficulty in the damage detection of shear connectors in precast concrete sandwich panels,a damage identification method based on the transmissibility function was proposed.The basic knowledge about transmissibility function was described,and then a theoretical model based on the transmissibility function to detect damaged shear connectors was established.A transmissibility damage indicator(TDI)represented by the physical parameters of the precast concrete sandwich panel was introduced.The theoretical analysis on the indicator mechanism reveals that the proposed method can not only reflect the damage degree of the shear connector but also retain undisturbed by other adjacent shear connectors.In order to verify the proposed method,a reduced-scale specimen test was conducted,and single damage and multiple damage conditions were designed.The experiment results reflect that there is an obvious difference between the TDI of a damaged shear connector and that of an intact shear connector that can be as large as 39.2%.Therefore,the proposed method can effectively indicate the damage state and degree of the shear connector.The experiment results also validate that the damage of other shear connectors cannot influence the detection result in multiple damage conditions.Additionally,an antinoise performance analysis has been carried out by using the simulation results.It is suggested to maintain a signal-to-noise ratio larger than 40 dB so as to ensure the robustness of the proposed method.