基于响应功率谱灵敏度分析的幕墙拉索损伤检测

幕墙拉索是重要的工程构件,为解决幕墙拉索的损伤检测问题,从弦的强迫振动方程出发,建立了其相应的有限元运动方程。将幕墙拉索的局部损伤模拟为弦单元面积的减少,利用随机振动的虚拟激励法,得到平稳随机激励下结构响应的功率谱密度函数对弦单元面积的灵敏度,采用有限元模型修正实现幕墙拉索的损伤识别。数值算例表明,仅利用有限的几个传感器的频域数据,就能够较好地识别幕墙拉索损伤,并且对模拟的人工噪声不敏感,具有一定的工程实用前景。

Damage Identification of Curtain Wall Cable Based on Sensitivity Analysis of Response Power Spectral Density

Curtain wall cable is an important engineering structure. Aiming at the damage detection of curtain wall cable, finite element method was used for the forced vibration analysis of string structures. The dynamic response sensitivity with respect to the physical parameter, such as elemental cross-sectional area, was derived. The sensitivity of the response power spectral density with respect to elemental cross-sectional area under stationary random excitations is obtained using pseudo excitation method. Then finite element model updating method is adopted to identify the curtain wall cable damage. Numerical simulation shows that satisfactory identification results can be obtained from the power spectral density of response data of several accelerometers and the proposed method is insensitive to the measurement noise. It has the potential for practical application.