随机共振与响应灵敏度相结合的结构损伤检测方法

为了解决强噪声背景环境下的结构损伤识别问题,提出了一种基于非线性降噪和损伤定位相结合的两步法.第一步将结构的激励响应和背景噪声通过非线性随机共振系统进行处理,降低背景噪声的干扰以突出响应;第二步将结构的局部微小损伤模拟为单元弹性模量的减少,求得响应信息对单元弹性模量的灵敏度,据此对结构单元弹性模量进行修正,从而实现结构损伤的定位.数值算例表明,该方法在50%噪声水平环境下,能较好地实现损伤定位,单一损伤识别误差率不超过0.2%,多损伤识别的误差率不超过0.5%. 

Structure Damage Detection Method Based on Adaptive Stochastic Resonance Technology and Response Sensitivity Method

In order to solve the structural damage identification problem in strong noise environment, a two-step approach based on nonlinear denoising and damage location was proposed. In the first step, structural excitation response and background noise are processed through the nonlinear stochastic resonance system for enhancing the response signal. In the second step, local minor damage is defined as Young's modulus reduction, and the sensitivity of responses to the unit Young's modulus is worked out. Then the Young's modulus is revised to locate the damage in the structure. Numerical examples show that this method can well realize structural damage location under 50% background noise level, with the identification error rate being less than 0.2% for single damage and less than 0.5% for multiple damage.