基于岭估计和L曲线的损伤识别技术研究

摘要

In order to solve the reliability problem of structural damage equation,a damage detection method based on ridge estimation and L-curve was presented.Firstly,a structural damage equation based on modal strain energy sensitivity was described.Then,considering measurement noise easily making the damage equation be ill,the ridge estimation was utilized to solve the damage equation and L-curve is utilized to identify optimal ridge parameters.Finally, an improved ridge estimation method was proposed to enhance the identification precision.Simulation results demonstrated that the proposed ridge estimation and L-curve methods can detect structural damage locations and level with good accuracy,their quantitative detection results are obviously better than those of the basic ridge estimation and L-curve methods and the truncated singular value decomposition method.%为了解决结构损伤方程求解的可靠性问题，提出了基于岭估计和L曲线的损伤方程求解方法。首先描述了基于模态应变能灵敏度的结构损伤方程，然后考虑测量噪声等因素易造成病态的损伤方程问题，提出了采用岭估计求解结构的损伤方程，并利用 L 曲线确定最优的岭参数，最后建立了损伤估计值的修正方法。数值仿真结果表明，基于修正的岭估计和 L 曲线方法可以较为精确地识别出损伤的位置和程度，而且其定量识别结果明显好于基本的岭估计和 L 曲线方法以及一般的截断奇异值分解法。