正则化Bouc-Wen模型的参数研究及其在金属阻尼器中的应用

Parametric study of the normalized bouc-wen model and its application in metallic dampers

针对经典Bouc-Wen模型中存在冗余参数的情况,介绍了一种无冗余参数的正则化Bouc-Wen模型。基于理论推导及编制的Matlab程序,对正则化Bouc-Wen模型各参数与其所描述的金属阻尼器滞回力学参数之间的关系进行了研究。采用局部敏感性分析方法基于两种不同的敏感性评价指标对正则化Bouc-Wen模型各参数的敏感性进行了分析。提出了基于改进模拟退火算法的参数拟合方法并进行试验验证。研究结果表明,金属阻尼器的初始弹性刚度kd及屈服力Fdy均由kx、kw、ρ三个参数共同决定,屈服后刚度k'd由参数kx决定,屈服位移udy由参数ρ决定,转向刚度ks与初始弹性刚度kd之间的相对关系由参数σ决定,弹塑性过渡段的圆滑度由参数n决定。正则化Bouc-Wen模型中的kw、ρ两个参数具有较高的敏感性,σ、kx、n三个参数具有较低的敏感性。改进的模拟退火算法能够有效实现对正则化Bouc-Wen模型的参数拟合,金属阻尼器试验滞回曲线与拟合曲线能够较好吻合。

Due to the parameter redundancy in the traditional Bouc-Wen model, a normalized form of the Bouc-Wen model was introduced. Then the relations between the parameters of the normalized Bouc-Wen model and the hysteretic parameters of the corresponding metallic damper were studied. A parameter sensitivity analysis was also conducted for the normalized Bouc-Wen model by using the local sensitivity analysis method based on two different sensitivity indices. A parameter fitting method was also proposed using a modified simulated annealing algorithm and verified by experiments. The results show that the initial elastic stiffness k d and the yield force F dy are determined by the parameters k x, k w and ρ in the normalized Bouc-Wen model, the post-yield stiffness k ′ d is determined by the parameter k x , the yield displacement u dy is determined by the parameter ρ , the relation between the shift stiffness k s and the initial elastic stiffness k d is determined by the parameter σ , and the smoothness of the transition from elastic to plastic response is determined by the parameter n . The parameters k w and ρ exhibit higher sensitivity, while σ , k x and n exhibit lower sensitivity. The modified simulated annealing algorithm is able to identify the parameters of the normalized Bouc-Wen model effectively, and the simulation hysteresis curves fit well with those by experiments.