基于改进Bouc-Wen模型的防屈曲支撑参数拟合方法

Fitting method of buckling restrained brace parameters based on modified Bouc-Wen model

在经典Bouc-Wen模型的基础上,介绍了一种能更好地模拟防屈曲支撑材料塑性硬化及力学参数非对称性特点的改进Bouc-Wen模型。采用单参量变化法对改进Bouc-Wen模型的各项参数进行了敏感性分析,基于敏感性分析结果及目标函数最优解求解特点,给出了基于改进梯度下降法的参数拟合方法,并在参数拟合精度及拟合效率方面与遗传算法、粒子群优化算法进行了对比分析。通过防屈曲支撑的静力往复试验结果验证给出的参数拟合模型及参数拟合方法的有效性。结果表明,改进的Bouc-Wen模型能更好地模拟防屈曲支撑的滞回特性。相较于遗传算法、粒子群优化算法等参数拟合方法,改进的梯度下降法具有更高的参数拟合精度及拟合效率,并且能有效拟合改进Bouc-Wen模型的各项参数,防屈曲支撑拟合滞回曲线与试验滞回曲线有较高的吻合度。

Based on the classical Bouc-Wen model,an improved Bouc-Wen model is introduced,which can better simulate the plastic hardening and mechanical parameter asymmetry of buckling restrained brace.The sensitivity analysis of the parameters of the modified Bouc-Wen model is carried out by using the single-parameter variation method.Based on the sensitivity analysis results and the characteristics of solving the optimal solution of the objective function,the parameter fitting method based on the improved gradient descent method is given,and the parameters fitting accuracy and efficiency are compared with genetic algorithm and particle swarm optimization algorithm.The validity of the model and method is verified by the results of static reciprocating test of buckling restrained brace.The results show that the improved Bouc-Wen model can better simulate the hysteretic behavior of buckling restrained brace.Compared with the genetic algorithm,particle swarm optimization algorithm and other parameter fitting methods,the improved gradient descent method has higher parameter fitting precision and efficiency,and can effectively fit the parameters of the improved Bouc-Wen model.The fitting hysteresis curve of the buckling restrained brace has a high degree of coincidence with the experimental hysteresis curve.