基于模态参数及BAS-PSO优化算法的软基水闸有限元模型参数修正方法

FINITE ELEMENT MODEL PARAMETER UPDATING OF SLUICES ON A SOFT FOUNDATION BASED ON MODAL PARAMETERS AND BAS-PSO OPTIMIZATION ALGORITHM

正确合理的有限元模型对于软基水闸结构健康监测及性能评估至关重要,但水闸有限元模型参数的不确定性使得建立的水闸有限元模型难以准确地反映水闸结构真实的动力学特性,该文结合模态参数和基于天牛须搜索算法的粒子群(BAS-PSO)优化算法,提出了一种软基水闸有限元模型参数修正方法。选择对水闸模态参数影响较大的弹性模量和密度作为待修正参数,建立反映软基水闸待修正参数和模态参数之间非线性关系的基于遗传算法的支持向量回归(GA-SVR)代理模型;提出基于GA-SVR代理模型计算模态参数与水闸振动模态参数之间相对偏差最小的目标函数,构建软基水闸有限元模型参数修正的最优化数学模型;提出一种BASPSO优化算法来求解最优化数学模型,克服了局部最优和收敛速度慢的问题。通过软基水闸物理模型实例表明,修正的有限元模型计算的模态参数与水闸识别模态参数在数值上比较吻合,该文方法合理可靠且具有良好的可行性,可为软基水闸有限元模型参数修正提供一条新思路。

A reliable finite element model(FEM)is crucial for the health monitoring and performance evaluation of sluices on soft foundations.Due to the parameter uncertainty,FEM is difficult to accurately reflect the true dynamic characteristics of the sluice.In this paper,we propose an FEM parameter updating method for sluices on soft foundations,which combines modal parameters and is based on the beetle antennae search particle swarm optimization(BAS-PSO)algorithm.The elastic modulus and density that have a great impact on the modal parameters of the sluice are selected as the parameters to be updated.A genetic algorithm support vector regression(GA-SVR)proxy model,which can reflect the nonlinear relationship between the updated parameters and the modal parameters of the sluice on the soft foundation,is established.An objective function based on the minimum relative deviation between the modal parameters identified by the measured response and the modal parameters calculated by the GA-SVR proxy model is proposed.The optimized mathematical model to update the FEM parameter of the sluice on the soft foundation is constructed.A BAS-PSO optimization algorithm is proposed to solve the optimization mathematical model,which overcomes the drawbacks of local optimization and slow convergence.The physical model of the sluice on the soft foundation shows that the modal parameters calculated by the modified FEM are numerically consistent with the vibration modal parameters of the sluice,and that the proposed method is reliable and feasible,providing a new idea for the FEM parameter updating of sluices on soft foundations.