【摘要】 针对大跨混凝土斜拉桥结构有限元模型修正,为了充分利用静动力试验数据,提出了一种基于多目标优化算法的模型修正方法。利用静力位移和动力模态频率等结构实测静动力响应构造修正目标函数,在灵敏度分析的基础上选择待修正参数,采用带精英策略的快速非支配排序遗传算法(NSGA-Ⅱ)对国内某混凝土斜拉桥有限元模型进行了多目标优化修正,得到了模型修正多目标优化问题的Pareto最优解集,并利用静动力实测数据对修正后的有限元模型进行了验证。结果表明:模型修正后不仅参与优化的静力位移和动力计算结果与实测值吻合良好,而且未参与修正的结构静动力响应也与实测值更加接近,混凝土斜拉桥采用这种基于多目标优化的静动力有限元模型修正方法能够取得较满意的效果,修正后的有限元模型能够精确全面的模拟实际结构。更多还原

【Abstract】 Aiming at finite element model updating for a long-span concrete cable-stayed bridge,a model updating method was proposed based on the multi-objective optimization to fully use the structure’s static and dynamic test data.The updating objective function was constructed using the structure ’s static displacements and dynamic modal frequencies,etc. actual measured data,parameters to be updated were chosen based on the sensitivity analysis. The finite element model of a certain concrete cable-stayed bridge in China was updated with multi-objective optimization using the non-dominated sorting genetic algorithm-II( NSGA-II) to obtain Pareto optimal solution set to the problem of finite element model updating with multi objective optimization. The modified finite element model was verified with the measured static and dynamic data. The results showed that not only the updated model’s static displacements and dynamic calculation results involved in the optimization agree well with the measured values,but also the updated model’s static and dynamic calculation results not involved in the optimization are closer to the measured values; this static and dynamic finite element model updating method for the concrete cable-stayed bridge based on multi-objective optimization has a satisfactory effect,and the updated finite element model can accurately and fully simulate the actual structure.更多还原