基于索力响应面法的斜拉桥模型修正

Updating of Cable-stayed Bridge Model Based on Cable Force Response Surface Method

提出一种基于索力响应面的斜拉桥模型修正方法。利用多点约束法建立了斜拉桥一致多尺度有限元模型,在多尺度分析的基础上,以索力作为特征量,采用F检验法进行参数显著性分析,筛选显著性较高的参数作为输入响应,索力作为输出量,采用二次多项式法进行索力响应面方程拟合,并以实测索力为参照运用最小二乘法进行响应面模型修正。最后以实验室独塔斜拉桥为研究对象,进行了数值仿真验证,结果表明:该方法修正后参数的物理意义明确,修正后索力与实测索力吻合良好,且同时修正了正应力及竖向位移,降低了计算偏差,可进行多目标综合修正。

A cable-stayed bridge model updating method based on cable response surface was proposed in this paper.A multi-scale finite element model of cable-stayed bridge was established by using multipoint constraint method.Based on multi-scale analysis,with cable forces taken as the characteristic quantity,the structural correction parameters were selected and significance analysis was done by using F-test method.After the significant parameters were selected as the input response,and the cable forces were used as the output response,the response surface equations of cable forces were obtained by the quadratic polynomial method.The iterative correction in the response surface model was carried out by using the least square method based on the measured cable forces.Finally,in the case of the single tower cable-stayed bridge in the laboratory,numerical simulation was carried out.The results show that the physical meaning of the modified parameters is clear and the calculated cable forces of the modified model are in good agreement with the measured cable forces.The calculation errors of the principal stress and the vertical displacement are effectively reduced,and the multi-objective comprehensive correction is realized.