波形钢腹板-钢管混凝土翼缘组合梁桥疲劳性能的多尺度有限元分析

Multi-scale Finite Element Analysis of Fatigue Property Composite Girder Bridges with Corrugated Steel Webs and Concrete Filled Steel Tubes

对波形钢腹板-钢管混凝土翼缘组合梁进行了多点约束界面连接及多尺度有限元建模,通过计算分析和理论公式对比,验证了疲劳寿命预测精度和计算分析效率。采用多尺度模型对波形钢腹板-钢管翼缘连接部位应力特性进行了分析,比较了波形角以及波形转角曲率半径与波形高度比值对连接部位应力特性的影响。结果表明:采用多尺度模型可在不影响疲劳寿命预测精度的前提下,较为有效地提高波形钢腹板-钢管组合梁疲劳分析的计算效率,其计算分析时间比精细化模型可节约28.9%,而寿命预测相对误差可控制在2%以内;对于梁结构建模,采用多尺度模型计算分析时间比精细化模型可节约40.7%,而寿命预测相对误差可控制在5%以内;多尺度模型模拟连接部位主应力分布规律与精细化模型一致,最大主应力值相对误差在5%以内;该方法可较好地实现对波形钢腹板与钢管混凝土翼缘连接部位不利应力状态的模拟,可为波形钢腹板-钢管混凝土翼缘组合梁的相关疲劳损伤分析提供参考。

The finite element models were developed for composite girders with corrugated steel webs and concrete filled steel tubes using multipoint constraint and multi-scale modeling.The prediction accuracy and calculation efficiency of adopted finite element models were verified through a comparison with theoretical formulas.Based on the multi-scale model,the stress characteristics of connecting parts joining the corrugated steel webs and the concrete filled steel tubes were analyzed.A comparison was made for the prediction results influenced by the corrugation angle and the ratio of corrugation bending radius to corrugation height.The results show that the use of multi-scale model can effectively promote the calculation efficiency withoutaffecting precision of fatigue life prediction as a precondition.28.9%less calculation time and 2%prediction relative error can be achieved in multi-scale model with respect to refined model.For macro girder model,40.7%less calculation time and 5% prediction relative error can be attained in multi-scale model.The adverse stress condition of connecting parts between the corrugated steel webs and the concrete filled steel tubes can be simulated accordingly.The resultant maximum principal stress relative error is within 5%,and the method can simulate adverse stress behavior of connecting part between corrugated webs and concrete filled steel tubes.Thus,the analytical results can be taken as a reference for damages of composite girder bridges with corrugated steel webs and concrete filled steel tubes.