轮迹横向分布对钢桥面板疲劳应力幅的影响

Influence of Wheel Trace Transverse Distribution on Fatigue Stress Ranges of Steel Deck

为了对正交异性钢桥面板考虑轮迹横向分布影响时疲劳应力谱的简化计算提供参考,以港珠澳大桥正交异性钢桥面板为例开展研究。在对比分析国内外轮迹横向分布研究成果的基础上,采用ANSYS有限元软件建立实桥疲劳控制梁段三维仿真分析模型,研究了3种典型轮迹横向分布模型对疲劳易损细节应力幅的影响。研究结果表明:考虑轮迹横向分布的影响计算等效应力幅时,可仅考虑轮迹横向最不利位置所在车道的轮载贡献;不同易损细节之间折减系数的波动随轮迹分布模型集中程度的增加而增加;轮迹横向分布对等效应力幅的影响随易损细节位置至顶板距离的增加而增加;等效应力幅折减系数可取为0.9。

To provide reference for the simplified calculation of fatigue stress spectra of ortho‐tropic steel deck considering the influence of w heel trace transverse distribution ,the orthotropic steel deck of the Hong Kong‐Zhuhai‐Macao Bridge was cited as an example and was studied .Based on the comparative analysis of the foreign and domestic research findings of the w heel trace trans‐verse distribution ,the three‐dimensional simulation analysis models for the fatigue control girder segments of the actual bridge were built up by the finite element software ANSYS and the influ‐ences of 3 types of the models of the typical w heel trace transverse distribution on the stress ranges of vulnerable fatigue details were studied .The results of the study indicate that as the equivalent stress ranges are calculated ,considering the influence of the w heel trace transverse distribution , the contribution of the w heel loading on the lanes w here the most unfavorable positions of the wheel trace transverse distribution are located may be considered only .The fluctuation of the re‐duction factor of the different vulnerable fatigue details increases with the increase of the concen‐tration of the wheel trace transverse distribution models .The influence of the wheel trace trans‐verse distribution on the equivalent stress ranges increases with the increase of the distances from the vulnerable fatigue details positions to the top plate and therefore ,the reduction factor of the equivalent stress ranges can be taken as 0 .9 .