基于Tanaka-Mura模型的正交异性钢桥面板微裂纹萌生扩展寿命的研究

Study on Microcrack Initiation and Propagation Life of Orthotropic Steel Bridge Deck Based on Tanaka-Mura Model

采用三维Voronoi图在正交各向异性钢桥面板盖板-U肋焊接节点细晶粒热影响区建立晶体代表体积单元模型(RVE),考虑晶粒随机取向,生成晶体多滑移带模型。根据Tanaka-Mura位错滑移模型,用Python编写了疲劳裂纹萌生扩展脚本,计算微裂纹萌生扩展寿命。以安庆长江公路大桥为研究对象,计算其正交各向异性钢桥面板盖板-U肋焊接节点疲劳微裂纹萌生扩展寿命。结果表明该方法可有效分析正交异性钢桥面板微裂纹萌生扩展寿命。

The three-dimensional Voronoi diagram was used to establish the crystal representative volume element model( RVE) in the fine grain heat-affected zone of the orthotropic steel bridge deck cover-U rib welded joint.Considering the random orientation of grains,the crystal multi-slip band model was generated.Based on the Tanaka-Mura dislocation slip model,a script for fatigue crack initiation and propagation was written in Python,and the micro-crack initiation and propagation life was calculated.Taking Anqing Yangtze River Highway Bridge as the research object,the fatigue micro-crack initiation and propagation life of the orthotropic steel bridge deck cover-U rib welded joint was calculated.The results indicate that this method can effectively analyze the initiation and propagation life of microcracks in anisotropic steel bridge decks.