水泥混凝土路面传力杆系统极限承载力的扩展有限元分析

针对超载引起的水泥混凝土路面传力杆系统的早期损坏问题,在多工况道路整体结构三维有限元分析的基础上,基于扩展有限元方法与子模型技术,对传力杆周围混凝土的承载力极限开裂过程进行了数值模拟。计算给出了传力杆周围混凝土材料内裂纹萌生、扩展及最终的破坏形式,并设计足尺试验对数值模拟结果进行验证,对比结果表明两者在加载点荷载-位移曲线与裂纹断裂模式上吻合较好。根据该文的研究可以发现,采用扩展有限元法与子模型技术相结合的方式,能够快速、准确地计算传力杆系统的极限承载力,进而反推出水泥混凝土路面缩缝结构的临界车辆轴载。同时该文的研究方法为解决混凝土结构局部应力集中区域的开裂、破坏过程行为研究提供了一种可行性数值研究手段。

Extended finite element analysis of ultimate load-bearing capacity for dowel bar system in cement concrete pavement

In order to analyze the premature damage of dowel bar system in jointed concrete pavement induced by overload, the extended finite element method (short for XFEM) coupled with submodeling method were employed to simulate the fracture process of concrete around the dowel bar under loading. This coupling method is based on 3-D finite element analysis which simulates the whole concrete pavement structure. The initialization and evolution of the cracks around the dowel bar in the inner concrete could be monitored in model simulation and full-scale experiment. Results show that the loading-displacement curves in the loading position and fracture mode of crack between the numerical simulations coincide well with full-scale experiment. And the coupling XFEM with submodeling method is an efficient and accurate method to calculate the ultimate bearing capacity of dowel bar. Furthermore, the critical axle load could be back-calculated based on the former analyzing results. This research provides a valuable numerical analysis method to simulate the fracture process in stress concentration region of the concrete structure.