基于内聚力单元的石拱桥数值模拟

NUMERICAL SIMULATION OF MASONRY BRIDGE ON COHESIVE ELEMENT

古石拱桥一般由块石砌筑而成,材料有明显的非匀质性,且古石拱桥在长期荷载作用下很容易产生累计变形改变拱圈几何形状,进而影响其结构受力,采用传统整体式有限元模型很难准确模拟古石拱桥的受力性能。因此,为精确模拟古石拱桥实际受力状态,分析承载力影响因素,采用参数化建模的方法建立两相数值模型,用内聚力单元模拟材料非线性,并通过自编程序引入初始缺陷。分析了几何参数及材料参数对拱桥承载能力和破坏模式的影响。结果表明几何参数与材料参数显著影响结构的承载能力和破坏模式,为石拱桥的设计及修复、加固工作提供依据。

Ancient stone arch bridges are generally built with block stones,the materials of which are with obvious heterogeneity.Moreover,the bridge is prone to cumulative deformation that changes the geometric shape of the arch ring under long-term loading,thereby affecting its structural stress.With traditional integral finite element models,it is difficult to accurately simulate the stress performance of the ancient stone arch bridge.A parameterized model⁃ing method is used to establish a two-phase numerical model to accurately simulate the actual stress state of the an⁃cient stone arch bridge and analyze the factors affecting its bearing capacity.The material nonlinearity is simulated through cohesive elements,and initial defects are introduced through a self-designed program.The influence of geo⁃metric and material parameters on the bearing capacity and failure mode of arch bridges is analyzed.The results indi⁃cate that geometric and material parameters significantly affect the bearing capacity and failure mode of the struc⁃ture,providing a basis for the design,repair,and reinforcement of stone arch bridges.