砌块墙体开裂过程数值模型及模拟分析

Numerical Model and Numerical Simulation of the Masonry Wall Fracture Process

选取剪压复合状态下的砌块墙体为研究对象,基于损伤力学与断裂力学理论,采用简化的分离式建模方法和可考虑组合块材之间接触界面粘结强度、损伤演化与摩擦滑移的内聚力界面模型,对砌块墙体开裂全过程进行数值模拟。讨论了3种迭代算法,对影响抗剪性能与开裂模式的主要因素,包括顶部竖向荷载、墙体高宽比等进行了探讨,并与汶川地震建筑震害进行了对比分析。研究结果表明:数值模拟位移场较好地反映了顶部竖向荷载、高宽比对开裂荷载与开裂模式的影响;数值模拟方法可较为精确地反映裂缝的萌生、扩展、贯通整片墙体的全过程,模拟结果与汶川地震建筑震害吻合较好。本文研究方法及结论对于准确模拟砌块墙体开裂的非线性过程、结构可靠性分析具有借鉴意义。

Based on damage mechanics and fracture mechanics theory,the block masonry walls subjected to compressive and lateral loads were selected as research subject,and the numerical simulation of the fracture progressing in the walls was carried out by adopting the simplified micro-modeling technique and the cohesive surface model in which the bonding strength,damage and slip between the interactive interfaces were taken into account.Three iterative algorithm were discussed,and the main factors related to the shear strength and fracture patterns,namely the compressive loads,aspect ratios and mortar strength,were analyzed.In addition,the numerical simulation results were compared with buildings damaged in Wenchuan earthquake.The results indicted that compressive loadings and aspect ratios change the cracking loads and fracture patterns significantly,and the mortar strength plays vital parts in the integral working performance.The simulation can accurately reflect the crack initiation,propagation until rupture through the whole wall,and the results are in good agreement with buildings damaged in Wenchuan earthquake.The method and conclusion can provide beneficial references for in-depth numerical simulation of fracture process in masonry wall and structural reliability analysis.