基于扩展有限元分析技术的古建木梁裂纹扩展仿真(英文)  

Crack Extension Simulation of a Chinese Ancient Wooden Beam Based on XFEM Technique

作　　者：周乾[1,2] 

机构地区：[1]故宫博物院,北京100009 [2]北京工业大学工程抗震与结构诊治北京市重点实验室,北京100124

出　　处：《科学技术与工程》2014年第24期272-275,280,共5页Science Technology and Engineering

基　　金：文化部科技创新项目(17-2009);国家自然科学基金项目(50878010,51278013)资助

摘　　要：古建木梁在外力作用下很容易产生水平裂纹。为保护古建筑,采用XFEM数值模拟方法,研究了水平荷载作用下古建木梁的裂纹扩展特性。基于木材材料特性,仅考虑木梁沿水平向产生裂纹,建立了含裂纹木梁的简化有限元模型。在顶部施加了水平位移荷载,研究了裂纹扩展过程中木梁应力、变形及裂缝的变化特征,讨论了不同因素对裂纹扩展特性的影响。结果表明:随着荷载步增大,木梁变形峰值增大,但表现不明显;木梁主应力峰值明显增大,且发生在裂尖附近;增大外荷载时,木梁应力峰值增大明显,其裂纹容易产生扩展;增大裂纹初始长度时,木梁受力性能变化不大。此外,采用有限元法中的XFEM技术可提高古建木梁裂纹扩展研究的效率,并进一步深入分析结构裂纹扩展失效机制,从而为古建筑保护提供有效参考。Chinese ancient wooden beams are easy to produce level cracks under loads.To protect Chinese ancient wooden buildings,crack extension characteristics of an ancient beam under level load were studied by XFEM technique.Based on properties of wood material as well as hypothesis that only level crack occurred on the beam,simplified XFEM （extended finite element method） of the ancient beam was built.Level load was applied to the model.Displacement,principle stress distributions of the model during course of crack extension were studied,and corresponding influence factors were also discussed.Results show that with the increase of load step,peak deformation value of the beam increases little,but its peak principle stress value increases obviously near end of the crack ; the increase of load leads to obviously increase of peak value of principle stress of the beam,however the increase of initial length of crack affects little to mechanical performances of the beam.Besides,XFEM technique is proved to be effective for analysis of crack extension of Chinese ancient wooden buildings.

关 键 词：古建木梁 裂纹扩展 破坏 数值模拟 XFEM 

分 类 号：TU366.2[建筑科学—结构工程]