基于裂纹扩展阻力曲线的钢结构构件断裂行为评估模型  

Fracture behavior evaluation model for steel structural components based on crack extension resistance curves

作　　者：王元清[1] 周晖[1] 石永久[1] 武延民[2] 

机构地区：[1]清华大学土木工程系,土木工程安全与耐久教育部重点实验室,北京100084 [2]中冶集团中冶京诚工程技术有限公司,北京100053

出　　处：《清华大学学报（自然科学版）》2013年第5期595-600,共6页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50778102;51178244);清华大学黄廷芳信和优秀博士生基金资助项目

摘　　要：为准确预测钢结构构件的断裂破坏,提出了基于裂纹扩展阻力曲线的评估方法。基于前期开展的低温下结构钢材的裂纹尖端张开位移(CTOD)试验结果,采用试验数据回归和理论分析方法,对裂纹扩展阻力曲线的参数进行标定,并分析裂纹扩展阻力曲线形式与含裂纹钢构件断裂模式的关系。结果表明:当构件初始裂纹长度大于临界值且钢材裂纹扩展阻力曲线呈上凸形时,构件发生韧性断裂;当构件初始裂纹长度小于临界值且阻力曲线呈上凸形时,或当阻力曲线呈水平直线时,构件发生脆性断裂。本文理论模型计算的最大载荷点裂纹扩展量与试验实测值吻合较好,验证了理论分析的准确性,可应用于钢结构构件的防断设计。An evaluation approach based on crack extension resistance curves was developed to accurately predict fractures of steel structural components.The crack extension resistance curve parameters for structural steels were calibrated using data regression and theoretical analyses based on crack tip opening displacement（CTOD） tests at low temperature carried out earlier by the authors.The crack extension resistance curves are then related to the fracture modes of steel components with cracks.The results indicate that steel components with crack lengths longer than the critical size having apositively sloped crack extension resistance curve in steel material toughness will fracture in the ductile mode while those with crack lengths shorter than the critical size having apositively sloped resistance curve or having a horizontal resistance curve will fracture in the brittle mode.The crack extension length corresponding to the maximum load calculated by this theoretical model agrees well with the test results,validating that the theoretical analysis is accurate and can be applied in fracture resistant designs of steel structural components.

关 键 词：钢结构 裂纹扩展阻力曲线 裂纹尖端张开位移(CTOD) 脆性断裂 韧性断裂 

分 类 号：TU391[建筑科学—结构工程]