混凝土Ⅰ型裂缝失稳扩展时临界有效缝长的数值研究  

Numerical Study on the Critical Effective Crack Length During the Instability Propagation of Type Ⅰ Crack in Concrete

作　　者：郑轶 王向东[1] 刘庆辉[1] ZHENG Yi;WANG Xiangdong;LIU QingHui(College of Mechanics and Materials,Hohai Univ.,Nanjing 211100,China)

机构地区：[1]河海大学力学与材料学院,南京211100

出　　处：《三峡大学学报（自然科学版）》2022年第4期45-50,共6页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金(51809164)。

摘　　要：混凝土的失稳断裂韧度是进行带裂缝混凝土结构裂缝稳定性分析的重要参数,计算失稳断裂韧度需要准确的临界有效缝长.基于虚拟裂缝模型,应用断裂力学经典理论中的最大拉应变断裂判据,推导出混凝土Ⅰ型裂缝失稳扩展临界有效缝长的计算公式;基于Loland损伤模型,应用能量守恒定律,推导出考虑损伤和断裂过程区的混凝土Ⅰ型裂缝失稳扩展临界有效裂缝缝长的计算公式.采用数值模拟实验得到的结果和推导得到的临界有效裂缝缝长的计算公式,计算临界有效缝长,进一步计算得到断裂韧度,该结果与柔度改变法计算结果吻合.说明用本文方法得到的临界有效缝长计算公式的合理性,据此进行断裂韧度计算是有效的,且新方法对于工程实际具有重要的参考价值.The concrete fracture toughness is an important parameter of the concrete structure with cracks.The critical effective crack length is needed for calculating the critical effective fracture toughness.First of all,based on Fictitious Crack Model,the critical formula of effective seam length of type Ⅰ crack is deduced according to the classical theory of fracture mechanics and maximum tensile strain failure criteria.Then,based on Loland damage model,a modified critical formula of effective seam length of type Ⅰ crack is deduced by using the law of conservation of energy,which considers the effects of damage and the fracture process zone.Based on the results of numerical simulation experiments and the derived formula,the critical effective fracture length and the fracture toughness are calculated.The results are consistent with the results of flexibility change method.It illustrates that the calculation formula in this paper is effective,which provides a new method for engineering practice.

关 键 词：混凝土 断裂过程区 临界有效缝长 损伤 断裂韧度 

分 类 号：TU528[建筑科学—建筑技术科学]