基于内聚力模型的混凝土受拉断裂数值模拟与概率本构模型  

Cohesive model-based numerical simulation and probabilistic constitutive modeling of concrete tensile fracture

作　　者：郭文华[1] 冶桐杰 陈定市 GUO Wenhua;YE Tongjie;CHEN Dingshi(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《中南大学学报(自然科学版)》2025年第2期586-597,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52078489);中南大学中央高校基本科研业务费专项资金资助项目(2023ZZTS0373)。

摘　　要：提出一种高效的混凝土多边形随机骨料生成算法,基于内聚力模型研究混凝土的细观断裂行为,并建立混凝土细观受拉概率本构模型。首先,采用Monte Carlo方法建立细观混凝土结构模型,并采用射线法判断多边形之间的干涉关系。其次,编制全局内聚力单元插入程序,基于大量细观混凝土骨料模型的断裂数值模拟探究混凝土细观尺度断裂行为,并对模拟结果进行试验验证。最后,研究骨料体积分数和加载速率对混凝土断裂行为的影响,基于大量试件计算结果建立混凝土细观受拉概率本构模型。研究结果表明:采用射线法可有效提升随机多边形骨料的生成效率和投放体积;建立的混凝土细观概率力学本构模型能够反映骨料随机性导致的混凝土本构曲线变异性;混凝土抗拉强度随着骨料体积分数增加而呈现线性下降,但混凝土弹性模量有所增加;混凝土的抗拉强度随加载速率增加而明显提升。A novel and efficient concrete random polygonal aggregate generation algorithm was proposed,the mesoscopic fracture behavior of concrete was explored based on the cohesive zone model,and a mesoscale probabilistic constitutive model for concrete under tension was established.Firstly,the mesoscale aggregate model was established by using Monte Carlo methods,and ray method was used to assess interference among polygons.Secondly,a global cohesive element insertion program was developed to explore the mesoscale fracture behavior of concrete through numerical simulation of a large number of random aggregate models,and the simulation results were experimentally verified.Finally,the impact of aggregate content and loading rate on the fracture behavior of concrete was analyzed,and a probabilistic mesoscale constitutive model for concrete under tension was established through statistical analysis of numerous test calculations.The results show that the use of the ray method effectively improves the efficiency and packing volume of random polygonal aggregates.The established mesoscale probabilistic mechanics constitutive model for concrete can reflect the variability in the concrete constitutive curves caused by the random arrangement of the aggregates.The tensile strength of concrete decreases linearing with the increase of the aggregate volume fraction,whereas the modulus of elasticity of concrete increases.The tensile strength of concrete increases significantly with the increase of the loading rate.

关 键 词：混凝土 细观层次 随机骨料 内聚力模型 断裂行为 

分 类 号：TU528[建筑科学—建筑技术科学] U444[建筑科学—桥梁与隧道工程]