基于巴西劈裂试验的混凝土细观本构模型参数估计方法  

Microparameter Estimation Method of Concrete Micro-constitutive Model Based on Brazilian Test

作　　者：李守巨[1] 王颂[1] 王志云 LI Shouju1 , WANG Song1 , WANG Zhiyun2(1. State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, Liaoning 116024, China;2. College of Ocean and Civil Engineering, Dalian Ocean University, Dalian, Liaoning 116023, Chin)

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116024 [2]大连海洋大学海洋与土木工程学院,辽宁大连116023

出　　处：《山东科技大学学报（自然科学版）》2018年第4期49-57,共9页Journal of Shandong University of Science and Technology(Natural Science)

基　　金：国家重点基础研究发展计划项目(2015CB057804);国家自然科学基金项目(11572079);工业装备结构分析国家重点实验室开放基金项目(S14206)

摘　　要：通过力学性能试验确定细观参数取值是离散单元法进一步应用的关键问题。选取5个控制材料宏观响应的细观本构模型参数,建立混凝土材料巴西劈裂试件二维颗粒流程序(particle flow code in two-dimensions,PFC^(2D))计算模型,提出了一种细观参数的估计方法。假定试样的宏观响应与细观参数间为近似线性关系。根据已有研究成果,给出一组细观参数的初始值,利用线性回归得到细观参数对宏观响应的回归系数,建立细观参数与宏观响应的映射关系。定义目标函数为宏观响应的计算值与试验观测值的均方差最小,求解一个约束优化问题,得到细观参数的估计值。以C35混凝土巴西劈裂试验为例进行了模拟,结果表明根据估计的细观参数模拟得到的荷载-位移曲线与实际试验曲线吻合较好,验证了方法的有效性。The determination of microparameters through mechanical tests is the key problem to the further application of discrete element method.In this paper,aparticle flow code in two-dimensions（PFC^2D）simulation model of concrete Brazilian test specimen was established by selecting five microparameters of the concrete micro-constitutive model which could control the macroscopic response of the specimen,and a microparameter estimation method was proposed.With the assumption that the macroscopic response of the specimen has an approximate linear relationship with the five microparameters,the mapping relationship between microparameters and macroscopic response was established by giving a set of initial values of microparameters and by obtaining the regression coefficients of microparameters to macroscopic response based on the existing research.The objective function was defined as the minimumof mean square deviation of the calculated and observed values of macroscopic response,and the estimated values of microparameters are obtained by solving a constrained optimization problem.With the Brazilian test of C35 concrete as an example,the estimated parameters were simulated.The result shows that the load-displacement curve of Brazilian test and and that of PFC^2D simulation agree perfectly,which validates the effectiveness of the method proposed.

关 键 词：混凝土 巴西劈裂试验 离散单元法 颗粒流程序 细观参数 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]