新拌混凝土离散元参数的测量与标定  

Measurement and calibration of discrete element parameters of fresh concrete

作　　者：曹国栋[1] 谭韬 姜胜强[2] 邓代强 刘宇[1] 苏泓玮 CAO Guodong;TAN Tao;JIANG Shengqiang;DENG Daiqiang;LIU Yu;SU Hongwei(College of Civil Engineering,Xiangtan University,Xiangtan 411105,China;School of Mechanical Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学土木工程学院,湖南湘潭411105 [2]湘潭大学机械工程与力学学院,湖南湘潭411105

出　　处：《湘潭大学学报（自然科学版）》2024年第3期13-21,共9页Journal of Xiangtan University(Natural Science Edition)

基　　金：湖南省教育厅重点项目(22A0104)。

摘　　要：随着计算机技术的发展,可以采用仿真的方法来研究新拌混凝土的流变性能.离散元方法适合于新拌混凝土的大变形流动.颗粒的物性参数和接触参数的设定是模拟结果真实可靠的关键.在本研究中,将混凝土分为机制石和砂浆两相.首先测量了物性参数,包含密度、恢复系数、静摩擦系数和滚动摩擦系数.使用Hertz-Mindlin(no slip)接触模型表示粗骨料-边界和粗骨料-粗骨料之间的相互作用,并通过休止角的实验进行了验证;采用Hertz-Mindlin with JKR接触模型来描述粗骨料-砂浆、砂浆-砂浆、砂浆-边界之间的相互作用,用坍落度实验对JKR参数进行了标定,并采用响应曲面法确定了最佳的参数组合值.最后通过L型箱试验对新拌混凝土的离散元仿真方法进行了验证.With development of computer technology,the numerical method is used to investigate the rheological behavior of fresh concrete.Discrete Element Method is suitable for the larger deformation of fresh concrete.The accuracy of the physical and contact parameters of the particles is key to the reliability of the simulation results.In this study,the concrete was divided into two phases:Mechanism stone and mortar.The physical parameters such as density,recovery coefficient,coefficient of static friction and coefficient of rolling friction were firstly measured.Hertz-Mindlin(no slip)model was used to represent interactions of the coarse aggregate-boundary or coarse aggregate-coarse aggregate,and was verified by experiment with angle of repose.Hertz-Mindlin with JKR contact model was used to describe interactions of coarse aggregate-mortar,mortar-mortar or mortar-boundary,the JKR parameters were calibrated using slump experiment and the optimal parameter combination were determined using the response surface method.Finally the discrete element simulation method of fresh concrete was validated by L-box test.

关 键 词：新拌混凝土 接触模型 休止角 二阶回归模型 

分 类 号：TU398[建筑科学—结构工程]