摘要
为获取装配式建筑用混凝土的仿真模型和接触力学参数,采用颗粒离散单元法,基于对此种混凝土的坍落度试验结果,实现对浇筑预制构件的新拌混凝土进行模拟与接触力学参数的标定。在对混凝土建模的过程中考虑到混凝土颗粒之间的黏结力,用JKR黏结模型对混凝土颗粒进行建模,以JKR表面能的大小表征混凝土间的黏度效果,以影响混凝土坍落时形态和坍落后物料堆积高度为结果变量,以预制构件用混凝土坍落度试验的真实测量值为目标建立三维离散元分析模型。选取砂浆-砂浆、砂浆-石灰石、石灰石-石灰石、砂浆-壁面、石灰石-壁面之间的静摩擦因数、滚动摩擦因数和JKR表面能的15个参数作为研究对象,采用控制变量法改变单一参数的大小,确定影响此种混凝土坍落度试验中混凝土形态的显著参数,并采用响应曲面法确定显著参数的最佳组合值。以本研究标定参数模拟的混凝土与实际预制构件混凝土之间的坍落度试验数据相对误差在允许范围内,该研究标定的混凝土离散元模型和接触力学参数对混凝土布料设备及预制构件研究具有重要意义。
In order to obtain the simulation model and contact mechanics parameters of concrete used in prefabricated buildings,it adopted particle discrete element method to realize the simulation and calibration of contact mechanics parameters of freshly mixed concrete of cast prefabricated members based on the slump test results of this kind of concrete.In the process of the concrete modeling,considering the cohesive force between the concrete particles,JKR bond model was adopted to carry out the modeling of concrete particles,and the size of JKR surface energy was used to characterize the viscosity effect between the concrete.Later,the concrete slump form and material accumulation height after slum were regarded as result variables,and the real measured value of the prefabricated concrete slump test was used as the target for the establishment of three-dimensional discrete element analysis model.The static friction factor,rolling friction factor and JKR surface energy between mortar-mortar,mortar-limestone,limestone-limestone,mortar-wall surface,limestone-wall surface as well as 15 parameters JKR surface energy were selected as the research object,and the control variable method was used to change the size of single parameters and determine the significant parameters of concrete form in such concrete slump test,and at last,the response surface method was used adopted determine the optimal combination value of significant parameters.The relative error of slump test data between concrete simulated by the calibration parameters in this study and concrete of actual precast members is within the allowable range.Therefore,the concrete discrete element model and contact mechanics parameters calibrated in this study are of great significance to the research on the concrete pavement equipment and prefabricated parts.
作者
张珂
于天行
于文达
邹德芳
张世英
ZHANG Ke;YU Tianxing;YU Wenda;ZOU Defang;ZHANG Shiying(School of Mechanical Engineering,Shenyang Jianzhu University,Shenyang 110168,China)
出处
《混凝土》
CAS
北大核心
2020年第8期46-50,55,共6页
Concrete
基金
国家重点科技支撑计划(2017YFC0704003)
辽宁省自然基金指导计划(20180551119)
辽宁省教育部普通计划基金(LJZ2017031)
沈阳建筑大学基金(2017016)。
