基于Hertz-Mindlin模型的稻草秸秆参数标定及显著性分析  

Parameter Calibration and Significance Analysis of Rice Straw based on Hertz-Mindlin Model

作　　者：龚凤 胡嫚[1] 鲍安红[1] 李丹 高涛 王春龙 GONG Feng;HU Man;BAO Anhong;LI Dan;GAO Tao;WANG Chunlong(College of Engineering and Technology,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学工程技术学院,重庆400715

出　　处：《西南大学学报（自然科学版）》2022年第12期186-196,共11页Journal of Southwest University(Natural Science Edition)

基　　金：重庆市技术创新与应用发展专项(cstc2019jscx-gksbX0118).

摘　　要：稻草秸秆具有环保无污染、绿色可再生、丰富易获得等优点,近年来逐渐发展为一种环保建筑材料,如稻草—混凝土复合砌块.为了准确获取制作稻草—混凝土复合砌块过程中稻草秸秆在钢模具内的接触参数大小,本文设计了稻草秸秆堆积室内试验,在此基础上采用Hertz-Mindlin(no slip)接触模型建立了稻草秸秆离散元模型,实现了稻草秸秆堆积过程与形态的模拟仿真.进一步通过设计Plackett-Burman试验、最陡爬坡试验、Box-Behnken试验对接触参数进行显著性分析,建立了休止角与显著性接触参数的二次多项式回归模型,并以物理试验测定的休止角作为响应目标,对显著性接触参数寻优标定.研究结果表明:稻草秸秆与稻草秸秆的静摩擦系数为0.43,滚动摩擦系数为0.24,碰撞恢复系数为0.28;稻草秸秆与钢板的静摩擦系数为0.20,滚动摩擦系数为0.15,碰撞恢复系数为0.30.其中,稻草秸秆与钢板的静摩擦系数、稻草秸秆与稻草秸秆的静摩擦系数、稻草秸秆与稻草秸秆的滚动摩擦系数对休止角影响最显著,而其余接触参数对休止角无显著性影响.结合物理试验将优化标定的接触参数进行仿真对比,表明仿真休止角与实测休止角无显著性差异,其相对误差仅为0.75%,验证了接触参数标定的准确性.研究成果可为进一步探究稻草秸秆在钢模具中的分布成型特征提供重要参考.Rice straw has the advantages of being environmentally friendly,non-polluting,green and renewable,abundant and easy to obtain.In recent years,it has gradually developed into an environmentally friendly building material,such as straw-concrete composite blocks.In order to accurately obtain the contact parameters of rice straw in the steel mold during the process of making rice straw-concrete composite blocks,this paper is based on the rice straw stacking test,using image processing technology,combining physical experiments and discrete element simulation to optimize the contact parameters.Firstly,the discrete element model of straw was established by using Hertz-Mindlin(no slip)contact model,and the simulation of straw stacking process and morphology were realized.Then,the Plackett-Burman test,the steepest climbing test and the Box-Behnken test were designed to analyze the significance of contact parameters,and a quadratic polynomial regression model was established for the angle of repose and significant contact parameters.Finally,the angle of repose determined by physical test was used as the response target,and the significant contact parameters were optimized and calibrated.The results show that the static friction coefficient between rice straws is 0.43,the rolling friction coefficient is 0.24,and the collision recovery coefficient is 0.28.The static friction coefficient between rice straw and steel plate is 0.20,the rolling friction coefficient is 0.15,and the collision recovery coefficient is 0.30.The static friction coefficient between rice straw and steel plate,the static friction coefficient between rice straw and rice straw,and the rolling friction coefficient between rice straw and rice straw have the most significant effects on the angle of repose,while the other contact parameters have no significant effects on the angle of repose.Combined with physical experiments,the optimized calibrated contact parameters are simulated and compared.It shows that there is no significant difference between the simul

关 键 词：稻草秸秆 复合砌块 堆积试验 离散元 参数标定 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术] S210.3[自动化与计算机技术—计算机科学与技术]