摘要
利用CMT8102微机控制材料试验机对豌豆、玉米、小麦、绿豆进行了加载-卸载试验,得到了4种谷物籽粒的载荷-压痕深度曲线。在谷物籽粒弹塑性力学性能研究中引入Venkatesh反向运算法则,计算出了4种谷物籽粒的弹性模量、屈服应力、硬化指数、接触刚度、最大接触面积等力学特性参数;把得到的弹性模量、屈服应力理论值添加到Abaqus的材料属性模块,对4种谷物籽粒的压入过程进行模拟仿真,得到了压痕形貌图和仿真曲线。仿真和试验曲线拟合结果说明了仿真的有效性,并且验证了Venkatesh反向运算法则在谷物籽粒材料特性研究中的准确性;压痕形貌图说明谷物籽粒具有弹塑性。研究还表明谷物籽粒硬度与应变硬化指数、最大等效接触应力、残余应力和屈服应力呈正比,与应力集中区域呈反比。
By using CMT8102 testing machine,the loading-unloading experiments for pea,corn,wheat and mung bean were conducted and the loading-indentation depth curves of grain were studied.The Venkatesh reverse operation rule was introduced to the study of elastic-plastic mechanics performance of grain to calculate the modulus of elasticity,yield stress,hardening index,contact stiffness,maximum contact area and other mechanical parameters of cereal grain.The obtained elastic modulus and the theoretical value of the yield stress has been added to the material properties module of abaqus.The pressing process of four kinds of cereal grain has been simulated and the indentation topography and the simulation curve were reported.The simulation and experimental curve was fitting,and the results illustrated the validity of the simulation.It is also verified the accuracy of using Venkatesh reverse operation rule in the study of material properties of cereal grain.The indentation morphology diagram illustrated that the cereal grains have elastic-plastic properties.The study also illustrated that grain hardness is proportional to the stiffness index,the maximum equivalent contact stress,residual stress and yield stress,and is inversely proportional to the area of stress concentration.The results of this research provide reference basis for the micro-mechanics of grain,and provide relevant measure for the processing,storage,transportation and breeding of cereal grain.
出处
《麦类作物学报》
CAS
CSCD
北大核心
2015年第4期563-568,共6页
Journal of Triticeae Crops
基金
干旱生境作物学国家重点实验室培养基地开放基金项目(GSCS-201209)
国家自然科学基金项目(51365003)
关键词
农业工程
谷物
试验
仿真
Agricultural engineering
Grains
Experiment
Simulation
