荸荠冲击损伤有限元仿真分析及试验  

Finite element simulation and experiment of impact damage of water chestnuts

作　　者：张国忠[1,2] 李子涵 刘婉茹 张清洪 陈立明 裴蕾 刘浩蓬 ZHANG Guozhong;LI Zihan;LIU Wanru;ZHANG Qinghong;CHEN Liming;PEI Lei;LIU Haopeng(College of Engineering,Huazhong Agricultural University,Wuhan 430070,China;Key Laboratory of Agricultural Equipment in Midlower Yangtze River,Ministry of Agriculture and Rural Affairs,Wuhan 430070,China)

机构地区：[1]华中农业大学工学院,武汉430070 [2]农业农村部长江中下游农业装备重点实验室,武汉430070

出　　处：《农业工程学报》2025年第4期40-49,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家特色蔬菜产业技术体系专项资助项目(CARS-24-D-02);湖北省高等学校优秀中青年科技创新团队计划项目(T201934)。

摘　　要：荸荠机械采收及采后加工过程中常面临采收机械与荸荠间冲击而产生碰撞损伤等问题,为此采用Ansys软件开展荸荠冲击损伤的有限元仿真分析,以期获取提高荸荠机械采收与采后处理质量的途径与方法。根据试验测量荸荠本征参数,以线性弹塑性和主应变失效耦合模型建立荸荠材料模型,通过跌落试验标定并验证了模型参数,开展三因素三水平全因子杆条碰撞仿真试验探究跌落高度、碰撞接触面直径、碰撞材料对荸荠损伤的影响,并以考虑淤伤软化和破裂的损伤易感性评价标准建立了损伤易感性经验公式。测量得到荸荠果肉弹性模量、屈服强度、切线模量分别为7.916、0.586、4.554 MPa,主应变失效值为0.098,以失效网格体积和超过0.60 MPa应力区间体积对其冲击损伤分布进行模拟,淤伤体积、破裂体积及耗散能量与试验相对误差分别为7.18%、8.98%、6.62%,表明模型可用于描述荸荠在冲击载荷下的力学特性、破裂现象和能量耗散;杆条冲击试验结果表明,荸荠跌落高度与损伤易感性呈现线性增加关系,碰撞接触材料弹性模量对其损伤有显著影响,接触直径对损伤影响与接触材料有关,与结构钢碰撞时,损伤随直径增加出现先增大后减小现象,与PVC和橡胶碰撞时,损伤随接触直径增大而减小。研究结果可为荸荠机械化收获质量和采后处理技术与装备研究提供参考。Water chestnuts are aquatic root vegetables in the Asian areas.However,the collision damage can often occur in the mechanical harvesting and post-harvest processing of water chestnuts.In this study,a finite element simulation was conducted on the impact between harvesting machinery and water chestnuts using Ansys software.The impact damage to water chestnuts was identified to enhance the quality of mechanical harvesting and post-harvest treatment.A principal strain failure model was also adopted to accurately simulate the energy dissipation during collision,rather than the existing elastoplastic model.Initially,the average size of the water chestnut was measured using three-dimensional scanner.An appearance model was also created after scanning the samples.Three sections were then divided into:peel,pulp,and top bud.Uniaxial compression tests were conducted to measure and calculate the intrinsic parameters of the flesh and peel of the water chestnut.A comprehensive model of water chestnut was established after selection,thus culminating in the selection of a linear elastoplastic and principal strain failure coupling model.The parameters were calibrated and verified by slab drop tests at three heights.A systematic analysis was also made on the evolution of stress,energy,and rupture of the coupled model during drop.The screening device of the harvester also impacted the collision damage to water chestnuts.A simplified rod model was developed to investigate the impact of collision on the water chestnuts under various conditions.To this end,a three-factor,three-level and full-factor collision simulation test was conducted in the fall heights of 200,400,and 600 mm,collision contact surface diameters of 16,20,and 24 mm,and collision materials of structural steel,PVC,and rubber.A three-factor,three-level full-factor rod collision simulation test was also to assess the damage susceptibility of water chestnut to bruising,softening,and rupture.The analysis of variance(ANOVA)was employed for the empirical formula of damage s

关 键 词：荸荠 机械损伤 损伤模型 有限元 杆条 

分 类 号：S225.4[农业科学—农业机械化工程]