|针对苹果采后管道输送过程中果实碰撞损伤较大的问题，对苹果在输送管道内下落的运动规律及管道输送装置最优参数组合进行研究。应用Ansys Workbench LS-DYNA软件进行苹果下落动力学仿真分析，并建立苹果在输送管道内下落的动力学模型，理论分析与仿真模拟相结合探究苹果在管道内的运动规律；以输送管道曲率半径、苹果果径和缓冲材料类型为因素，以苹果与果筐碰撞时的等效应力为试验指标，进行单因素仿真试验和3因素3水平正交试验，获得管道输送装置最优参数组合；应用对标试验对苹果输送过程仿真结果的可靠性进行验证。单因素试验结果表明：随着输送管道曲率半径的增大，苹果与果筐碰撞位置越靠近筐底，苹果与果筐碰撞时的等效应力逐渐增大；随着苹果果径的增大，苹果与果筐碰撞时的等效应力逐渐增大；缓冲材料对缓冲效果的影响顺序为，珍珠棉>EVA泡棉>保温保湿带>气泡膜>瓦楞纸衬垫。正交试验结果表明：3个因素对响应值影响均显著，显著程度由大到小为输送管道曲率半径>缓冲材料类型>苹果果径。当苹果果径为75 mm时管道输送装置最优参数组合为输送管道曲率半径200 cm、缓冲材料为珍珠棉，苹果与果筐撞击时的等效应力最小为26.48 kPa，管道输送装置对苹果保护作用最好。建立的苹果管道下落模型能准确模拟苹果下落的真实过程，可为设计与优化苹果管道输送装置提供依据。
|关键词: 苹果 管道输送 动力学仿真 等效应力
|基金项目:河北省现代农业产业技术体系苹果创新团队现代果园装备与智能化项目（HBCT2023120202）；财政部 农业农村部 国家现代农业产业技术体系建设项目（CARS-27）
|Analysis and simulation of the apple falling process in pipeline transportation system
ZHANG Kuo1, LIU Hongjie1,2, LI Jianping1,2*, LIU Shuteng1, LI Shaobo1, XU Shuo1
|(1.College of Mechanical and Electrical Engineering, Hebei Agricultural University, Baoding 071001, China;2.Hebei Province Smart Agriculture Equipment Technology Innovation Center, Baoding 071001, China)
|In response to the significant issue of fruit collision damage during the post-harvest pipeline transportation of apple， research is conducted on the motion laws of apples falling within the pipeline and the optimal parameter combination for pipeline transportation devices. ANSYS Workbench LS-DYNA software was used to analyze the dynamic simulation of apple falling， and a dynamic model of apple falling within the pipeline was established. A theoretical analysis was combined with simulation to explore the motion laws of apples within the pipeline. Taking the curvature radius of transportation pipelines， the diameter of apples， and the type of buffering materials as factors， single-factor simulation experiments and a 3-factor and 3-level orthogonal experiment were conducted with the equivalent stress between apples and fruit baskets during the collision as the experimental indicator to obtain the optimal parameter combination for the pipeline transportation devices. Benchmark tests were applied to validate the reliability of the simulated apple transportation process. The results of single-factor experiments showed that： With the increasing of the curvature radius of the transportation pipelines， the positions of collisions between apples and fruit baskets moved closer to the bottom of the baskets， and the equivalent stress during collision increased gradually. With the increasing of the diameter of apples， the equivalent stress during collision also increased gradually. The impact of buffering materials on the buffering effect in descending order was as follows： pearl cotton>EVA foam>thermal insulation and moisture retention belt>bubble film>corrugated paper lining. The results of the orthogonal experiments showed that all the three factors had a significant impact on the response value， with the curvature radius of transportation pipelines having the greatest impact， followed by the type of buffering materials， and then the diameter of apples. When the diameter of apples was 75 mm， and the optimal parameter combination for the pipeline transportation devices was the curvature radius of 200 cm with pearl cotton as the buffering material， resulting in the minimum equivalent stress of 26.48 kPa during the collision between apples and fruit baskets. In conclusion， the pipeline transportation devices provided the best protection for apples. The model established for apple falling in pipelines accurately simulated the real falling process of apples， which can provide a scientific basis for designing and optimizing apple pipeline transportation devices.
|Key words: apple pipeline transport dynamic simulation equivalent stress