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Discrete element modeling and parameter calibration of safflower biomechanical properties

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INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING 2024年第2期17卷 37-46页

作者： Zhang, Zhenguo Zeng, Chao Xing, Zhenyu Xu, Peng Guo, Quanfeng Shi, Ruimeng Wang, Yunze Xinjiang Agr Univ Coll Mech & Elect Engn 311 Nongda East Rd Urumqi 830052 Peoples R China Xinjiang Agr Univ Key Lab Xinjiang Intelligent Agr Equipment Urumqi 830052 Peoples R China

Understanding the biomechanical properties of safflowers is essential for appropriately designing harvesting machinery and optimizing the harvesting process. Safflower is a flexible crop that lacks a basis for relevant simulation parameters, which causes difficulties in designing harvesting machinery. In this study, a calibration method for safflowers was proposed. First, a discrete element model was established by measuring the intrinsic parameters of a safflower, such as its geometric parameters, density, Poisson's ratio, and modulus of elasticity. Second, the contact and bonding parameters were calibrated using a combination of physical and simulation tests. In the contact parameter tests, the Hertz-Mindlin (no-slip) model was implemented for the stacking angle tests conducted regarding the safflower filament. A regular two-level factorial design was used to determine the important factors and perform the steepest climb test. Moreover, the Box-Behnken design was adopted to obtain the optimal contact parameters. In the bonding parameter tests, the Hertz-Mindlin model with bonding contact was applied for the safflower shear simulation tests; moreover, the optimum bonding parameters were obtained through the central composite design test. The results demonstrated that the relative errors between the simulated and measured stacking angles and maximum shear were 3.19% and 5.29%, respectively. As a result, the safflower simulation parameters were accurately calibrated, providing a reference for appropriately setting the simulation parameters and designing key mechanical components.

关键词： safflower DEM parameter calibration shear test biomechanical properties simulation

Optimization design of the hydro-pneumatic suspension system for high clearance self-propelled sprayer using improved MOPSO algorithm

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INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING 2024年第2期17卷 109-122页

作者： Yang, Fan Du, Yuefeng Wen, Changkai Li, Zhen Mao, Enrong Zhu, Zhongxiang China Agr Univ Coll Engn Beijing 100083 Peoples R China China Agr Univ Beijing Key Lab Optimized Design Modern Agr Equipm Beijing 100083 Peoples R China

Large high clearance self-propelled sprayers were widely used in field plant protection due to their high-efficiency operation capabilities. Influenced by the characteristics of field operations such as high power, heavy weight, high ground clearance, and fast operation speed, the comprehensive requirements for the ride comfort, handling stability and road friendliness of the sprayer were increasingly strong. At the present stage, the chassis structure of the high clearance selfpropelled sprayer that attaches great importance to the improvement of comprehensive performance still has the problems of severe bumps, weak handling performance and serious road damage in complex field environments. Therefore, this paper proposes an optimization design method for hydro-pneumatic suspension system of a high clearance self-propelled sprayer based on the improved MOPSO (Multi-Objective Particle Swarm Optimization) algorithm, covering the entire process of configuration design, parameter intelligent optimization, and system verification of the high clearance self-propelled sprayer chassis. Specifically, chassis structure of the hydro-pneumatic suspension suitable for the high clearance self-propelled sprayer was designed, and a design method combining the improved MOPSO algorithm based on time-varying fusion strategy and adaptive update with the parameter optimization of hydro-pneumatic suspension based on this algorithm was proposed, and finally the software simulation and bench performance verification were carried out. The results show that the optimized hydropneumatic suspension has excellent vibration reduction effect, and the body acceleration, suspension dynamic deflection and tire deflection were increased by 16.5%, 9.9% and 0.9% respectively, compared with those before optimization. The comprehensive performance of the hydro-pneumatic suspension designed in this study is better than that of the traditional suspension.

关键词： high clearance self-propelled sprayer vibration reduction hydro-pneumatic suspension MOPSO multi-objective optimization GENETIC ALGORITHM

Distributions of Electromagnetic Fields and Forced Flow and Their Relevance to the Grain Refinement in Al–Si Alloy Under the Application of Pulsed Magneto-Oscillation

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Acta Metallurgica Sinica(English Letters) 2022年第2期35卷 254-274页

作者： Yan-Yi Xu Jing Zhao Chun-Yang Ye Yan-Ping Shen Xin-Cheng Miao Yun-Hu Zhang Qi-Jie Zhai Center for Advanced Solidification Technology Shanghai UniversityShanghai 200072China key lab of intelligent equipment digital design and process simulation Tangshan UniversityTangshan 063000Hebei ProvinceChina School of Materials Science and Engineering University of Science and Technology LiaoningAnshan 114051China

Distributions of electromagnetic fields and induced forced flow inside a metal melt are crucial to understand the grain refinement of the metal driven by pulsed magneto-oscillation(PMO).In the present study,PMO-induced electromagnetic fields and forced flow in Ga-20 wt%In-12 wt%Sn liquid metal have been systematically investigated by performing numerical simulations and corresponding experimental *** numerical simulations have been confirmed by magnetic and melt flow *** to the simulated distribution of electromagnetic fields under the application of PMO,the strongest magnetic field,electric eddy current and Lorentz force with inward radial direction inside the melt are concentrated adjacent the sidewall of cylindrical melt at the cross section of middle height of *** a result,a global forced flow throughout the whole cylindrical column filled with Ga-20 wt%In-12 wt%Snmelt is initiated with a flow structure of two pair of symmetric *** PMO-induced electromagnetic fields and forced flow in Al-7 wt%Si melt have been numerically *** contribution of electromagnetic fields and forced flow to the grain refinement of Al-7 wt%Sialloy under the application of PMO is *** indicates that the forced flow may play a key role in the grain size reduction.

关键词： Pulsed magneto-oscillation(PMO) Electromagnetic field Forced flow Solidification Grain refinement

Analysis and Optimization of Flow-Guided Structure Based on Fluid-Structure Interaction

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Fluid Dynamics & Materials processing 2023年第6期19卷 1573-1584页

作者： Yue Cui Liyuan Wang Jixing Ru Jian Wu key laboratory of intelligent equipment digital design and process simulation Hebei ProvinceTangshan UniversityTangshan063000China Department of intelligent Manufacturing Tangshan Vocational College of Science and TechnologyTangshan063001China Beijing Materials Handling Research Instituted Co. Ltd.Beijing100010China

Gases containing sulfur oxides can cause corrosion and failure of bellows used as furnace blowers in high-temperature *** order to mitigate this issue,the behavior of an effective blast furnace blower has been examined in ***,the Sereda corrosion model has been introduced to simulate the corrosion rate of the related bellows taking into account the effects of temperature and SO_(2) gas;such results have been compared with effective measurements;then,the average gas velocity in the pipeline and the von Mises stress distribution of the inner draft tube have been analyzed using a Fluid-Structure Interaction ***,the semi-closed internal corrosion environment caused by a 5 mm radial gap between the inner draft tube and the bellows has been *** gas flow rate in the residential space has been found to be low(0.5 ms–this value leads to a stable semi-closed internal corrosion environment for exhaust gas exchange);water phase in the exhaust gas is prone to accelerate the corrosion *** this basis,a bellows with an optimized inner draft tube has proposed,which includes corrosion-resistant honeycomb buffer rings.

关键词： Bellows optimized inner draft tube FSI(Fluid-structure interaction) corrosion rate

Effect of die structure parameters on deformation behavior of bent tube in free bending process

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Journal of Iron and Steel Research(International) 2023年第3期30卷 487-503页

作者： Wei Wang Cheng Cheng Li Wan Jie Tao Xun-zhong Guo Chun-mei Liu College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100JiangsuChina State key laboratory of digital Manufacturing equipment and Technology Huazhong University of Science and TechnologyWuhan 430074HubeiChina Capital Aerospace Machinery Corporation Beijing 100076China

The bending section of tube between the bending die and the guider is in a less constrained state during the free bending *** free bending dies have the important impact on the plastic deformation behavior and the forming quality of *** study the evolution law of the deformation behavior of tube with the die structure parameters and optimize the free bending die parameters,the free bending experiments and the corresponding numerical simulations were carried *** design principle of free bending die was *** free bending experiment was conducted to verify the reliability of the numerical simulation *** on the numerical simulation results,the influence of the distance between the center point of bending die and the front end of guider on the forming quality of bent tube is more obvious than that of the fillet of ***,the fillet of bending die hardly affects the stress and strain distribution and the evolution of the wall ***,the free bending experiments with the newly determined free bending dies were *** ultimate bending radius of bent tube is reduced and the forming quality is improved.

关键词： Free bending Die structure parameter Forming quality Numerical simulation Tube

Virtual assembly framework for performance analysis of large optics

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Virtual Reality & intelligent Hardware 2020年第1期2卷 28-42页

作者： Jinli ZHANG Hui WANG Bowu LIU Dongya CHU Xu XU Guoqing PEI Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering State Key Laboratory of TribologyBeijing Key Lab of Precision/Ultra-Precision Manufacturing Equipment and ControlTsinghua UniversityBeijing 100084China

Background A longstanding technological challenge exists regarding the precise assembly design and performance optimization of large optics in high power laser facilities,comprising a combination of many complex problems involving mechanical,material,and laser beam *** In this study,an augmented virtual assembly framework based on a multiphysics analysis and digital simulation is presented for the assembly optimization of large *** framework focuses on the fundamental impact of the structural and assembly parameters of a product on its optical performance;three-dimensional simulation technologies improve the accuracy and measurability of the *** iterative computation algorithms have been developed to optimize the assembly plan of large optics,which are significantly affected by a series of constraints including dynamic loads and nonlinear ambient *** Finally,using a 410-mm-aperture frequency converter as the study case,we present a detailed illustration and discussion to validate the performance of the proposed system in large optics assembly and installation engineering.

关键词： Virtual assembly Multiphysics simulation Large optics

Numerical techniques for coupling hydrodynamic problems in ship and ocean engineering

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Journal of Hydrodynamics 2020年第2期32卷 212-233页

作者： Xiao-song Zhang Jian-hua Wang De-cheng Wan Computational Marine Hydrodynamics lab(CMHL) State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Most hydrodynamic problems in ship and ocean engineering are complex and highly *** the trend of intelligent and digital design for ships and ocean engineering structures,comprehensive performance evaluation and optimization are of vital importance during *** this process,various coupling effects need to be accurately *** the significant progress of computational fluid dynamics(CFD),many advanced numerical models were proposed to simulate the complex coupling hydrodynamic problems in ship and ocean engineering *** this paper,five key coupling hydrodynamic problems are introduced,which are hull-propeller-rudder coupling,wave-floating structure coupling,aerodynamic-hydrodynamic coupling,fluid structure coupling and fluid-noise coupling,*** paper focuses on the numerical simulation techniques corresponding to each coupling problem,including the theories and the *** directions and conclusions are provided finally.

关键词： Coupling hydrodynamic problems numerical techniques ship and ocean engineering