Junming Hou

To address fruit and branch damage in mechanized sea buckthorn harvesting, this study investigates the dynamic response and damage mechanisms using the Finite Element Method (FEM) and vibration experiments. Vibration parameters were analyzed via Continuous Wavelet Transform (CWT). Key mechanical properties of branches were determined, and a fruit detachment acceleration model, along with damage indices, was established. Results indicated a fruit rupture strength of 1.577 MPa. The main contribution lies in integrating multiple approaches to elucidate vibration‐induced damage mechanisms and quantify critical harvesting parameters. The use of optimized vibration parameters, with a frequency of 16.3 Hz and an acceleration of 2.5 g ( g = 9.80 m/s ² ), was shown to improve the fruit harvest rate while minimizing damage. This study offers essential technical insights for designing efficient sea buckthorn vibration harvesters.

The mechanical properties of corn stalks play a crucial role in the design of packing and harvesting equipment. Complete and damaged stalks were used to simulate stalk mixtures during the collection process. This study measured the mechanical characteristics of complete stalks and damaged stalks through experiments. A discrete element method (DEM) model was established which incorporated both the skin and core tissues of the samples. The compression behavior of the stalks was analyzed with the EDEM 2022 software. The results indicate that the complete stalks exhibited both a plastic and second plastic stage, while the damaged stalks fractured immediately upon reaching peak stress. The models of the complete and damaged stalks were validated through a radial compression test. An analysis of the relative errors and particle velocities enabled the quantification of experimental accuracy, ensured the reliability of the experimental data, and revealed the dynamic behavior mechanism of the materials under mechanical loading. The simulation results show that the maximum compression force is 254.11 N and 33.1 N, with a 1.5% and 12.3% relative error compared to the experiment. The particle velocity in the core part is the largest, which is 9.83 × 10⁴ mm/s and 3.51 × 10⁵ mm/s. This study can provide a theoretical reference for researching the mechanical behavior and compressive failure of stalks.

Aronia melanocarpa is valued for its high nutrient content and market potential, but it is susceptible to mechanical damage during processing, leading to economic losses. In this study, the damage mechanism caused by impact during machining was investigated through drop tests and finite element simulations. High‐speed cameras recorded the fruit rebound process, and deformation energy was used to assess damage severity. The effects of drop height, contact angle, contact material, and fruit moisture content on damage levels were analyzed. Results show that with pearl cotton as the contact material, energy loss increased from 0.842 to 2.765 mJ as the drop height rose from 200 to 1000 mm. When moisture content increased to 81%, energy loss rose from 7.564 to 9.103 mJ. A contact angle of 22.5° reduced energy losses on steel plates and corrugated cardboard by 2.485 and 1.960 mJ, respectively. FEM analysis revealed that higher drop heights led to increased stress and strain. When the contact angle was 22.5°, stress and strain reached a minimum of 0.129 MPa and 0.181, corresponding to an energy loss of 3.207 mJ. Pearl cotton provided better protection, reducing stress and strain to 0.104 MPa and 0.145, with an energy loss of 1.643 mJ. These findings deepen the understanding of mechanical damage in Aronia melanocarpa and provide key parameters for optimizing processing equipment with practical applications for reducing fruit damage.

In the field of conservation tillage, no-till seeding technology has emerged as an efficient and environmentally friendly form of agricultural production. It is increasingly recognized as a crucial avenue toward sustainable agricultural development. This study focuses on the research of no-till seeding technology, specifically analyzing the technical characteristics of no-till seeders, their principles of operation, and their application. No-till planters are designed to either minimize or eliminate soil tillage. When paired with precision seeding technology, they can significantly reduce soil erosion, promote soil and water conservation, reduce agricultural production costs, and ensure optimal growing conditions for crops. No-till seeding breakers play a critical role in resolving the stubble-breaking issue that is inherent in no-till seeding technology. The integration of no-till planters with stubble breaker knife technology can substantially improve the adaptability and operational efficiency of no-tillage operations under conservation tillage scenarios. This progress offers indispensable technical backup, which not only aims to ramp up food production levels but also contributes agro-ecological protection of the environment.

The mechanized harvesting of mulberry is important for its production. In the process of harvesting, it is considered not only the mechanical damage of mulberry fruit but also its harvesting efficiency. It is very important to improve the vibration harvesting efficiency of mulberry. In this study, modal analysis of mulberry trees and harmonic response analysis of branches were carried out to determine the harvesting frequency of the branch's vibration and other parameters. The effects of excitation frequency and vibration position on the triaxial acceleration of the mulberry branch at different positions were analyzed by vibration test. Then the triaxial acceleration of branches at different positions was analyzed. The conditions of the mulberry fruit shedding were obtained through theoretical analysis. Through the 20-order modal analysis of mulberry, it is concluded that a better vibration effect can be achieved when the vibration frequency is controlled at 4-16 Hz. According to the harmonic response analysis, the best excitation frequencies are 5-6 Hz, 10-13 Hz, and 14-16 Hz. The harmonic response analysis of fruit branches was carried out, and the stress of fruit stalks at 5 Hz, 10 Hz, and 15 Hz were analyzed. The result shows that the maximum stress is 2.9252×107 Pa, the excitation position is the first-order branch, and the excitation frequency is 15 Hz. The frequencies obtained from modal analysis and harmonious response analysis were used to conduct experiments. When the excitation frequency was 15 Hz, the triaxial accelerations aX, aY, and aZ were 2.12 g, 4.16 g, and 3.99 g, respectively, which were more conducive to the shedding of mulberry fruits.