Rice yield is crucial for global food security, and mechanized rice transplanting plays a vital role in boosting production. The complexity of the soil environment is increasing as the global rice cultivation area is shrinking year by year. Mechanized rice seedling transplanting heavily relies on the paddy field chassis. However, challenging paddy fields can significantly affect chassis performance, such as factors like different soil types, mud depth, and the roughness of hard strata, which ultimately impact the quality and yield of rice planting. The walking wheel of paddy field chassis is subjected to complex mechanical interactions with challenging paddy fields that are difficult to quantify and control. Quantifying these interactions enables precise optimization of chassis mechanical dynamics, thereby improving chassis performance in paddy field operations. However, existing research has not achieved precise, multi-dimensional, and dynamic measurements of the mechanical data, and lacks analytical methods for optimizing chassis performance. To address this, this study developed a sensor system for real-time, dynamic, and multi-dimensional measurement of six-axis forces on the walking wheel. Using this system, a load spectrum model for three typical operating conditions of the chassis was constructed, enabling fatigue life analysis and structural optimization. Fatigue life simulations validated the system's reliability and provided a systematic method for structure optimization. Calibration and experimental results demonstrated measurement accuracy (RMSE < 0.2 % of full scale) and excellent waterproof performance. This work can provide technical support for studying paddy chassis mechanics and contributes to the optimization and advancement of paddy chassis and similar agricultural machinery.

This study aims to analyze the fatigue life of a PTO (power take-off) gearbox used in a paddy field power chassis. The analysis considers factors such as stress concentration, dimensions, surface quality, and load characteristics affecting fatigue life. A finite element simulation was conducted using the Ansys 2022 software to identify the critical point of the PTO shell. The modified nominal stress fatigue analysis method, incorporating a stress adjustment coefficient, was employed to derive the modified S-N curve. Combined with the measured load data of the PTO bench operation, the load data and the 3D model of the PTO shell were imported into the fatigue analysis software n-code to analyze the fatigue life of the PTO gearbox of a paddy field power chassis and compare it with the prediction results from the traditional stress field strength method. The findings indicate that the optimized stress adjustment coefficient method predicts a fatigue life (31,699 h) closer to the actual operational life (20,000 h) compared to the traditional method (39,151 h). This research contributes to the advancement of the analytical techniques for predicting fatigue life in critical components of agricultural machinery.

This investigation considered the effects of both internal and external excitation vibrations on the efficacy of the seed dispenser in a rice precision hole seeder. Through comprehensive field tests, we analyzed vibrational characteristics during direct seeder operations and established a vibration seeding test bed for systematic examination of these effects. Time-domain analysis of the vibration data revealed a predominantly vertical vibration direction, with notably higher levels in sandy loam soil compared to clay loam. A correlation was observed between increased engine size and rotary ploughing speeds, as well as forward speed and elevated vibration amplitudes. Frequency domain analysis pinpointed the primary vibration frequency of the machinery within the 0–170 Hz range, remaining consistent across different operating conditions. Crucially, bench test results indicated that seeding accuracy and dispersion were significantly influenced by vibration frequencies, particularly within the 70–130 Hz range, where a decrease in accuracy and increase in dispersion were noted. A regression model suggested a complex, non-linear relationship between seeding performance and vibration frequency. These insights highlight the necessity for a robust mechanism to effectively address these vibrational impacts. This study paves the way for enhancing the operational efficiency of the rice precision hole seeder, aiming to achieve the design goals of minimized vibrations in the paddy power chassis.

The parameters of the discrete element simulation model for rice field soils serve as valuable data references for investigating the dynamic characteristics of the walking wheel of high-speed precision seeding machinery in paddy fields. The research specifically targets clay loam soil from a paddy field in South China. Calibration of essential soil parameters was achieved using EDEM_2022 software (and subsequent versions) discrete element simulation software, employing the Edinburgh Elasto-Plastic Adhesion (EEPA) nonlinear elastic-plastic contact model. The tillage layer and plough sub-base layer underwent calibration through slump and uniaxial compression tests, respectively. Influential contact parameters affecting slump and axial pressure were identified through a Plackett–Burman test. The optimal contact parameter combinations for the discrete element model of the tillage layer and plough sub-base layer were determined via a quadratic rotational orthogonal test. The accuracy of the discrete element simulation model’s parameters for paddy field soils was further validated through a comparative analysis of the simulation test’s cone penetration and the field soil trench test. Results indicate that the Coefficient of Restitution, surface energy, Contact Plasticity Ratio, and Tensile Exp significantly influence slump (p < 0.05). Additionally, the Coefficient of Restitution, Contact Plasticity Ratio, coefficient of rolling friction, and Tangential Stiff Multiplier significantly impact axial pressure (p < 0.05). Optimal contact parameters for the plough layer were achieved with a particle recovery coefficient of 0.49, a surface energy of 18.52 J/m2, a plastic deformation ratio of 0.45, and a tensile strength of 3.74. For the plough subsoil layer, optimal contact parameters were a particle recovery coefficient of 0.47, a coefficient of interparticle kinetic friction of 0.32, a plastic deformation ratio of 0.49, and a tangential stiffness factor of 0.31. Results from the cone penetration test reveal no significant disparity in compactness between the actual experiment and the simulation test. The calibrated discrete element model’s contact parameters have been verified as accurate and reliable. The findings of this study offer valuable data references for understanding the dynamic characteristics of the walking wheel of the entire machinery in high-speed precision seeding in paddy fields.

To elucidate the vibrational characteristics of power chassis in paddy fields, we examined the Yanmar VPG6G rice transplanter across diverse terrains, including paddy fields, dry land, and concrete roads. Vibrational acceleration measurements, taken in longitudinal, transverse, and vertical orientations at key chassis locations, revealed noteworthy findings. The Mizuta power chassis exhibited its lowest root-mean-square (RMS) vibrational acceleration on concrete, while the highest was observed on paddy fields. The acceleration power spectra predominantly peaked between 1~14 Hz, with peak values amplifying as speed increased. Additionally, pendant orientation frequencies exceeded those of longitudinal and lateral directions. Both front and rear wheels mirrored the vibrational accelerations of the rear axle, but dynamic load coefficients for the front wheels consistently surpassed the rear, particularly at elevated speeds. This research not only enhances our understanding of terrain-induced vibrations and the intricate dynamics between terrain and tires but also lays the groundwork for designing optimized vibration-damping solutions tailored to prevalent road conditions.

Power Take Off （PTO） is a key component in power transmission route of rice transplanter.In order to explore the structure and working principle of PTO,reverse modeling of PTO chassis of Yanmar VP-6D transplanter based on 3D scanner and Geomagic Design X was carried out.The methods of acquisition and processing of model point cloud data,model establishment and error analysis,format conversion and model assembly were elaborated.The modeling error detection of the reverse model is also carried out.The test results show that the average modeling deviation of upper and lower shells is 1.056 5 mm and 1.032 5 mm respectively,which provides a reference for PTO follow-up study and optimization design.

从工程教育专业认证的目的和要求出发,分析了专业认证与课程思政的关系,将课程思政融入工程训练中是工程教育专业认证中一项重要指标要求和我国高等本科工程教育的育人要素、责任.根据当前工程训练课程体系存在的问题,提出了结合专业认证要求挖掘提炼工程训练课程思政元素的切入点和方法,在工程训练融入课程思政的设计原则、重视师资队伍的思政建设和课程内容与思政要素相融合等方面进行了重点研究,有利于促进工程训练课程为工程教育专业认证的服务,进一步提高工程技术人才的培养质量,完善高等工程教育质量监控及保障体系.

从通识教育的特点和要求出发,分析了《工程技能通识训练》现有课程体系的结构和实训内容,提出了以培养非工科专业学生具有工程意识和工程创新思维为目标,进行了课程体系的优化,建立了科普化的工程技能知识内容.实践表明,新的课程体系有利于提高实践教学的质量,工程技能通识训练的普及对非工科专业学生在进行课外创新活动以及对自身专业学习等方面具有重要的作用,为学生长远的发展奠定了基础.

本文分析了目前高等院校《金工实习》课程的实践教学现状和特点,提出了在金工实践教学中运用虚拟仿真技术的方法,解决当前高等院校在扩招背景下因学生人数大幅增加而实习场地和设备数量不足的问题。

本文以一种农用车辆液力缓速器的外壳作为研究对象,利用有限元技术对其散热性能作了数值模拟,掌握了其基本散热的规律,提出了散热筋板在液力缓速器壳体设计时应该根据温度云图来分布加入并根据其散热规律对其结构的改进提出了设计的依据。

分析现代农业的发展对农业工程技术的依赖度,阐述农业工程实验教学中心的基本特征与特点及人才培养规格,提出高校农业工程实验教学中心应以培养应用型人才为目标,以教学功能为核心,以设计性、综合性工程实验为主要手段,以本科教学为主,兼顾硕士、博士培养任务,建立多层次、多模式的农业工程实验教学内容.

为了实现蒴果壳与蓖麻籽成功剥离,载荷的大小以及载荷来自的方位相当重要.在蓖麻蒴果壳的物理特性测定分析基础上,运用接触力学对蓖麻蒴果脐部与顶部和腰部受到压载荷时,进行力学特性的试验分析与研究.结果显示蒴果在脐部与顶部受到压载荷作用时,果壳破裂的位置在蒴果顶部中缝处,中果皮内面产生裂纹而使蓖麻籽在果壳中脱出;蒴果在腰部受到压载荷作用时,果壳破裂的位置出现在蒴果中果皮中缝的两端,蒴果四周角靠近直线处也有裂纹而使蓖麻籽在果壳中脱出,蓖麻蒴果脐部与顶部受力大于腰部受力.

It analyses the factors of affecting the project cost controlling(especial in the phase of construction design),and discusses the affection of the phase of design to project cost controlling from the practitioner lack of economical consciousness and conception,the lacking of benefited market adjust and control,and the governor and decision maker lacks of the regard to the phase of design,to get the effect of explaining that the phase of design and decision should be paid more attention.

Aiming at different results of strategic decision given by product developers in multi-functioned team while conducting product planning,the coordinative treatment was carried out by the adoption of evidence theory.Taking the engineering technological index set specified by product developers as the discriminative frame of evidence theory and according to the affirmative degree of elements of discriminative frame to ascertain the distribution of basic believability of evidence.Adopting the method of weighted adjustment of evidence to lower the conflicts among evidences.Composition on the being adjusted evidences was carried out to obtain the result of coordinative treatment thus makes the product planning be able to reflect the identical views of all the product developers of the multi-functioned team.