Donghui Lu

The effect of tine geometry during vertical movement on soil penetration resistance using finite element analysis

New tillage and planting tools causing low soil disturbance and minimizing vegetation deterioration are desired in the conservation tillage technology development. This paper attempted to study the effect of tine geometry in its vertical movement on penetration resistance. Four kinds of tines were defined (i.e. rectangle, triangle, crescent and mososeries) based on the geometry of the cutting edge. The effects of tine geometry, thickness, and penetration depth on soil penetration resistance were investigated and side soil disturbance evaluated. Finite element method with a Drucker–Prager elasto-plastic model was introduced to simulate the material behavior of sandy loam soil taken from Hebei province in China. Each tine was considered as a discrete rigid body with a reference point at the top-midpoint of the central plane, at which the vertical force (penetration resistance) was calculated. Results indicated that the rectangle tine obtained the highest penetration resistance as compared to the others. Penetration resistances of all the tines increased with the attack surface area with a power function, nonlinear tendency with thickness and a quadratic function with penetration depth. A crescent soil deformation area existed through the penetration process. It can be concluded that the FEM can maximize the understanding of tine geometry effects on penetration resistance and soil deformation area.

Optimization of Binder Addition and Compression Load During the Pelletization of Wheat Straw Using Response Surface Methodology

Abstract. Densification is required for efficient handling and transportation biomass as feedstock for biofuel production. Binders can enhance the straw pellet strength and improve pellet performance. The present investigation is to optimize binder addition of wheat straw pelletization process by using a single pelleting unit. Response surface methodology was employed by using a four factor five level Central Composite Design with wood residue, bentonite, crude glycerol addition by mass fraction and compression force as process parameters. Pellet tensile strength, specific energy consumption and pellet density were the response variables. The higher heating value, ash content and the cost of the pellet were also considered when optimized binders. The results showed that the developed model fitted the data and was adequate for binder analysis. Wheat straw pelleted with 30% wood residue, 0.80% bentonite and 3.42% crude glycerol addition and 4000 N compressive force was identified as the optimal process parameter with low ash content (6.13%) and high heating value (18.64 MJ t -1 ). Pellet tensile strength, specific energy consumption and pellet density values were 1.14 MPa, 32.6 MJ t -1 and 1094 kg m -3 , respectively. Confirmation tests indicated high accuracy of the model.

Research on the Demand of Alfalfa Harvest Machine in China’s Northern and North-west Regions

Abstract. The harvest machinery is the foundation of mechanized production for alfalfa, the study on the demand of alfalfa harvest machinery can improve the comprehension level of the harvest machinery market situation and the development tendency in China’s northern and north-west regions, and it can lead the scientific research institution or company to develop and improve the harvest machinery. The questionnaire was designed to analyze the consumer behavior in the process of selecting or purchasing the alfalfa harvest machine. Through questionnaire investigation and factor analysis, this paper reduced the influencing factor indexes to accessible factor by using SPSS and built a multivariate linear equation model. Based on the qualitative analysis and quantitative analysis, the advice on the development of alfalfa harvest machine was proposed.

Development of an optimized forage harvest machinery system selection factors analysis model using analytic network process and DEMATEL

Machinery harvest system is one of the most important key links in the whole forage production processing. A model for selecting machines and optimizing machinery matching for harvest system was developed by considering the important factors of environment, social, economic, policy and so on. The factor analysis, evaluation and optimization process was accomplished by using Delphi method, analytic network process (ANP) and DEMATEL. The model was evaluated for three regions with crop of alfalfa. The results showed that this model is possible for different users to select, evaluate and optimized their machinery harvest system.