Damage Law And Experimental On Shelling Collision Of Castor Capsule Based On Finite Element Method

Castor seed is a kind of agricultural material with high oil content.It has important application value in aerospace,medicine and other fields,and the quality of castor oil has an important relationship with the quality of shelling.Most of the traditional castor capsule shelling equipment adopts the empirical design method.The existing shelling equipment on the market generally has the disadvantages of low shelling efficiency and excessive damage rate.Therefore,an in-depth analysis of the mechanical properties and collision damage of castor capsule provides a theoretical reference for the improvement and optimization design of the shelling equipment.The specific research contents and conclusions of this paper are as follows:(1)The typical varieties(Zhe Bi 4 and Tong Bi 17)were selected for the triaxial size statistics,and the rotundness distribution characteristics were determined.The density parameters of the outer shell and the kernel were measured by the liquid discharge method.Based on the static test,The relationship between yield strength,hardness and moisture content;based on the motion law of castor collision rebound,combined with high-speed photography equipment,establishes the mathematical model of collision restitution coefficient of castor capsule,and obtains the collision restitution coefficient of castor capsule by mixed orthogonal test.The coefficient ranges from 0.2688 to 0.4264.(2)Based on the classical Hertz theory,the contact index and energy loss factor are introduced to establish the dynamic model and energy loss model of the castor capsule in collision.The variable step Runge-Kutta algorithm is used to solve the mechanical model numerically.The law of force and deformation of different contact exponents,the law of deformation and normal stress field,and the variation of diameter-thickness ratio,energy loss factor and energy loss.The results show that when the castor capsule is colliding,the contact index has a certain influence on the force deformation,and the collision kinetic energy loss is small.In addition,based on the MATLAB language platform,the COCPS 1.0 version of the software interface for calculating the elastic collision mechanics parameters of castor capsule is developed.(3)Through the Lagrangian algorithm program,the finite element analysis of the collision between the castor capsule and the shelling parts and the shelling process is carried out,and the variation law of the total deformation and equivalent stress of the shell and the kernel of the castor capsule is obtained.The ANSYS/Design Exploration optimization module performs the OSF optimal filling test design and analyzes the response surface to obtain the totaldeformation,equivalent stress cloud map and deformation force of the specified path at different speeds.Find out the law of the shelling of the castor capsule.(4)Based on the dart-type impact load test rig and high-speed photographic equipment,for the typical castror capsule varieties,the moisture,collision height and collision angle are the test factors,and the maximum impact force and normal deformation are the test indicators.A ternary quadratic general rotation combination regression test was carried out,and the standard ternary quadratic polynomial regression proxy model of maximum impact force and normal deformation was obtained by least squares method.At the same time,based on the test results,the classification of the degree of collision damage of castor capsule is determined,and combined with multi-objective optimization algorithm(NSGA-II),the optimal parameter combination satisfying the condition of shelling of castor capsule is obtained,and the test value of the maximum impact force is close to the theoretical value.