Numerical Analysis Of Failure Mechanism On Soil-tool Interaction In The High-speed Shifting Tillage Operation Of Horizontally Reversible Plough

Horizontally Reversible Plough(HRP)is an important kind of High-speed mouldboard ploughs,plowshank and plowtip of HRP take the greatest responsibility for tillage.It is demonstrated in field conditions that service life of HRP is associated with plough failures on the plowshank and plowtip zones.This is basically due to high-speed soil rheology and hence a challenging issue in agricultural engineering.It has been found that the damage of the plowshank and plowtip zones is closely related to the ploughing resistance.Therefore,it is very important to study the ploughing resistance of HRP in the high-speed shifting tillage operation under various operating conditions.In this thesis,I am focused on the following aspects:1.Study on Influencing Factors of Ploughing Resistance.We have developed a kinematic analysis model of HRP and studied the dynamic characteristics of plow tillage.We measured the characteristic parameters of typical soil and developed a calculation model of soil–tool interaction.In order to reveal the main influencing factors of the ploughing resistance of HPR,it is very important to study the ploughing resistance of HRP in the high-speed shifting tillage operation under various operating conditions.2.Determination of mechanical model of plough chisel damage.We study and determine the key parameters of the mechanical model of plow cutting and ploughing damage,the change rule of the wear rate of the plow body,and further study and determine the damage mechanics analysis model of the tilting plow body chiseling plough;A numerical analysis model for plowing damage of pendulum plow body was developed to predict the change of plowing damage of plowing body in the plowshank and plowtip zones of HRP.In order to verify the correctness of the numerical analysis model,we carried out the experiment comparison.3.Numerical analysis of the damage mechanism of the plowshank zones of HRP.We study the damage of the plowshank zones of HRP under different various operating conditions and complex tillage conditions;We study the distribution and evolution of temperature,stress and strain under different various operating conditions and complex tillage conditions;We study the qualitative and quantitative relationship between the temperature,stress and strain,so as to reveal the mechanical mechanism of the damage of the plowshank zones of HRP.4.Numerical analysis of the damage mechanism of the plowtip zones of HRP.We study the damage of the plowtip zones of HRP under different various operating conditions and complex tillage conditions;We study the distribution and evolution of temperature,stress and strain under different various operating conditions and complex tillage conditions;We study the qualitative and quantitative relationship between the temperature,stress and strain,so as to reveal the mechanical mechanism of the damage of the plowtip zones of HRP.Based on the numerical method of multi-body dynamics coupled finite element analysis,this paper studies the key influencing factors of the plow resistance.For the first time,we try to use the idea of metal cutting to establish a HRP wear simulation system.We study the mechanical mechanism of the damage of HRP in the complex field and under different operating conditions.The results provide a good theoretical clue for prolonging the cultivation life and improving the cultivation performance of high-speed plow.