| In recent years,the situation of safeguarding our country’s Marine territorial legal rights has been becoming more serious,so we need to make early preparations and strengthen the study of our troops’ loading vehicle through-sand capability for increasing the army mobility on beachhead when the army will occupy and control islands.In addition,with the implement of Chinese lunar exploration project,the bad road conditions of lunar sandy soil brings a big challenge for the vehicle’s ability of walking on lunar surface.A study of the vehicles’ contact process in sand soil and wheel traction issues is the foundation and key for solving the problem of vehicle through-sand capability.Basing on wheel-sand interaction and wheel traction performance research needs,choosing Dongfeng Mengshi’ wheels and aeolian sand on beach in Guangdong as research objects,using the discrete element method,which has unique advantages on particle medium micromechanics analysis,to establishing wheel-sand and sand soil particle flow model,and carrying out the simulation analysis of the soil groove test and the wheel traction performance.Mainly research work and results as shown bellow:1.Selecting typical sea sand of the South China sea as sample,with the vehicle main effect soil making appropriate sampling,in accordance with the "regulations of soil test" and "soil test method standard" conducts a test,and determined the basic physical characteristics and mechanical properties of the sample.2.Through PFC3 D simulation the indoor triaxial test,analysising the relationship between discrete element mesoscopic parameters and macroscopic mechanical parameters,and establishing discrete linear stiffness model of the sea sand on this base.3.Based on vehicle ground mechanics semi-empirical method research results,keep the wheel grounding mean pressure and contact angle as principle,analysing and deducing wheels’ s parameter variational relationship between the diameter of equivalent and scale wide,and then through simulating bearing plate test and numerical fitting extract the sea sand’s Bekker mechanical parameters,constructing the Dongfeng Mengshi wheel scale model.4.Setting wheel’ rigid conditions,using PFC built-in language for secondary development and use the method of particle clumps to generate particles aggregation of the wheel,which have adjustable structure of the three-dimensional discrete element model.5.According to the indoor soil bin testing principle and parameter setting,establishing the test system of wheel-sand interaction simulation system.Through the simulation of the traction performance test,The influence of the parameters of the medium model,the parameters of the wheel and the structure parameters on the traction characteristics of the driving wheel are studied.The research shows that the traction performance of the driving wheel can be improved by increasing the wheel width,wheel diameter and the installation of gear teeth. |
