| China is a big agricultural country,but the level of agricultural mechanization is still not high enough.In recent years,with the support of relevant policies,the level of agricultural mechanization in China has gradually improved,but the design of agricultural machinery is still short.China's terrain is complex,how to adapt the walking machinery to various terrain conditions,vehicle ground dynamics research is the method to solve this problem.Computer simulation has played an irreplaceable role in the field of mechanical design,so simulation technology will often be used in the research of vehicle ground dynamics.However,at present,most of the simulation software on the market is foreign commodity software,and there are few domestic researches on this aspect.Based on the above background,the research group developed the simulation software TDEM.After more than ten years of improvement,the simulation software AgriCAE has been developed on the basis of TDEM.Although AgriCAE software has implemented a variety of mechanical simulation calculations,there are still many problems,such as: a single wheel boundary modeling method,which can only be modeled using database reading;unable to simulate elastic wheels with patterns;Uneven road surface;each calculation takes too much time to set the calculation parameters;the calculation parameter query lacks content;the performance analysis function is inaccurate,etc.In order to solve the above problems,this article first conducts demand analysis,and then makes the following improvements to AgriCAE software:The research improves the wheel boundary modeling method and adds the function of using simple primitives to establish the wheel boundary model.That is,there is no wheel boundary model in the user's database,and the wheel boundary model can also be established by a simple graphical element method.Study and design the modeling function of elastic wheel tire pattern(generation of tire pattern).A total of 7 patterns are added,of which the "herringbone" pattern is unique to AgriCAE software.By adjusting various parameters of the tire pattern,the elastic tire of the wheeled off-highway vehicle can be simulated in most cases,which is closer to the real situation,and it is convenient to study the effect of the tire pattern on the wheel motion.Research and design the modeling function of uneven pavement,and increase the generation area of irregular-shaped mesh particles.By changing the parameters of the grid,and then generating soil particles in the grid of irregular shape,various uneven road surfaces can be simulated to facilitate the study of the influence of the uneven road surface on the driving performance of the vehicle.Research and design the module of calculation parameter saving and importing function.The calculation parameters include boundary modeling parameters and discrete element calculation parameters.If multiple simulations are performed,and the parameters used in each simulation are not much different,the calculation parameters are only set and saved during the first simulation,which can be directly imported and used in subsequent simulations,which can reduce the time spent setting the calculation parameters.The research improves the calculation parameter query function and adds the content of calculation parameters that can be queried,such as CFD parameters,MBK / MBD parameters,and calculation time parameters.Design and increase the calculation parameter export function,save the calculated calculation parameters to the file in the form of a table.Research and improve the performance analysis function module.The flow analysis function is improved,and the flow statistics algorithm is improved to make the flow analysis more accurate.Improve the wheel performance analysis function,increase the analysis of wheel performance parameters on the original basis,and optimize the interface.The research and design of the performance analysis curve export function,the value of each moment in the performance analysis curve is exported to a txt file,which can facilitate performance analysis.Finally,using multiple test cases to test each functional module improved in this article.It is proved that the improved function of the three-dimensional discrete element method simulation software AgriCAE is correct,and the expected effect is achieved. |
