Research Of Roll Stability Of Wheeled Tractor Based On Virtual Prototyping Technology

In recent years,the agricultural mechanization speeded up the process of China's agricultural development.According to statistics,the number of large and medium-sized tractors remained high under the stimulating subsidy policy of agricultural machinery purchase in last few years.When watching tractor ownership increasing year by year,the wheeled tractor rollover stability problems continue to appear.Rollover stability is one of the important indexes to evaluate the safety performance of the wheeled tractor."The promotion of agricultural machinery appraisal outline" was revised to add the wheeled tractor roll stability angle requirements in the 2009,which require the maximum stable angle greater than 35 degrees."Maximum stability inclination angle" of wheeled tractor whose power below 110kW must be carried out as a category I indicators identified in the promotion of the assessment.At present,many domestic and foreign scholars carried out extensive research on the vehicle's roll stability.Virtual prototype technology with the development of computer technology has been widely applied.But a special application of virtual prototype technology to research wheeled tractor roll stability was rarely reported.According to domestic and international standards and regulations regarding wheeled tractor rollover stability and combined with the structural characteristics of wheeled tractor itself,a series of analysis and simulation about wheeled tractor roll stability were taken in this paper.A 30 horsepower medium-sized wheeled tractor was selected for the study.The research highlights are:first,the physical prototype was abstracted to establish the whole vehicle static roll stability model and dynamic roll stability model.Through the study of the stress analysis of the whole model to solve out the influential factors on wheeled tractor roll stability.This will help to targeted catch the focus on physical prototype modeling and simulation lately.Second,according to the 2D drawings and related technical parameters,some main assemblies,such as the engine,transmission,steering system,braking system,walking system,hydraulic suspension device,a traction device and power output apparatus are established by 3D modeling software UG,then complete virtual mock-wheeled tractor was assembled in accordance with the technical conditions and specified accuracy requirements.Third,tractor static rollover stability test,the front wheel tread empty side tumbling stability test and dynamic multi-working roll stability test were simulated in ADAMS software.The tests were used to verify the effect of the sensitive factors got from the theoretical analysis for wheeled tractor roll stability.Fourth,the simulation tests in ADAMS were verified by the corresponding real vehicle tests.By comparing the test data and simulation results,the accuracy of the whole vehicle model was verified.And it also proved the feasibility of virtual prototyping technology in the study of the wheeled tractor roll stability.Compared simulation results with test results show that virtual prototyping technology can greatly improve the qualified rate of physical prototypes.The simulation can replace the real vehicle test in a certain extent,greatly shorten the development cycle and reduce the design cost.