Simulation Study On The Performance Of Tractor With Air Suspension

At present,the commonly used tractor suspension is leaf spring suspension.Its stiffness is immutable.The comfort and stability of the vehicle is poor.This had been not suited to commercial transport on the tractor stability requirements.In addition,tractor performance test should be conducted in a specific environment and climatic conditions.Long experimental period,relatively high cost and precision test instrument had a great influence on the test results.To solve this problem,this study had completed the design and verification of the tractor air suspension.As a result,the field test was replaced by simulation testing.This was extremely important to the development of the air suspension tractor.Test performance comparison of leaf spring suspension tractor with air suspension tractor showed that air suspension tractor performed better.The result of the analysis and calculation of air suspension stiffness and vibration frequency showed that the initial inflation pressure,effective bearing area and change rate,the length of the suspension and its change rate and the sprung mass was the main factors affecting performance of air suspension.This study took a domestic tractor physical prototype as target models,optimized free diaphragm air spring as the basic structure,and completed parameter design of the air suspension.Air suspension rubber material strength analysis had been completed based on finite element analysis software ANSYS.Analysis showed that the maximum stress(16.9MPa)produced in the middle of the rubber balloon which meet the strength requirements.The digital prototype model had been completed by multibody dynamics software ADAMS.The model test had been completed through the steering wheel angle step test.The effect of null rotation(±7o)on vehicle performance parameters was discovered.The effect of null rotation on test results had been reduced comparison with the actual test results.Reference to GB/T requirements,steering returnability test and steady state circular test was selected on vehicle handling stability simulation tests.In a virtual test environment,tractor test control strategy was developed,controllability and stability test and evaluation had been completed.Quantitative test results showed that the tractor with air suspension has good handling and stability.Furthermore,triangular pulse input road was established,tractor ride comfort simulation tests had been completed.Test results showed that vertical vibration frequencies was in the body's sensitive frequency range.If the frequency within a sensitive area last a long time,it would lead to driver fatigue.The test-error had been obtained compared air suspension tractor test results with the actual test results.This study provides a guiding significance method on performance simulation of air suspension tractor.