A Research On Ride Comfort Of Semi-Tractor From Parameter Matching And Optimization

According to the rapid development of China economy, the transportation by semi-tractor will be leading the mass logistics in China market. The comfort performance is going to be very important index to the sale of truck manufacturers.This paper is referred from ISO2631-1:1997, Mechanical vibration and shock– Evaluation of human exposure to whole-body vibration– Part 1: General requirements, analyses the parameters to impact comfort, both on the impact from single parameter alone and the parameters coupling effect. After the analyses, the comfort of some 4X2 semi-tractor has been improved through the simulations and test validations.First of all, a simplified 2D model with 6 freedom is been set up by ADAMS.Secondly, the parameters, such as dimensions, weight, stiffness, and damping, should be calibrated. To simplify the model, the big components such as engine, transmission, fuel tank, and so on, are simplified dot masses, and meet the similar weight distribution between the two axles. The stiffness and damping value are from the bench test on the suspension components.To avoid the influence from the tyre, the acceleration on the axles are collected directly to take the place the impact from road.Thirdly, after the calculations are focus on the comfort impact from single parameter alone, the sensitive analyses shows the result: the wheelbase and pin distance of the sample truck are less influence on comfort. The largest influence on comfort is from the front suspension stiffness and rear suspension stiffness, and cab suspension stiffness and chair suspension stiffness will get different trend of result.Fourthly, the analyses on the stiffness parameters coupling effect shows the result: all the better trend by single parameter alone will lead better comfort.Finally, according to the analyses result before, the improving draft is set up. After the test validation, the trend calculations and the test result is same, which proved the analyses. The comfort performance of sample truck is improved 15.3% finally.This paper is described some innovations: (1) The target of comfort targets is from the benchmark on the products from other competitors, and the evaluations are very directly and very easy to do;(2) The analyses are not only focus on the impact from single parameters alone, but also on the stiffness parameters coupling effect;(3) To avoid the influence from the tyre, the acceleration on the axles are collected directly to take the place the impact from road. So the model is simplified and the precision of calculation will be improved.The model and analyses method are explored to the new platform of semi-tractors. The comfort performance is under controlled before test validation by the simulations, and gets the level near the truck from Europe. Then, the sales of the products is boosting by the improvement of comfort performance.