摘要
为研究轻型地面车辆松软地面通过性能,针对轻载荷条件建立车轮牵引通过性预测模型,该文采用轮上载荷为30~90 N的轻载荷条件,以轮上载荷和轮径度为试验因素,车轮沉陷、挂钩牵引力和牵引效率为试验指标,开展滑转条件下轮壤相互作用试验研究。分析了试验因素对车轮牵引通过性的影响规律,发现载荷因素对试验指标的影响最为显著,显著性检验的置信度达90%。沉陷随着轮径的减小以及轮上载荷和滑转率的增加,车轮沉陷均呈现增加趋势,平均相对增加率分别为14.3%、36.9%和77.4%。挂钩牵引力随着载荷、滑转率和轮径的增加平均提高了约263%、295%和29.71%,牵引效率最大值均值为0.23,对应的滑转率为26.86%。基于传统沉陷模型和轮壤接触应力分布线性化公式,结合车轮土槽试验结果,建立了适合滑转条件的沉陷模型,模型计算值与试验值残差低于3.6 mm,平均相对误差小于6.4%,结果表明该模型能准确预测轻载荷条件下车轮沉陷。该研究为轻型车辆研制、轻载荷条件下车轮牵引通过性评估提供了参考。
In order to study the tractive performance of lightweight vehicle on soft ground,this research aim at establishing tractive trafficability predicted model through soil bin tests under light load.This paper adopt the condition of light load with wheel load ranging from 30 to 90 N,the wheel sinkage,drawbar pull and tractive efficiency were taken as experimental indices,the wheel diameter,load and slip ratio were as experimental factors,and the regression orthogonal experiment scheme was designed.The effects of experimental factors on wheel tractive trafficability were also analyzed.Results showed that the wheel sinkage increased with the decrease of the wheel diameter or the increase of the wheel slip ratio and load,and the average relative increase rates were 14.3%,36.9% and 77.4%,respectively.Results also indicated the wheel load had the most significant influence on the experimental indices,and the confidence coefficient value was up to 90%.Through the mentioned analysis above,a linear regression equation of wheel sinkage between wheel diameter,load was obtained.Compared with the measured and predicted values of wheel sinkage,both the residual error and the relative error of the two increased with the increase of the wheel load or the decrease of the slip ratio.The maximum residual error was less than 6.5 mm,and the range of the relative error was 1.4%-17.9%.Therefore,the linear regression equation could be used for the wheel sinkage prediction.In order to study the effects of wheel load and diameter on its tractive trafficability,experiments were also carried out when wheel load was 60 N and wheel diameter was 250 mm,separately,while the slip ratio range was 5%-60%.Results showed that the average increase ratio of the wheel drawbar pull was up to 29.71% with the increase of the wheel diameter,and it increased by 2.63 and 2.95 times with the increase of the wheel load and slip ratio,respectively.The wheel load had the most effect on the traction efficiency,the slip ratio secondary,and then the wheel diameter.When the wheel load was 60 N,the average value of maximum traction efficiency was about 0.23,and the corresponding slip ratio was 26.86%.From the results and analysis above,this paper suggests that the wheel load should be greater than 60 N to ensure the wheel traction efficiency is above 0.2,and the slip ratio between 10% and 40% is reasonable for a preferable tractive trafficability.Based on the traditional sinkage model and the linearization formula of wheel-soil contact stress distribution,and combined with testing results,a new sinkage model was established,which was suitable for the wheel slip conditions.The improved model has comprehensively considered the effects of the factors on the wheel sinkage,including wheel diameter,load,drive torque,drawbar pull and slip ratio.The range of the relative error between the model calculation values and experimental values was 0.8%-11.7%,the mean values of the relative error and the maximum residual error were less than 7.2% and 4.5 mm,respectively.Therefore,the improved model can be more accurate in the prediction of wheel sinkage,compared with the linear regression equation aforementioned.It is also appropriate for the predicting of wheel tractive trafficability.The research results of this paper provide technical methods and basic data for the development of light-weight vehicles and wheel tractive trafficability assessment under the condition of light load.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第12期64-70,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(51375199)
关键词
车辆
模型
车轮
轻载荷
牵引通过性
沉陷
模拟月壤
vehicles
models
wheels
light load
tractive trafficability
sinkage
simulant regolith