Payam Farhadi; Abdollah Golmohammadi; Ahmad Sharifi-Malvajerdi; Gholamhossein Shahgholi
Abstract
In this study, a single tire tester was used to study the effects of vertical load, inflation pressure and moisture content on tire rolling resistance in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tire was employed and the soil texture was a clay loam. The experimental design was a completely ...
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In this study, a single tire tester was used to study the effects of vertical load, inflation pressure and moisture content on tire rolling resistance in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tire was employed and the soil texture was a clay loam. The experimental design was a completely randomized with factorial layout at three replications. A multivariate regression model was obtained with the correlation coefficient of R2=0.85 to predict the tire rolling resistance based on vertical load, inflation pressure, and moisture content. A multilayer feed-forward ANN (artificial neural network) with standard BP (back propagation) algorithm and LM (Levenberg-Marquardt) training function by using of two hidden layer in the network architecture was employed. RMSE (root mean squared error) and R2 was used as modeling performance criteria. Tire inflation pressure was identified as the controller parameter of tire rolling resistance at low moisture content and also moisture content was the most effective parameter on changing of rolling resistance in regression model. Also the obtained R2=0.977 from ANN model showed that ANN data were more close to actual data than the regression model.
Payam Farhadi; Abdollah Golmohammadi; Ahmad Sharifi-Malvajerdi; Gholamhossein Shahgholi
Abstract
One of the most important issues in agricultural machinery section is tyre - soil interactions. In this study, a single wheel tester was used to follow experiments in controlled conditions in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tyre was operated at three vertical loads of 6, 9 and 12 ...
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One of the most important issues in agricultural machinery section is tyre - soil interactions. In this study, a single wheel tester was used to follow experiments in controlled conditions in a soil bin. A Goodyear 12.4-28, 6 ply tractor drive tyre was operated at three vertical loads of 6, 9 and 12 kN, three inflation pressures of 80, 120 and 160 kPa and three moisture content of soil: 11.20, 14.86 and 18.68 % d.b to investigate the effect of the variables on these parameters: contact area, contact pressure, compaction, and soil apparent electrical conductivity. It was found that medium contact pressure had a direct relation with vertical load, inflation pressure and moisture content. A regression model with R-square of 0.946 was achieved to predict contact pressure. Soil electrical conductivity changes was predicted with acceptable determination coefficient of 0.850 by using of vertical load, inflation pressure and moisture content. Determination coefficient magnitude for models to predict resistance to soil penetration (cone index) using soil apparent electrical conductivity decreased when moisture content was increased. The vertical load and inflation pressure were found two factors controlling the soil apparent electrical conductivity changes in low and high moisture content, respectively. Error percentage in using soil apparent electrical conductivity parameter to estimate the penetration resistance increased with increasing moisture content.
