Validation of an electro-hydraulic press for dynamic measurement of elastic deformations in agricultural tires

Abstract

Tests with agricultural tires and wheelsets allow for mitigating the machinery traffic limitations to crop productivity, as it shows the tire-surface interaction under different suitability conditions, optimizing farming processes with the use of technology. Thus, this paper aims to develop an electro-hydraulic press for dynamically measuring elastic deformations occurring in agricultural tires. The experiment used a completely randomized design, evaluating two pneumatic wheelsets, bias-ply and radial, and six vertical loads, 4.9033, 9.8066, 14.71, 19.6133, 24.5166, and 29.4199 kN, on the tire, totalizing 12 treatments with five repetitions. The analyzed parameters are contact area, horizontal and vertical deflection. The collected data underwent an analysis of variance F-test and a polynomial regression analysis. The results showed continuous replicability of the data obtained with the electro-hydraulic press. That demonstrates the efficiency of the developed device for evaluating agricultural tires in a controlled environment. The bias-ply tire presented a smaller contact area than the radial with the increase of incident loads, and the 14.71 kN load achieved a higher amplitude, generating a difference of 40 %. The maximum load resulted in 27 % more horizontal deflections for the radial tire. However, the vertical deflection values were 8 % higher with the bias-ply tires.