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In order to improve the applicability and prediction accuracy of the existing simulation test methods of vehicle tractive performance on sandy soil, the off-road tire model using the discrete element method (DEM) under each operating condition is separately established in this paper. The contact parameters of DEM model are calibrated by rubber-sand friction test and soil bin test combined with corresponding simulation test. On this basis, the tire-sand simulation model is calculated under straight and inclining driving conditions, and the variation law of drawbar pull, torque, tractive efficiency and sinkage is obtained. This paper proves the feasibility of DEM simulation in studying vehicle tractive performance, and also provides a systematic parameter calibration method for improving the accuracy of DEM simulation, which is of great significance to enrich vehicle testing methods.

The interaction between off-road tires and granular terrain has a great influence on the tractive performance of off-road vehicles. However, the finite element method or the discrete element method cannot effectively study the interaction between off-road tires and granular terrain. The three-dimensional combined finite element and discrete element method is applied to handle this problem. In this study, a calibrated finite element method–discrete element method model is established, in which the finite element model of off-road tire is validated by stiffness tests, while the discrete element model of gravel particles is validated by triaxial compression tests. The calibrated finite element method–discrete element method model can describe the structural mechanics of the off-road tire and the macroscopic mechanical properties of the gravel road. Tractive performance simulations of the off-road tire on gravel road under different slip conditions are performed with the commercial software LS-DYNA. The simulation results are basically corresponded with the soil-bin test results in terms of granular terrain deformation and tractive performance parameters versus the slip rates. Finally, the effects of tread pattern, wheel load, and tire inflation pressure on tractive performance of off-road tire on granular terrain are investigated. It indicates that the calibrated finite element method–discrete element method can be an effective tool for studying the tire–granular terrain interaction and predicting the tractive performance of off-road tire on granular terrain. [ABSTRACT FROM AUTHOR]

The research on the interaction between off-road tires and soft ground is of great significance to improve the travel performance of off-road vehicle on soft ground. The interaction between tire and soft ground can not be described by the finite element method or the discrete element method effectively. A FEM-DEM model in which the off-road tire is modeled by the finite elements and the gravel road is modeled by the discrete elements was established based on the indoor single wheel soil bin test. The proposed model can be used to accurately describe the complex mechanical properties of off-road tire and the granular features of gravel road. The tractive performance of off-road tire on gravel road at different slip rates is simulated by using the combined finite element-discrete element method in LS-DYNA. The tractive performance parameters of off-road tire, such as tire tractive force and rim sinkage, at different slip rates were obtained and investigated. The numerically simulated results are basically corresponded with the experimental results, which verifies the validity of the combined finite element and discrete element method in studying the interaction between tire and soft ground. [ABSTRACT FROM AUTHOR]

• An efficient GPU-based DEM-FEM for the interactions between tire and granular terrain is proposed. • Including a new and efficient parallel algorithm for contact search between large-scale particles. • Including a novel and efficient parallel algorithm for contact search between particles and complex tread. • The model is consistent with the experiment, and the accuracy and validity of the results are verified. • Compared with CPU-based DEM-FEM calculation, a speedup of 84.9 can be obtained. Numerical methods have become useful tools for predicting vehicle mobility performance on granular terrain. However, due to the large number of soil particles and complex contact search in tire-granular terrain simulation, time-consuming calculation has become the most critical problem restricting the application of these methods. In this study, an efficient GPU-based DEM-FEM for simulation of the interactions between an off-road tire and granular terrain is implemented to improve computational efficiency. In this method, the main body of calculation is executed on GPU and programmed into an in-house developed code CDFP. The new GPU-based computing framework consists of 14 kernels, including efficient contact calculation between large-scale particles, novel contact calculation between particles and complex tread, contact calculation between particles and boundary wall, internal force calculation of finite elements, and information update. As a result, the efficient contact search and the complex interactions between an off-road tire and granular terrain are accomplished. Based on the self-developed single-wheel test device, an accurate simulation model consistent with the experiment is established. The validity of the proposed method is verified by comparing the simulation results with the experimental results. Finally, the discussion of computational efficiency shows that the proposed GPU-based DEM-FEM can be a powerful tool to simulate the interactions between an off-road tire and granular terrain. Image, graphical abstract [ABSTRACT FROM AUTHOR]

In order to improve the applicability and prediction accuracy of the existing simulation test methods of vehicle tractive performance on sandy soil, the off-road tire model using the discrete element method (DEM) under each operating condition is separately established in this paper. The contact parameters of DEM model are calibrated by rubber-sand friction test and soil bin test combined with corresponding simulation test. On this basis, the tire-sand simulation model is calculated under straight and inclining driving conditions, and the variation law of drawbar pull, torque, tractive efficiency and sinkage is obtained. This paper proves the feasibility of DEM simulation in studying vehicle tractive performance, and also provides a systematic parameter calibration method for improving the accuracy of DEM simulation, which is of great significance to enrich vehicle testing methods.