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The purpose of this study is to determine the effect of tire operating conditions, such as the tire inflation pressure, speed, and load on the change of the first mode of vibration. A wide base FEA tire (445/50R22.5) is virtually tested on a 2.5m diameter circular drum with a 10mm cleat using PAM-Crash code. The varying parameters are altered separately and are as follows: inflation pressure, varying from 50 psi to 165 psi, rotational speed, changing from 20 km/h to 100 km/h, and the applied load will fluctuate from 1,500 lbs. to 9000 lbs. Through a comparison of previous literature, the PAM-Crash FFT algorithmic results have been validated.

Modern Finite Element Analysis (FEA) techniques allow for accurate simulation of various non-linear systems. However they are limited in their simulation of particulate matter. This research uses smooth particle hydrodynamics (SPH) in addition to FEA techniques to model the properties of soils, which allows for particle-level replication of soils. Selected soils are simulated in a virtual environment and validated using the pressure-sinkage and shear tests. A truck tire model is created based on standard heavy vehicle tires and validated using static deflection, contact footprint, and dynamic first mode of vibration tests. The validated tires and soils are used to create a virtual terrain and the tire is placed on the soil, loaded, and run over the soil at various speeds. The results of these simulations show that the SPH modeling technique offers higher accuracy than comparable FEA models for soft soils at a higher computational cost.

Off-road vehicle performance of a multi-wheeled 8×8 combat vehicle is strongly affected by the tire-terrain interaction characteristics. Soft soil reduces traction and modifies vehicle handling; therefore tire dynamics play a strong role in off-road mobility evaluation. In this paper three-dimensional, non-linear Finite Element Analysis (FEA) off-road tire models are developed using PAM-CRASH and the general trends of vertical load-deflection, cornering characteristics and aligning moment on rigid terrains are predicted and compared with published, measured data of a similar tire for validation purposes. The FEA off-road tire models are used to investigate the multi-pass behavior of the wheels running and steering on soft terrain. The steering characteristics of the multi-wheels are also predicted for the purpose of the development of tire-soft soil empirical equations for future research work.

This paper investigates the impact of tread design on the tire-terrain interaction of two similar-sized truck tires with distinctly different tread designs running over various terrains and operating conditions using advanced computation techniques. The two truck tires used in the research are off-road tires sized 315/80R22.5 wide which were designed through Finite Element Analysis (FEA). The truck tire models were validated in static and dynamic domains using several simulation tests and measured data. The terrain includes a flooded surface and a snowed surface which were modelled using Smoothed-Particle Hydrodynamics (SPH) technique and calibrated using pressure-sinkage and direct shear tests. Both truck tire models were subjected to rolling resistance and cornering tests over the various flooded surface and snowed surface terrain conditions on the PAM-CRASH software.

This paper presents the modelling, calibration and sensitivity analysis of LETE sand soil using Visual Environment’s Pam Crash. LETE sand is modelled and converted from Finite Element Analysis mesh (FEA) to Smooth-particle hydrodynamics (SPH). The sand is then calibrated using terramechanics published data by simulating a pressure sinkage test and shear box test using the SPH LETE sand particles. The material properties such as tangent modulus, yield strength and bulk modulus are configured so the simulation’s results match those of theoretical values. Sensitivity analysis of the calibrated LETE sand material is then investigated. The sensitivity analysis includes mesh size, plate geometry, smoothing length, max smoothing length, artificial viscosity and contact thickness. The effect of these parameters on the sand behavior is analyzed.

The purpose of this research paper is to outline the procedure behind the parameter population of a wide-base rigid ring model. A rigid ring model is a mathematical representation of a highly non-linear FEA tire model that incorporates the characteristics and behaviour of a known physical tire. The rigid ring model parameters are determined using carefully designed virtual scenarios which will isolate for the parameter in question. Once all of the parameters have been calculated, for in-plane as well as out-of-plane parameters, a full rigid ring model can be populated. This model can also be modified to accommodate for a tire model simulated running over soft soils if necessary. For the purpose of this research however, the soft soil parameters were not determined. Once the rigid ring model is complete, the parameters can be used in a highly simplified virtual model to replicate the known behaviour of the tire but reduce the overall complexity of the full vehicle model.

A performance investigation of Front Underride Protection Devices (FUPDs) with varying collision interface is presented by monitoring occupant compartment intrusion of Toyota Yaris and Ford Taurus FEA models in LS-DYNA. A newly proposed simplified dual-spring system is developed and validated for this investigation, offering improvements over previously employed fixed-rigid simplified test rigs. The results of three tested collision interface profiles were used to guide the development of two new underride protection devices. In addition, these devices were set to comply with Volvo VNL packaging limitations. Topology optimization is used to aid engineering intuition in establishing appropriate load support paths, while multi-objective optimization subject to simultaneous quasi-static loading ensures minimal mass and deformation of the FUPDs.

The rigid-ring tire model is a simplified tire model that describes a tire's behaviour under known conditions through various in-plane and out-of-plane parameters. The complex structure of the tire model is simplified into a spring-mass-damper system and can have its behaviour parameterized using principles of mechanical vibrations. By designing non-linear simulations of the tire model in specific situations, these parameters can be determined. They include, but are not limited to, the cornering stiffness, vertical damping constants, self-aligning torque stiffness and relaxation length. In addition, off-road parameters can be determined using similar methods to parameterize the tire model's behaviour in soft soils. By using Finite Element Analysis (FEA) modeling methods, validated soil models are introduced to the simulations to find additional soft soil parameters.

This work investigates a multi-objective optimization approach for minimizing design parameters for Front Underride Protection Devices (FUPDs). FUPDs are a structural element for heavy vehicles to improve crashworthiness and prevent underride in head-on collision with another vehicle. The developed dsFUPD F9 design for a Volvo VNL was subjected to modified ECE R93 testing with results utilized in the optimization process. The optimization function utilized varying member thickness to minimize deformation and system mass. Enhancements to the function were investigated by introducing variable materials and objectifying material cost. Alternative approaches for optimization was also needed to be explored. Metamodel-based and Direct simulation optimization strategies were compared to observe there performance and optimal designs. NSGA-II, SPEA-II Genetic Algorithms and Adaptive Simulated Annealing algorithms were under investigation in combination with three meta-modeling techniques.

This paper focuses on developing an advanced analytical tire-terrain interaction model for full vehicle performance prediction purposes. The truck tire size 315/80R22.5 is modeled using the Finite Element Analysis (FEA) technique and validated against manufacturer experimental data in static and dynamic domains. While the terrain is modeled using Smoothed-Particle Hydrodynamics (SPH) technique and calibrated using experimental results of pressure-sinkage and direct shear tests. The contact between the FEA tire model and the SPH soil model is defined using the node symmetric node to segment with the edge treatment algorithm. The model setup consists of four tires appended back to back over a box filled with soil particles to represent a multi-axle off-road truck. The distances between the four tires are similar to the distances between the four axles of an off-road truck.

Slip or relative rotation between the tire and rim is a significant concern for vehicle operation and wheel manufacturing since it leads to wheel imbalance and vibration as well as power losses. A slip situation typically occurs due to improper bead lubrication and mounting, irregularities in the bead seat, and extreme loading conditions with high torques and low tire pressures. Currently, there are relatively few published studies on the tire-rim interface, and they mainly focus on topics such as the mounting process, load transfer, and friction modelling. This leaves a gap to explore the measurement and variation of gross tire-rim slip under the dynamic conditions of a driven tire. In this paper, a previously developed and validated FEA truck tire model was modified to include a frictional contact surface between the tire and rim, and then the slip ratio between the tire and rim was measured under different operating conditions.

This paper investigates the tire-road interaction for tires equipped with two different solid rubber material definitions within a Finite Element Analysis virtual environment, ESI PAMCRASH. A Mixed Service Drive truck tire sized 315/80R22.5 is designed with two different solid rubber material definitions: a legacy hyperelastic solid Mooney-Rivlin material definition and an Ogden hyperelastic solid material definition. The popular Mooney-Rivlin is a material definition for solid rubber simulation that is not built with element elimination and is not easily applicable to thermal applications. The Ogden hyperelastic material definition for rubber simulations allows for element destruction. Therefore, it is of interest and more suited for designing a tire model with wear and thermal capabilities.

This paper focuses on predicting the rolling resistance and hydroplaning of a wide base truck tire (Size: 445/50R22.5) on dry and wet surfaces. The rolling resistance and hydroplaning are predicted at various inflation pressures, loads, velocities, and water depths. The wide base truck tire was previously modeled and validated using Finite Element Analysis (FEA) technique in virtual performance software (Pam-Crash). The water is modeled using Smoothed-Particle Hydrodynamics (SPH) method and Murnaghan equation of state. A water layer is first built on top of an FEA rigid surface to represent a wet surface. The truck tire is then inflated to the desired pressure. A vertical load is then applied to the center of the tire. For rolling resistance tests variable constant longitudinal speeds are applied to the center of the tire. The forces in the vertical and longitudinal directions are computed, and the rolling resistance is calculated.