Fredrik Öijer

Prediction of rolling resistance and steering characteristics using finite element analysis truck tyre model

The purpose of this research is to provide insight into the design and development of a finite element analysis (FEA) model of a heavy truck tyre for the purpose of investigating rolling resistance and steering characteristics. Aspects considered include the effects of design parameters (tyre dimensions, construction, materials, and FEA modelling technique) and operating parameters (tyre inflation pressure, vehicle speed, spindle load, and road surface texture). The model was also developed to predict the effects of combined steering and camber angles on cornering forces, aligning and overturning moments. The findings of this investigation show that the multi-layer membrane material can accurately simulate the tyre carcass structure. Validation tests include the static load-deflection test and dynamic cleat-drum excitation test. The experimental data shows that the generated FEA tyre and wheel model qualitatively simulates a real heavy truck radial tyre. Further work is required to allow for accurate quantitative prediction and would vary largely with tyre construction.

Development of FEA tyre/soil interaction model using SPH and hybrid SPH/FEA technique

One of the most accurate methods for simulating numerous nonlinear systems is finite element analysis (FEA). However, when it comes to modelling non-meshed particles, smoothed particle hydrodynamics (SPH) is used to obtain more reliable results. The modelled FEA truck tyre is similar to a wide base truck tyre having specifications of 445/50R22.5. The tyre is previously validated through different simulations such as contact foot print, static deflection, dynamic first mode of vibration, and various rolling resistance tests. These simulations are performed under different inflation pressures, vertical loads, and speeds. In this research, the tyre is validated on soft soil, while considering various combinations of parameters. These parameters affect soil characteristics to reach an optimum and calibrated soil model corresponding to the existing empirical data for dry sand. This research will be heading toward developing an off-road rigid ring model in future projects.

Sensitivity Analysis of Smoothed Particle Hydrodynamics in PAM-CRASH for Modeling of Soft Soils

The rapid progression of computational power and development of non-mesh particle modeling techniques provides solutions to problems which are not accurately modeled using traditional finite element analysis techniques. The field of soft soil modeling has been pressing on in recent years and the smoothed particle hydrodynamics (SPH) modeling method in PAM-CRASH provides opportunity for further advancement in accuracy.This research focuses on the development of soft soil models using SPH with verification using pressure-sinkage and shear strength criterion. Soil model parameters such as geometry and contact model are varied to determine the effect of the parameters on the behaviour of the soft soil and relationships are developed. The developed virtual soil models are compared against existing soils to determine which soils are accurately modeled and further refinements are made to validate the models with existing empirical data.Copyright

Design and development of a road profile generator

This work aims to develop a method of generating a random road profile in three-dimensional space based on existing road design and classification standards and parameters, such examples being the Volvo Global Transport Application (GTA) and the International Organization of Standards (ISO). This is done by combining probability models, statistical distributions and mathematical methods of defining road curves, elevation and surface roughness through the use of MATLAB code. The proposed road profile generator code creates a road in three-dimensional space independent of vehicle characteristics and behaviour. The ultimate goal of this work is to contribute to the capabilities of modern virtual vehicle simulation systems by incorporating more random environments with respect to a wide range of established national standards to better simulate real driving loads.

FEA Tire Modeling and Validation Techniques

Recent advances in power and efficiency of computerized modeling methods has made it easier to develop accurate tire models. These newer models are now created with such accuracy that it has become easy to predict the experimental tire’s behavior and characteristics. These models are helpful with determining tire, tire-road, and tire-soil interaction properties. By creating virtual models, the overall capital for research and development can be reduced as well as replacing unavailable experimental tires for research.This research paper mainly focuses on the validation of computer generated FEA tire models which are then used for the prediction of the experimental tire’s rolling resistance, static and dynamic characteristics. Experimental data, such as rolling resistance and vertical acceleration are used in validation simulations in order to tune the virtual model to match the experimental tire’s behavior. The tire that was used for this research is a six-groove 445/50R22.5 FEA truck tire, which was constructed and validated over the course of this research.Copyright

Prediction of Tire Ground Interaction Using FEA Truck Tire Models

The advancement of computerized modeling has allowed for the creation of extensive pneumatic tire models. These models have been used to determine many tire properties and tire-road interaction parameters which are either prohibitively expensive or unavailable with physical models.This paper focuses on the prediction of tire-ground interaction with emphasis on individual and combined effect of tire slip angle and camber angle at various operating parameters. The forces generated at tire contact such as rolling resistance, cornering force, aligning moment and overturning moment can be predicted and used to optimize the tire design parameters. In addition to above stated, the three-groove FEA truck tire model representing radial-ply tire of size 295/75R22.5 was used in vertical load deflection test to determine enveloping characteristics under various load conditions and inflation pressures.Copyright