Experimentally determined material parameters for temperature prediction of an automobile tire using finite element analysis

CITATION: Van Blommestein, W. B., Venter, G. & Venter, M. P. 2019. Experimentally determined material parameters for temperature prediction of an automobile tire using finite element analysis. R & D Journal of the South African Institution of Mechanical Engineering, 35:21-30, doi:10.17159/2309-8988/2019/v35a3.The original publication is available at https://www.saimeche.org.zaThe material parameters of an automotive truck tire were experimentally determined and validated for use in a thermal finite element analysis to determine the temperature distribution in the tire due to different operating conditions. Uni-axial tensile tests were performed on tire samples. The force displacement response of each was used to determine material properties by means of direct curve-fitting and iterative numerical procedures. Equivalent finite element simulation models were used to validate the properties. Hysteresis behaviour of the rubber regions were identified by dynamic mechanical analysis. Material definitions were incorporated into a finite element model to predict the steady-state heat generation and temperature distribution within a tire due to hysteresis. Experimental rolling tire temperature measurements were taken on a test bench. A comparison of the results with those obtained from the equivalent thermal models was used to validate the numerical models.https://www.saimeche.org.za/page/RD_2019Publisher's versio

三浦春恵先生の略歴と業績

Tema diplomskog rada je analiza gumenog elementa rastojnika-prigušivača pomoću metode konačnih elemenata, u svrhu dobivanja elastičnih parametara materijala gumenog elementa. U radu je opisana pojava aeolskih vibracija vodiča dalekovoda i osnovni tipovi rastojnika-prigušivača. Definirani su tipovi strukturne nelinearnosti (geometrijska, materijalna, nelinearnost uslijed kontakta). Prikazan je razvoj kontaktne mehanike, opisane su vrste kontakata i objašnjene postavke za definiranje kontakta u programskom paketu Abaqus. Objašnjene su geometrijska i materijalna nelinearnost te opisane specifičnosti jednadžbi koje se koriste u analizi hiperelastičnih materijala (gume) Za svaki tip nelinearnosti verificirani su konačni elementi usporedbom numeričkih rješenja s referentnim rješenjima. U nastavku su prikazani rezultati eksperimenta izvršenog na gumenom elementu. Napravljen je nelinearni numerički model u programskom paketu Abaqus te je opisan tijek izrade modela. Preklapanjem rezultata numeričke analize i eksperimenta dobiveni su elastični parametri materijala gumenog elementa rastojnika-prigušivača.The subject of this thesis is the analysis of the spacer-damper rubber element using the finite element method, in order to determine the rubber element elastic material parameters. The thesis describes the phenomenon of the power line aeolian vibration and basic types of spacer-dampers. Types of structural nonlinearity (geometric, material, nonlinearity due to contact) are defined through thesis. In thesis, the development of contact mechanics is shown, the types of contacts are described and the settings to define the contact in software program Abaqus are explained. The geometric and material nonlinearity are explained and the specifics of the equations used in the analysis of hyperelastic materials (rubber) are described. Each type of nonlinearity finite elements is verified by comparing the numerical and reference results. At the end of the thesis, the results of experiments performed on the rubber element are shown. The making of nonlinear numerical model has been described and then calculated in software program Abaqus. Elastic material parameters of the spacer-damper rubber element where determined through comparison of the numerical analysis and experimental results

Application of the method finite elements by numerical modeling stress-strain state in conveyor belts

Solving problems connected with damaging a conveyor belt at the transfer points is conditioned by knowing laws of this phenomenon. Acquiring the knowledge on this phenomen is possible to be gained either by experimental research or by the numerical model GEM 22, which enables to determine the distribution of stresses and strains in a suitably selected cross-section of a conveyor belt. The paper begins by defining the problem, determining the boundary model conditions and continues by modelling the dynamic force acting on the conveyor belt. In the conclusions of the paper there are given table and graphical results of the numerical modelling aimed at solving the problems connected with the damaging of a conveyor belt. By numerical modelling, in this case the finite element method, in the given way can be realized the parametric studies with changing values of input parameters, especially: - stretching force, - thickness of cover layers of the conveyor belt and strain properties of the rubber, - parameters of the steel cord of the conveyor belt

Tensile stress-strain characteristics of rubberised concrete from flexural tests

The tensile characteristics of rubberised concrete are practically impossible to obtain from direct tensile tests, due to the non-uniform distribution of aggregates and stiffness. In this paper, notched three-point bending tests are used to characterise Mode I fracture behaviour of concrete incorporating high volume of rubber particles obtained from post-consumer tyres. The test results show that rubber particles enhance energy absorption capacity and ductility of concrete. Inverse finite element analysis is performed to indirectly determine tensile stress-strain curves of rubberised concrete. The key material parameters introduced in the constitutive model are tensile strength, fracture energy and crack band width. The spurious mesh dependency is resolved by adopting a simple modification to the softening modulus as a function of element size. The performance of the proposed tensile stress-strain relation is compared with that of Model Code 2010 using ABAQUS concrete damaged plasticity model and shows considerably better accuracy. The proposed model can be used to improve the reliability of numerical analyses of rubberised concrete elements and structures

Cyberbullying among youth in Malaysia

The purpose of this research was to survey the current situation concerning cyberbullying among youth in Malaysia. Specifically, this research aimed at finding out the prevalence of cyberbullying among youth based on demographic data and the common types of cyberbullying tactic. The survey method was adopted as the research design in which a set of questionnaire was developed to collect the data. A total of 1406 respondents were selected in this research. In general, the research findings reveal that majority of the respondents had been cyberbullied before. The Malays community yielded the highest percentage of cyberbullied victims. In addition, the result also shows that female cyber users were usually targeted as the cyberbully victim. The most common type of cyberbully tactic was through receiving offensive/ pornographic materials. Effective and pragmatic steps have to be taken in order to mitigate the cyberbullying problem among Malaysian youth

Characterization of defect induced multilayer graphene

A study of oxygen plasma on multilayer graphene is done with different flow rates. This is to allow a controlled amount of defect fabricated on the graphene. Results from the study showed that the intensity ratio of defect between D peak and G peak was strongly depended on the amount of oxygen flow rate thus affected the 2D band of the spectra. The inter-defect distance LD ≥ 15 nm of each sample indicated that low-defect density was fabricated. The surface roughness of the multilayer graphene also increased and reduced the conductivity of the multilayer graphene

Static tire properties analysis and static parameters derivation to characterising tire model using experimental and numerical solutions

Tire-ground interaction plays substantial role in determining vehicle kinetics and kinematics yet a clear understanding of such an interaction outputs is complex process. The present study aims at static analysis of tire parameters using both experimental and numerical based finite element method (FEM) solutions. To this end, tire cross section shape with different inflation pressures, vertical stiffness together with the footprint were measured using controlled apparatus and then are compared with the simulation results in order that the accuracy of the FE tire model in static condition can be validated. The 3D tire model was obtained by revolving the 2D axisymmetric tire model, and static stiffness and footprint were predicted using the 3D model. Inflation pressure analysis was presented by comparing the tire cross-section shape variation at different inflation pressures. The conclusions will serve future investigations as a concise knowledge source to develop improved tire models

Development of engineering design tools to help reduce apple bruising

A large percentage of apples are wasted each year due to damage such as bruising. The apple journey from orchard to supermarket is very complex and apples are subjected to a variety of static and dynamic loads that could result in this damage occurring. The main aim of this work was to carry out numerical modelling to develop a design tool that can be used to optimise the design of harvesting and sorting equipment and packaging media to reduce the likelihood of apple bruise formation resulting from impact loads. An experimental study, along with analytical calculations, varying apple drop heights and counterface material properties, were used to provide data to validate the numerical modelling. Good correlation was seen between the models and experiments and this approach combined with previous work on static modelling should provide a comprehensive design tool for reducing the likelihood of apple bruising occurring

Visco-hyperelastic model with damage for simulating cyclic thermoplastic elastomers behavior applied to an industrial component

In this work a nonlinear phenomenological visco-hyperelastic model including damage consideration is developed to simulate the behavior of Santoprene 101-73 material. This type of elastomeric material is widely used in the automotive and aeronautic sectors, as it has multiple advantages. However, there are still challenges in properly analyzing the mechanical phenomena that these materials exhibit. To simulate this kind of material a lot of theories have been exposed, but none of them have been endorsed unanimously. In this paper, a new model is presented based on the literature, and on experimental data. The test samples were extracted from an air intake duct component of an automotive engine. Inelastic phenomena such as hyperelasticity, viscoelasticity and damage are considered singularly in this model, thus modifying and improving some relevant models found in the literature. Optimization algorithms were used to find out the model parameter values that lead to the best fit of the experimental curves from the tests. An adequate fitting was obtained for the experimental results of a cyclic uniaxial loading of Santoprene 101-73