This research work is devoted to development of a non-linear finite element model for a bias tire under inflation pressure and Contact loads. The model was developed by a pre-processor program for NSTAR which is the nonlinear module of COSMOS/M software. Three-dimensional isoparametric brick elements with total Lagrangian formulation have been used to construct the finite element mesh of the tire model. Applying appropriate rim displacement toward a rigid surface simulated the Contact load. The stress-strain relationships of composite sections (plies, breaker and bead) are described by linear orthotropic constitutive equation while Mooney-Rivlin incompressible model was used for the description of the behaviour of rubbery parts. The analysis was performed in a Lagrangian framework to take the geometrical non-linearity of large deformation of tire into account in conjunction with Newton-Raphson iterative procedure to solve the final set of working equations. Comparisons of the numerical results with laboratory measured tire deformations and also available tire Standards, confirm the general suitability of the developed mathematical model.

A plain strain analysis of frictional rolling Contact on an elastic graded coating is presented in this paper. Finite element method is applied to gain an understanding of the stresses and Contact zone properties caused during rolling Contact. The effects of friction, material stiffness ratio and coating thickness on stresses in Contact zone and coating/substrate interface are studied. Shear modulus of softening and stiffening graded coatings change with exponential, power law and linear functions. The substrate is homogenous and the rigid cylindrical roller moves in a steady state condition with constant velocity. The coating is modeled in multi layers and a 2-D hard Contact of rolling surfaces is considered. The analytical results verify the present method and show a good agreement. It is shown that thinner thicknesses have more effects on stresses and energy density, but these effects are not seen for thicknesses larger than a specific limit.

In the field of wheel-rail Contact, many researches have been done into rolling profiles in this paper, three wheels from passenger wagons and two standard rails UIC60 and U33 are considered. The calculation of Contact parameters including Contact surface dimensions, stress, and pressure makes it possible to investigate wheel and rail profile conformity in different Contact conditions including straight track, curving, and crossing. Hertz Contact method and finite element analysis were used for this purpose. The comparison of mentioned parameters for six pairs of wheel and rail was conducted. The results show that in the case of straight track and curving wheel III has smaller Contact stresses and pressures but in the case of crossing wheel I represents an acceptable performance in Contact with rail UIC60. Taken together, the results indicate a weak performance of rail U33 in all cases.

The purpose of this work is to present a study of the thermomechanical behavior of the automotive disc brake during the braking phase. The first analysis is performed on the disc-pad model without the presence of thermal properties. Structural performance of the disc-pad model such as deformation and Von-Mises stress is predicted. The case of thermoelasticity on the same model with the inclusion of convection, adiabatic and heat flux elements were also studied. The prediction results of temperature distribution, deformation, stress and Contact pressure are presented. Furthermore, the structural performances between the two analyses (mechanical and thermomechanical) were compared as well. The results of this investigation may assist brake engineers to choose a suitable analysis in order to critically evaluate structural and Contact behaviour of the disc brake assembly.

Different types of Contact, including Contact between node pairs, any-Contact of nodes, and Contacts of the entire network, are used to characterize social relations in mobile social networks. Different modes of routing, from the point of view of message delivery semantics, encompass unicasting, multicasting, any-casting, and broadcasting. Studies have shown that using probability distribution functions of Contact data, which is mainly assumed to be homogeneous for nodes, improves the performance of these networks. However, there exists an important challenge in studies on distributions. A lot of works apply the distribution of one type of Contact to other types. Hence in routing applications, it causes to use of the distribution of one type of Contact for any mode of routing. This study provides a complete solution to model each type of homogeneous Contact data distribution and to use them in different modes of routing. We propose a routing algorithm that uses this new model. Results show that our solution improves the average latency of comparing methods Epidemic, TCCB, and DR about 3.5-times, 30%, and 45%, respectively. It achieves a delivery rate of about 5% and 6%, and average latency about 6% and 8% better than that of DR and TCCB, respectively.

Pounding of adjacent building have been seen in the moderate and strong earthquakes. There are different methods to model the impact. One of these methods is Contact elements. Contact elements include linear and nonlinear elastic and viscoelastic and Hertz-damp elements. Investigators have generally studied on Contact elements in elastic structures. In this study, the ability of different Contact modelings is added to Opensees software. Validation of modeling is achieved by comparing the numerical result of this study with other investigations' numerical studies. Simulations between analytical modeling and experimental studies show that to conquer displacement, results of different Contact elements are the same, but velocity and Contact force results of elements with and without damping have more accuracy. Finally these elements are used to model the Contact of 5-story building under 6 records, in two left to right and right to left states. As regards, Hertz-damp has the least uncertainty of modeling; therefore results of other elements are compared with this element. Results generally show that accuracy of nonlinear elements is more than linear elements. This is more obvious in the maximum Contact forces.

Multi-layer steel (MLS) cylinder head gaskets (CHG) are widely used to seal the engine cylinder head. Therefore, the interaction between the engine cylinder head, cylinder block and the cylinder head gasket is very important from technical point of view. To avoid the escaping gas from the engine affecting the overall performance of the engine during operation, both the pre-stressing force of the bolts as well as the gasket design are critical factors in enhancing the efficiency of the sealing of the gasket.In this paper the finite element method (FEM) is used to investigate the interaction between the cylinder head and the cylinder block. Furthermore the distribution of the Contact pressure on the gasket and the cylinder head and the cylinder block stresses at different condition, such as cold assembly, hot assembly, cold start, firing, engine cooling down to 20o(c) and -25°(c) are calculated. The validation is performed using Fuji paper test and thermal survey test. The results revealed that the sealing pressure on the gasket strongly depends on the pre-stressing force of the bolts. However, the location of minimum Contact pressure on the gasket is changed by considering the thermal loading.

This paper addresses the finite element modelling of a steel belted radial tyre under static Contact load using ABAQUS code. The model combines the 3D parts of the complex tread patterns and the quasi axisymmetric part of the tyre in which the tread blocks are not included. These two sections were meshed separately and linked together using a tying algorithm implemented in the code. The fibber reinforced parts of the tyre including ply, belts, and cap ply were modelled using rebar layer embedded in the surface elements. A hyperelastic material model was used in conjunction with a linear elastic one to describe the stress-strain behaviour of rubber and reinforcing fibres, respectively. The developed model was used to simulate the 175/70R14 steel-belted radial tyre subjected to inflation and Contact loads. Three belts angles were selected to examine the effect of belt angle variations on the mechanical behaviour of the tyre. In addition, the results were also compared with a similar tyre model in which a simply ribbed tread was used instead of complex tread pattern. The friction between tread surface and Contact road surface was simulated using the Coulomb’s friction law. The numerical results and also the comparison of experimentally measured tyre deflection under concentrated vertical load revealed that neglecting the details of the tread blocks has very minor effect on the predicted tyre deformation. However, differences can be large enough when considering secondary or higher variables such as Contact pressure, stress, and strain energies. It is also shown that a belt angle of 20o is the best comprised value among the selected design parameters.

In this research, the new concept of ‘ bolted joint affected region (BJAR)’ is introduced to simulate dynamical behavior of bolted lap joints. Such regions are modeled via special elements called Contact zone element (CZE) which unify the neighboring Contact surfaces of substructures. These elements are different from the thin layer interface elements that form an individual layer between the two substructures. The CZEs have no specified elastic characteristics. They are thus different from the adjoining solid elements and the constitutive relation for them is prescribed in normal and shear components. The unknown parameters of the model can be identified throughout model updating with modal test data. The structure’ s frequency response function (FRF) is measured by excitation with an impact hammer and the measured responses are compared with model predictions including the CZEs’ parameters. The difference between the measured and predicted frequencies is minimized as the objective function. The optimized thickness and density are considered in addition to the elastic properties of BJAR. The competency of the proposed procedure is verified with modeling an actual structure containing a single lap bolted joint coupling two identical structural steel beams. The results showed proper conformity with model predictions. This model can be incorporated into the commercial finite element codes to simulate bolted joints for large and complex structures considering its accuracy and computationally efficient manner.