Modeling of braking thermal effect for wheel-rail contact parameters

2020 ◽  
pp. 095440972096925
Author(s):  
Molla Derbew ◽  
DK Nageswara Rao ◽  
Ephrem Zeleke
Keyword(s):  
Finite Element Analysis ◽  
Shear Stress ◽  
Thermal Effect ◽  
Mechanical Loading ◽  
Thermal Loading ◽  
Mechanical Load ◽  
Hertzian Contact ◽  
Element Analysis ◽  
Hertz Theory ◽  
Contact Parameters

The Hertzian contact parameters are evaluated by taking into account the increase in temperature of the wheel due to braking under a steady mechanical loading. An equivalent mechanical load is evolved by Finite Element Analysis (FEA) to produce the same effect of the mechanical and thermal loading. The values obtained by FEA and Hertz theory for steady mechanical loading as well as for equivalent mechanical loading are matching. The contact parameters are found to vary linearly with temperature and equations are developed to obtain these parameters under thermal and mechanical loading. For 146.3 °C temperature of wheel due to braking, the contact pressure is 941.3 MPa, shear stress is 378 MPa and for solo mechanical loading, they are 519.8 MPa and 191 MPa correspondingly. The area of contact patch has increased from 0.0652 m2 to 0.142 m2 by 2.2 times due to thermal effect.

scholarly journals Deflection calculation of cam profile due to a Hertzian contact pressure

2020 ◽  
Vol 37 ◽  
pp. 149-160
Author(s):  
Louay S Yousuf
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Response ◽  
Contact Pressure ◽  
Reduction Rate ◽  
Hertzian Contact ◽  
Element Analysis ◽  
Cam Profile ◽  
The Impact ◽  
Contact Parameters

Abstract The bending deflection of cam profile was analyzed for three paths of contact and distinct Hertzian contact pressure. The impact happened between the disc cam and roller follower based on the contact parameters. The contact parameters are contact body stiffness, sliding contact velocity, exponent and penetration. A disc cam and roller follower system were discussed and analyzed for the dynamic response of the follower and bending deflection of the cam profile. The objective of this paper was to study the effect of contact load on the bending deflection. A system with spring stiffness (k) and viscous damping coefficient (c) at the end of the follower stem was used to reduce the bending deflection on the cam profile. The theory of circular plate was applied to derive the analytic solution of the bending deflection. The dynamic response of the follower had been determined by using the SolidWorks software based on the contact parameters. The experimental setup was done through an infrared camera device. Finite-element analysis was used to calculate the bending deflection of the cam profile numerically. Finite-element analysis was carried out by using the ANSYS version 19.2 package. The analytic and simulation results are checked and verified for bending deflection at the point of contact. The reduction rate for bending deflection was 73.425% for path no. (1), 85.925% for path no. (2) and 61.467% for path no. (3).

Finite Element Analysis of a Gasketed Flange Joint Under Combined Internal Pressure and Thermal Transient Loading

2007 ◽  
Author(s):  
Muhammad Abid ◽  
Javed A. Chattha ◽  
Kamran A. Khan
Keyword(s):  
Finite Element Analysis ◽  
Steady State ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Transient Loading ◽  
Thermal Transient ◽  
Transient Thermal ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. In the available published work, thermal behavior of the pipe flange joints is discussed under steady state loading with and without internal pressure and under transient loading condition without internal pressure. The present design codes also do not address the effects of steady state and thermal transient loading on the structural integrity and sealing ability. It is realized that due to the ignorance of any applied transient thermal loading, the optimized performance of the bolted flange joint can not be achieved. In this paper, in order to investigate gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and transient thermal loading, an extensive nonlinear finite element analysis is carried out and its behavior is discussed.

Finite Element Study of the Effect of Load Sequence on the Fretting Wear

2020 ◽  
Author(s):  
Pankaj Dhaka ◽  
Raghu V. Prakash
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fretting Wear ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Low Load ◽  
Dimensional Finite Element ◽  
Wear Modelling ◽  
Load Sequence ◽  
Contact Parameters

Abstract Understanding the effect of load sequence is important in the context of a blade-disc dovetail joint in an aero-engine and many other such applications where, the mating surfaces undergo fretting wear under variable slip amplitude loading conditions. In the present work, a two-dimensional finite element analysis is carried out for a cylinder-on-plate configuration. The cylinder is modeled as deformable whereas the plate is modelled as rigid. An incremental wear modelling algorithm is used to model the wear of cylindrical pad while the plate is assumed as un-worn. This simulates a practical scenario where, generally one of the mating surfaces is sufficiently hardened or an interfacial harder/sacrificial element is inserted to restrict the wear to only one of the surfaces. A Fortran-based ABAQUS® subroutine UMESHMOTION is used to simulate the wear profile for the cylinder. A constant extrapolation technique is used to simulate 18000 cycles of fretting. The finite element analysis results are validated with the analytical solutions and literature data. The fretting wear modelling is carried out for two different slip amplitudes viz., 25 μm and 150 μm, to simulate the low and high slip amplitude loading respectively. Two blocks of alternate low and high slip amplitudes are applied to understand the influence of load sequence. Important contact parameters viz., contact pressure, contact stresses and contact slip are extracted. A comparison is made between the low-high and high-low load sequence based on the contact tractions and worn out profiles.

3D finite element analysis on esthetic indirect dental restorations under thermal and mechanical loading

2010 ◽  
Vol 48 (11) ◽  
pp. 1107-1113 ◽  
Author(s):  
Tulimar P. M. Cornacchia ◽  
Estevam B. Las Casas ◽  
Carlos Alberto Cimini ◽  
Rodrigo G. Peixoto
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Loading ◽  
Element Analysis ◽  
3D Finite Element ◽  
3D Finite Element Analysis ◽  
Dental Restorations

Approximate method for the analysis of components undergoing ratchetting and failure

1998 ◽  
Vol 33 (1) ◽  
pp. 55-65 ◽  
Author(s):  
J Lin ◽  
F P E Dunne ◽  
D R Hayhurst
Keyword(s):  
Approximate Method ◽  
Mechanical Loading ◽  
Thermal Loading ◽  
Cyclic Plasticity ◽  
Processing Unit ◽  
Computationally Efficient ◽  
Element Analysis ◽  
Cyclic Thermal Loading ◽  
Central Processing ◽  
Practical Design

An approximate method has been presented for the design analysis of engineering components subjected to combined cyclic thermal and mechanical loading. The method is based on the discretization of components using multibar modelling which enables the effects of stress redistribution to be included as creep and cyclic plasticity damage evolves. Cycle jumping methods have also been presented which extend previous methods to handle problems in which incremental plastic straining (ratchetting) occurs. Cycle jumping leads to considerable reductions in computer CPU (central processing unit) resources, and this has been shown for a range of loading conditions. The cycle jumping technique has been utilized to analyse the ratchetting behaviour of a multibar structure selected to model geometrical and thermomechanical effects typically encountered in practical design situations. The method has been used to predict the behaviour of a component when subjected to cyclic thermal loading, and the results compared with those obtained from detailed finite element analysis. The method is also used to analyse the same component when subjected to constant mechanical loading, in addition to cyclic thermal loading leading to ratchetting. The important features of the two analyses are then compared. In this way, the multibar modelling is shown to enable the computationally efficient analysis of engineering components.

Fatigue surviving, fracture resistance, shear stress and finite element analysis of glass fiber posts with different diameters

2015 ◽  
Vol 43 ◽  
pp. 69-77 ◽  
Author(s):  
Vinícius Felipe Wandscher ◽  
César Dalmolin Bergoli ◽  
Ariele Freitas de Oliveira ◽  
Osvaldo Bazzan Kaizer ◽  
Alexandre Luiz Souto Borges ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Glass Fiber ◽  
Fracture Resistance ◽  
Element Analysis ◽  
Fiber Posts ◽  
Glass Fiber Posts ◽  
Different Diameters

Investigation of Design Parameters and Failure Criteria of O-Ring Seal Structure

2005 ◽  
Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Quanbin Ren ◽  
Jie Hong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Normal Stress ◽  
Maximum Shear Stress ◽  
Design Parameters ◽  
Element Analysis ◽  
Axisymmetric Model ◽  
Sealing Performance ◽  
Maximum Contact

First, this paper established the seal structural 2D axisymmetric model of a certain Solid Rocket Booster (SRB) and calculated the deformation and stresses at ignition through a large displacement, incompressible, contact finite element analysis. The results show that the maximum contact stress appears at the contact area and the maximum shear stress at groove notch. Then, some typical parameters of the seal structure which might have the impact on the sealing performance, such as the gap breadth, initial compressibility, fillets of the groove notch and bottom, groove width, were analyzed. We can find that the gap breadth and initial compressibility do great contributions to the maximum contact normal stress, and the groove notch and bottom fillets act upon the maximum shear stress obviously. In order to verify the validity of the 2D axisymmetric model, 3D structural finite element analysis of the structure was conducted, and the results indicate that in service, the upper flange is inclined relative to the nether flange, which seems to mean that the gap breadth can not be considered as a constant during the 2D axisymmetric analysis. However further calculations say that if using the minimum gap breadth gotten in 3D analysis as its constant gap value, the above 2D axisymmetric model can rationally take the place of 3D model to analyze the sealing performance. Finally, the failure modes & criteria of the O-ring seals based on the maximum contact normal stress and shear stress were determined to ensure the reliability of this structure.

Finite Element Analysis of Local Inelastic Strain Based on Stress Redistribution Locus

2008 ◽  
Author(s):  
Shunji Kataoka ◽  
Takuya Sato
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Loading ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
Pressure Vessels ◽  
Stress Redistribution ◽  
Strain Diagram ◽  
Element Analysis ◽  
Inelastic Analysis

Creep-fatigue damage is one of the dominant failure modes for pressure vessels and piping used at elevated temperatures. In the design of these components the inelastic behavior should be estimated accurately. An inelastic finite element analysis is sometimes employed to predict the creep behavior. However, this analysis needs complicated procedures and many data that depend on the material. Therefore the design is often based on a simplified inelastic analysis based on the elastic analysis result, as described in current design codes. A new, simplified method, named, Stress Redistribution Locus (SRL) method, was proposed in order to simplify the analysis procedure and obtain reasonable results. This method utilizes a unique estimation curve in a normalized stress-strain diagram which can be drawn regardless of the magnitude of thermal loading and constitutive equations of the materials. However, the mechanism of SRL has not been fully investigated. This paper presents results of the parametric inelastic finite element analyses performed in order to investigate the mechanism of SRL around a structural discontinuity, like a shell-skirt intersection, subjected to combined secondary bending stress and peak stress. This investigation showed that SRL comprises a redistribution of the peak and secondary stress components and that although these two components exhibit independent redistribution behavior, they are related to each other.

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