Finite Element Based Analysis of Reinforcing Cords in Rolling Tires: Influence of Mechanical and Thermal Cord Properties on Tire Response

2018 ◽  
Vol 46 (4) ◽  
pp. 294-327 ◽  
Author(s):  
Ronny Behnke ◽  
Michael Kaliske
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Temperature Distribution ◽  
Design Parameters ◽  
Model Parameters ◽  
Mechanical And Thermal Properties ◽  
Vertical Force ◽  
Passenger Cars ◽  
Vertical Stiffness ◽  
Steady State Rolling

ABSTRACT Tires of passenger cars and other special tires are made of rubber compounds and reinforcing cords of different type to form a composite with distinct mechanical and thermal properties. One of the major load cases is the steady state rolling operation during the tire's service. In this contribution, attention is paid to the strain and force state as well as the temperature distribution in the carcass cord layer of a steady state rolling tire. A simple benchmark tire geometry is considered, which is made of one rubber compound, one carcass cord layer (textile), and two belt cord layers (steel). From the given geometry, two tire designs are derived by using two distinct types of reinforcing cords (polyester and rayon) for the carcass cord layer. Subsequently, the two tire designs are subjected to three load cases with different inner pressure, vertical force, and translational velocity. The strain and the force state as well as the temperature distribution in the cords are computed via a thermomechanically coupled finite element simulation approach for each tire design and load case. To realistically capture the thermomechanical behavior of the cords, a temperature- and deformation-dependent nonlinear elastic cord model is proposed. The cord model parameters can be directly derived from data of cord tensile tests at different temperatures. Finally, cord design parameters (minimum and maximum strains and forces in the cords, maximum strain and force range per cycle, and maximum cord temperature) are summarized and compared. Additionally, the global vertical stiffness and the rolling resistance for each tire design are addressed.

scholarly journals Reducing car audio button noise while maintaining tactile quality

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775259
Author(s):  
Hyo-Chan Kwon ◽  
Chang-Hee Cho ◽  
Cheong-Wu Nam ◽  
Soo-Won Chae ◽  
Seong-Yun Seo ◽  
...  
Keyword(s):  
Finite Element ◽  
Design Parameters ◽  
Model Parameters ◽  
Finite Element Analyses ◽  
Passenger Cars ◽  
Cabin Noise ◽  
Prototype Test ◽  
Subsequent Response ◽  
Car Audio ◽  
Improved Design

Recently, interior noise levels of passenger cars have been significantly reduced. The reduction of major cabin noise led to the recognition of small noises that are previously unnoticed. Specifically, the button noises of electrical devices in passenger compartments have been identified as belonging to this category of noise. The aim of this study is to improve the auditory quality of a car audio button while maintaining its tactile quality that is familiar to users. The tactile and auditory qualities can be described by the load versus stroke characteristics and the operation noise level. For buttons with rubber domes, the buckling behavior of the domes governs the tactile and auditory qualities. To preserve the tactile quality, the sensitivity of load versus stroke characteristics to each of the eight identified parameters is obtained from the finite element analyses using model parameters varied by ±10%. Four parameters to which the tactile quality was insensitive are selected. To identify the contributions of these four design parameters to auditory quality, finite element analyses were performed in conjunction with design of experiments. The improved design obtained by the subsequent response surface methodology optimization was validated by a prototype test with a 12 dBA reduction in noise.

Hysteresis Heating of Railroad Bearing Thermoplastic Elastomer Suspension Element

2017 ◽  
Author(s):  
Oscar O. Rodriguez ◽  
Arturo A. Fuentes ◽  
Constantine Tarawneh ◽  
Robert E. Jones
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steady State ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Internal Heat ◽  
Thermoplastic Elastomer ◽  
Internal Heat Generation ◽  
Element Analysis ◽  
Railroad Bearing

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict its dynamic response and structural integrity, as well as, to predict and understand the heat transfer paths from bearings into the truck assembly and other contacting components. This study investigates the internal heat generation in the suspension pad and its impact on the complete bearing assembly dynamics and thermal profile. Specifically, this paper presents an experimentally validated finite element thermal model of the elastomeric pad and its internal heat generation. The steady-state and transient-state temperature profiles produced by hysteresis heating of the elastomer pad are developed through a series of experiments and finite element analysis. The hysteresis heating is induced by the internal heat generation, which is a function of the loss modulus, strain, and frequency. Based on previous experimental studies, estimations of internally generated heat were obtained. The calculations show that the internal heat generation is impacted by temperature and frequency. At higher frequencies, the internally generated heat is significantly greater compared to lower frequencies, and at higher temperatures, the internally generated heat is significantly less compared to lower temperatures. However, during service operation, exposure of the suspension pad to higher loading frequencies above 10 Hz is less likely to occur. Therefore, internal heat generation values that have a significant impact on the suspension pad steady-state temperature are less likely to be reached. The commercial software package ALGOR 20.3TM is used to conduct the thermal finite element analysis. Different internal heating scenarios are simulated with the purpose of obtaining the bearing suspension element temperature distribution during normal and abnormal conditions. The results presented in this paper can be used in the future to acquire temperature distribution maps of complete bearing assemblies in service conditions and enable a refined model for the evolution of bearing temperature during operation.

Structural Stiffness of Tire Calculated From Strain Energy

2015 ◽  
Author(s):  
Namcheol Kang ◽  
Jong-Jin Bae ◽  
Jong Beom Suh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Method ◽  
Strain Energy ◽  
Vertical Force ◽  
Structural Stiffness ◽  
Contribution Ratio ◽  
The Finite Element Method ◽  
Vertical Stiffness ◽  
Strain Energy Method

The vertical stiffness of a tire is the ratio of the vertical force to the deflection; it can be expressed as the summation of the structural stiffness and air stiffness. However, the calculation of the structural stiffness is a challenging topic. This paper presents a new methodology for extracting the structural stiffness from the strain energy of a regular tire. In order to verify our proposed method, the vertical force-deflection results from the finite element method is compared with those from the strain energy method at zero air pressure. Also the results for an inflated tire are compared to calculate the structural stiffness. Finally, we calculated the contribution ratio of the tire components and used an alternative way of extracting the structural stiffness based on changing the Young’s modulus.

scholarly journals Thermal performance analysis and optimization design of dry type air core reactor with the double rain cover

2021 ◽  
pp. 67-67
Author(s):  
FaTing Yuan ◽  
Shouwei Yang ◽  
Shihong Qin ◽  
Kai Lv ◽  
Bo Tang ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Temperature Rise ◽  
Optimization Design ◽  
Orthogonal Experiment ◽  
Structural Parameters ◽  
Fluid Velocity ◽  
Optimization Method ◽  
Design Parameters ◽  
Air Core

In this paper, a fluid-thermal coupled finite element model is established according to the design parameters of dry type air core reactor. The detailed temperature distribution can be achieved, the maximum error coefficient of temperature rise is only 6% compared with the test results of prototype, and the accuracy of finite element calculate method is verified. Taking the equal height and heat flux design parameters of reactor as research object, the natural convection cooling performance of reactor with and without the rain cover is investigated. It can be found that the temperature rise of reactor is significantly increased when adding the rain cover, and the reasons are given by analyzing the fluid velocity distribution of air dcuts between the encapsulation coils. In order to reduce the temperature rise of the reactor with the rain cover, the optimization method based on the orthogonal experiment design and finite element method is proposed. The six factors of the double rain cover are given, which mainly affect the temperature rise of reactor, and the five levels are selected, the influence curve and contribution rate of each factor on the temperature rise of reactor are analyzed. The results show that the contribution ratio of the parameter H1, L1 and L2, are obviously higher than the parameter H2, L3 and ?, so the more attention should be paid in the design of double rain cover. Meanwhile, the optimal structural parameters of rain cover are given based on the influence curves, and the temperature rise is only 43.25?C. The results show that the optimization method can reduce the temperature rise of reactor significantly. In addition, the temperature distribution of inner encapsulations coils of reactor are basically the same, the current carrying capacity of coils can be fully utilized, which provides an important guidance for the optimization design of reactor.

Structural Design Optimization of Side/Rear Impact Guards Using a Coupled Genetic Algorithm Finite Element Method

2004 ◽  
Author(s):  
De-Shin Liu ◽  
Nan-Chun Lin ◽  
Chao-Chin Huang ◽  
Yin-Lee Meng
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Optimal Design ◽  
Computational Time ◽  
Design Parameters ◽  
Fe Model ◽  
Passenger Cars ◽  
Rear Impact ◽  
Structural Design Optimization ◽  
Energy Absorbing

Underride protective structure can reduce serious injures when passenger cars collide with the rear end or side of the heavy vehicle. This paper describes the use of Genetic Algorithm (GA) coupled with a dynamic, inelastic and large deformation finite element (FE) code LS-DYNA to search optimal design of the Side/Rear impact guards. In order to verify the accuracy of the FE model, the simulation results were compared with real experiments follow with the regulation ECE R73. The validated FE model then used to study the optimal design base on under running distance and total amount of energy absorbing capacity. The results from this study shown that this newly developed method not only can found multi-objective design parameters but also can reduce computational time significantly.

scholarly journals Numerical Modeling of Thermal Flows in Entrance Channels for Polymer Extrusion: A Parametric Study

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1256
Author(s):  
Medeu Amangeldi ◽  
Dongming Wei ◽  
Asma Perveen ◽  
Dichuan Zhang
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Temperature Distribution ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Flow Distribution ◽  
Element Model ◽  
Entrance Channel ◽  
Inlet Temperature ◽  
Flow Temperature

Flow distribution channels in extrusion dies are typically designed to assure uniform fluid velocity, pressure and temperature in the outlets. To ensure this uniformity, it is desirable to have the fluid melt to reach a steady state temperature in the entrance channel before entering the die body. This paper numerically investigates the temperature distribution of the fluid melt in the entrance channel. Analytical solutions of the velocity and finite element solutions of temperature distribution in Poiseuille flows of polypropylene melt with the Casson rheology model were derived and presented. In the velocity solution, the critical point that separates the core and the remaining parts in the flow was calculated by using the inlet flow rate and the yield stress in the Casson model. The velocity distribution was then substituted into the convective heat equation for temperature distribution simulations. A finite difference scheme was used to obtain the temperature distribution profiles along the flow direction in a parallel-plate, while the finite element model was used to model the flow temperature in circular tubes. The main outcome is the parametric analyses of the effect of various parameters such as radius, wall temperature, inlet temperature, and pressure drop to the optimal length of the channels required for the flow temperature to reach the steady state.

scholarly journals Calculations of Velocity and Temperature in a Polar Glacier using the Finite-Element Method

1979 ◽  
Vol 24 (90) ◽  
pp. 131-146 ◽  
Author(s):  
Roger LeB. Hooke ◽  
Charles F. Raymond ◽  
Richard L. Hotchkiss ◽  
Robert J. Gustafson
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Temperature Distribution ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Velocity Distribution ◽  
Vertical Velocity ◽  
Measured Temperature ◽  
Temperature Distributions ◽  
Flow Law

AbstractNumerical methods based on quadrilateral finite elements have been developed for calculating distributions of velocity and temperature in polar ice sheets in which horizontal gradients transverse to the flow direction are negligible. The calculation of the velocity field is based on a variational principle equivalent to the differential equations governing incompressible creeping flow. Glen’s flow law relating effective strain-rateε̇ and shear stressτbyε̇ = (τ/B)nis assumed, with the flow law parameterBvarying from element to element depending on temperature and structure. As boundary conditions, stress may be specified on part of the boundary, in practice usually the upper free surface, and velocity on the rest. For calculation of the steady-state temperature distribution we use Galerkin’s method to develop an integral condition from the differential equations. The calculation includes all contributions from vertical and horizontal conduction and advection and from internal heat generation. Imposed boundary conditions are the temperature distribution on the upper surface and the heat flux elsewhereFor certain simple geometries, the flow calculation has been tested against the analytical solution of Nye (1957), and the temperature calculation against analytical solutions of Robin (1955) and Budd (1969), with excellent results.The programs have been used to calculate velocity and temperature distributions in parts of the Barnes Ice Cap where extensive surface and bore-hole surveys provide information on actual values. The predicted velocities are in good agreement with measured velocities if the flow-law parameterBis assumed to decrease down-glacier from the divide to a point about 2 km above the equilibrium line, and then remain constant nearly to the margin. These variations are consistent with observed and inferred changes in fabric from fine ice with randomc-axis orientations to coarser ice with single- or multiple-maximum fabrics. In the wedge of fine-grained deformed superimposed ice at the margin,Bincreases again.Calculated and measured temperature distributions do not agree well if measured velocities and surface temperatures are used in the model. The measured temperature profiles apparently reflect a recent climatic warming which is not incorporated into the finite-element model. These profiles also appear to be adjusted to a vertical velocity distribution which is more consistent with that required for a steady-state profile than the present vertical velocity distribution.

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