Energy Loss in an Analytical Membrane Tire Model

1977 ◽  
Vol 5 (3) ◽  
pp. 136-151 ◽  
Author(s):  
J. T. Tielking ◽  
R. A. Schapery
Keyword(s):  
Power Loss ◽  
Load Transfer ◽  
Flat Surface ◽  
Transfer Functions ◽  
Rolling Resistance ◽  
Elastic Response ◽  
Tire Model ◽  
The Finite Element Method ◽  
Low Loss ◽  
Static Loads

Abstract Energy dissipation is calculated from the contact deformation of a rolling toroidal membrane tire model. The method of dissipation analysis developed here can be used with other structural representations, including those based on the finite element method. The membrane tire model is inflated, loaded, and rolling on a frictionless, flat surface. The membrane material is assumed to be isotropic and neohookean under static loads and to exhibit a low loss tangent. The assumption of a low loss material permits viscoelastic power loss to be calculated from load transfer functions derived from the elastic response of the tire model. The power loss calculation is used to predict rolling resistance and contact patch shift.

Tread Depth Effects on Tire Rolling Resistance

2001 ◽  
Vol 29 (3) ◽  
pp. 134-154 ◽  
Author(s):  
J. R. Luchini ◽  
M. M. Motil ◽  
W. V. Mars
Keyword(s):  
Finite Element Analysis ◽  
Common Knowledge ◽  
Rolling Resistance ◽  
Test Method ◽  
Tire Model ◽  
Element Analysis ◽  
Truck Tires ◽  
The Finite Element Analysis ◽  
Equilibrium Test ◽  
Depth Effects

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

Biomechanical Behavior of All-Ceramic Crowns with Variable Thicknesses of Zirconia Frameworks

2016 ◽  
Vol 835 ◽  
pp. 97-102
Author(s):  
Liliana Porojan ◽  
Florin Topală ◽  
Sorin Porojan
Keyword(s):  
Mechanical Behavior ◽  
Equivalent Stress ◽  
The Finite Element Method ◽  
Static Loads ◽  
Biomechanical Behavior ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Von Mises Equivalent Stress ◽  
Von Mises ◽  
Posterior Restorations

Zirconia is an extremely successful material for prosthetic restorations, offering attractive mechanical and optical properties. It offers several advantages for posterior restorations because it can withstand physiological posterior forces. The aim of the study was to achieve the influence of zirconia framework thickness on the mechanical behavior of all-ceramic crowns using numerical simulation. For the study a premolar was chosen in order to simulate the mechanical behavior in the components of all-ceramic crowns and teeth structures regarding to the zirconia framework thickness. Maximal Von Mises equivalent stress values were recorded in teeth and restorations. Due to the registered maximal stress values it can be concluded that it is indicated to achieve frameworks of at least 0.5 mm thickness in the premolar area. Regarding stress distribution concentration were observed in the veneer around the contact areas with the antagonists, in the framework under the functional cusp and in the oral part overall and in dentin around and under the marginal line, also oral. The biomechanical behavior of all ceramic crowns under static loads can be investigated by the finite element method.

The Numerical Simulation of Effective Elastic Response for WC-Co Cemented Carbide

2015 ◽  
Vol 1096 ◽  
pp. 417-421
Author(s):  
Pei Luan Li ◽  
Zi Qian Huang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Theoretical Model ◽  
Material Properties ◽  
Cemented Carbide ◽  
Elastic Response ◽  
The Finite Element Method ◽  
Simulation Results ◽  
Element Method

By the use of finite element method, this paper predicts the effects of the shapes of reinforcements with different ductility (Co) on the effective elastic response for WC-Co cemented carbide. This paper conducts a comparative study on the material properties obtained through theoretical model, numerical simulation and experimental observations. Simulation results indicate that the finite element method is more sophisticated than the theoretical prediction.

Dynamic Response of Squeeze Film Dampers Operating With Bubbly Mixtures

2002 ◽  
Author(s):  
Luis San Andre´s ◽  
Oscar C. De Santiago
Keyword(s):  
Load Transfer ◽  
Transfer Functions ◽  
Dynamic Performance ◽  
Air Entrainment ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Performance Impact ◽  
Air Content ◽  
Squeeze Film Dampers ◽  
Oil Mixtures

Squeeze film dampers (SFDs) aid to attenuate vibrations in compressors and turbines while traversing critical speeds. In actual applications, gas ingestion from the environment may lead to the formation of a foamy lubricant that degrades the rotor/bearing system dynamic performance. Impact and imbalance response tests conducted on a rigid rotor supported on SFDs, and aimed to emulate the pervasive effect of air ingestion into the damper film lands, are reported. Two types of squeeze film damper support the test rotor, one is a conventional cylindrical design with a squirrel cage type elastic support, and the other is a compact four-pad damper with integral wire EDM elastic supports. Both dampers have identical diameter and radial clearance. Controlled (air in oil) mixtures ranging from pure oil to all air conditions are supplied to the SFDs, and measurements of the transient rotor response to calibrated impact loads are conducted. System damping coefficients, identified from acceleration/load transfer functions, decrease steadily as the air content in the mixture increases. However, measurements of the rotor synchronous imbalance response conducted with a lubricant bubbly mixture (50% air volume) show little difference with test results obtained with pure lubricant supplied to the dampers. The experimental results show that air entrainment is process and device dependent, and that small amounts of lubricant enable the effective action of SFDs when the rotor traverses a critical speed.

On Rolling Resistance in Gear Transmission

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
S. S. Ghosh ◽  
G. Chakraborty
Keyword(s):  
Experimental Data ◽  
Friction Force ◽  
Contact Force ◽  
Power Loss ◽  
Degrees Of Freedom ◽  
Rolling Resistance ◽  
Spur Gear ◽  
Gear Transmission ◽  
Gear Pair ◽  
Six Degrees Of Freedom

The effect of rolling resistance on the power loss during gear transmission has been studied. The resistance has been modeled by a lateral shift of the line of action of the contact force. The effect of this shift on the equivalent friction force has been predicted with the help of a six degrees of freedom (DOF) model of a spur gear pair. The predicted results agree closely with the experimental data available in literature.

Reversible Realization of 4-Bit Vedic Multiplier Circuit with Optimized Performance Parameters

2019 ◽  
Vol 17 (10) ◽  
pp. 826-831
Author(s):  
Vandana Shukla ◽  
O. P. Singh ◽  
G. R. Mishra ◽  
R. K. Tiwari
Keyword(s):  
Low Power ◽  
Power Loss ◽  
High Speed ◽  
Digital Circuit ◽  
Performance Parameters ◽  
Low Loss ◽  
Vital Part ◽  
Multiplication Process ◽  
Vedic Multiplier ◽  
Multiplier Circuit

Low power high speed calculating devices are foremost requirement of this era. Moreover, multiplication is considered as the most vital part of any calculating system. Multiplication process is generally considered as the speed limiting process as it requires more time as compared to other basic arithmetic calculations. So, here we focus on multiplication calculation using vedic method. Moreover, Reversible realization of any digital circuit improves the performance of the system by reducing the power loss from it. Here, the concept of vedic multiplication and Reversible approach are combined to propose a 4-bit multiplier circuit with optimized performance parameters. Proposed design is also analyzed and compared with existing designs. This approach may be employed to propose other low loss devices.

Suppression of Edge Delamination Through Meso-Scale Structuring

Materials ◽  
2005 ◽  
Author(s):  
J. N. Baucom ◽  
M. A. Qidwai ◽  
W. R. Pogue ◽  
J. P. Thomas
Keyword(s):  
Load Transfer ◽  
Fiber Reinforced Polymer ◽  
The Finite Element Method ◽  
Interlaminar Stresses ◽  
New Class ◽  
Tile Size ◽  
Reinforced Polymer ◽  
Edge Delamination ◽  
Design Freedom ◽  
Free Edges

We are developing a new class of fiber-reinforced polymer composite materials to facilitate imbedding multifunctional features and devices in material systems, and to manage interlaminar stresses at free edges and cut-outs. The idea is centered on introducing one more level of design space by composing plies with individual tiles possessing the same degrees of design freedom that are associated with individual plies. In this work, we have focused on tiling schemes that will allow blending of laminates (lay-ups), where a lay-up suitable for suppressing interlaminar stresses could be placed at necessary locations whereas another lay-up could be used for the main objective. This results in the introduction of matrix-rich tile-to-tile interface pockets in the blending region. Preliminary mechanical testing shows that uniaxially reinforced tiled composites attain stiffness levels near those of their traditional counterparts, yet with a potential degradation of strength. We used the finite element method to investigate the effects of resin-rich pocket size, the use of supporting continuous layers, tile size, and tile overlapping (interface stacking) schemes on stress distribution around interfaces in uniaxially reinforced tiled composites, with the aim to identify parameters controlling overall strength. We discovered that alignment of the resin-rich pockets through the thickness exacerbates stress-concentration and that outer continuous layers on the composite may help in better load transfer. As a first step in the application of this technique for the suppression of delamination at the free edges of holes in laminates, a bilaminate material was modeled, and the concept was shown to be effective in the suppression of edge delamination.

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