Modeling the Dynamic Frictional Contact of Tires Using an Explicit Finite Element Code

2005 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Michael J. Leamy
Keyword(s):  
Finite Element ◽  
Frictional Contact ◽  
Time Integration ◽  
Friction Model ◽  
Finite Element Code ◽  
Normal Contact ◽  
Explicit Finite Element ◽  
Beam Elements ◽  
Coulomb Friction Model ◽  
Stiffness And Damping

A time-accurate explicit time-integration finite element code is used to simulate the dynamic response of tires including tire/pavement and tire/rim frictional contact. Eight-node brick elements, which do not exhibit locking or spurious modes, are used to model the tire’s rubber. Those elements enable use of one element through the thickness for modeling the tire. The bead, tread and ply are modeled using truss or beam elements along the tire circumference and meridian directions with appropriate stiffness and damping properties. The tire wheel is modeled as a rigid cylinder. Normal contact between the tire and the wheel and between the tire and the pavement is modeled using the penalty technique. Friction is modeled using an asperity-based approximate Coulomb friction model.

Asperity Spring Friction Model With Application to Belt-Drives

2003 ◽  
Author(s):  
Tamer M. Wasfy
Keyword(s):  
Finite Element ◽  
Coulomb Friction ◽  
Friction Model ◽  
Belt Drive ◽  
Finite Element Code ◽  
Time Step ◽  
Stick Slip ◽  
Normal Contact ◽  
Belt Drives ◽  
Coulomb Friction Model

An asperity spring friction model that uses a variable anchor point spring along with a velocity dependent force is presented. The model is incorporated in an explicit timeintegration finite element code. The friction model is used along with a penalty-based normal contact model to simulate the dynamic response of a two-pulley belt-drive system. It is shown that the present friction model accurately captures the stick-slip behavior between the belt and the pulleys using a much larger time-step than a pure velocity-dependent approximate Coulomb friction model.

Dynamic Modeling of Synchronous Belt-Drives Using an Explicit Finite Element Code

2005 ◽  
Author(s):  
Tamer M. Wasfy ◽  
Michael J. Leamy
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Fixed Number ◽  
Friction Model ◽  
Rigid Bodies ◽  
Finite Element Code ◽  
Tooth Contact ◽  
Friction Forces ◽  
Normal Contact ◽  
Explicit Finite Element

A time-accurate explicit time-integration finite element code is used to simulate the dynamic response of synchronous belts-drives. The belt is modeled using beam or truss elements. The sprockets are modeled as cylindrical rigid bodies. Normal contact between the belt and a sprocket is modeled using the penalty technique and friction is modeled using an asperity-based approximate Coulomb friction model. The belt teeth/grooves are assumed to be located at the belt nodes (every fixed number of belt nodes). The nodes in-between teeth are subjected to the normal contact and tangential friction forces. The belt and sprocket teeth are assumed to be trapezoidal. The equivalent belt-sprocket tooth stiffness and damping coefficients in the normal tooth contact direction are used to calculate a normal tooth contact force at the belt teeth nodes. The tooth contact model also includes the effect of the tooth engagement tolerance. For validation purposes, a two-sprocket drive is modeled and a comparison is made between tooth loads predicted by the finite element model and experimental data available in the literature. Reasonable agreement between the simulation and experimental results is found of the drive’s tooth loads. Also, the dynamic response of a hybrid sprocket – flat pulley belt-drive is studied.

A Finite Element Study on Contact Pressure Distribution in Draw-Bend Friction Test and Its Effect on Friction Measurement

2005 ◽  
Author(s):  
Young Suk Kim ◽  
Don R. Metzger ◽  
Mukesh K. Jain
Keyword(s):  
Finite Element ◽  
Coulomb Friction ◽  
Friction Model ◽  
Friction Test ◽  
Friction Measurement ◽  
Explicit Finite Element ◽  
Constant Friction ◽  
Friction Models ◽  
Bend Tests ◽  
Coulomb Friction Model

Various experimental and numerical works have shown the existence of pressure peaks at the contact interface of draw-bend tests. From this observation, a need has been raised for the re-examination of the methodology to calculate the friction coefficient from the draw-bend friction test. In this paper, the draw-bend friction tests have been simulated by the explicit finite element method. By using 3D finite element models and local axis system, the existence of pressure peaks was confirmed. A non-constant friction model (Stribeck friction model), which is more realistic for sheet metal forming than a constant friction model (Coulomb friction model), was implemented into the finite element code. Simulations were performed with constant and non-constant friction models. From the comparisons, the effect of existence of pressure peaks on the friction measurement was evaluated.

A Simplified Finite Element for Added Mass and Inertial Coupling in Arrays of Cylinders

1985 ◽  
Vol 107 (2) ◽  
pp. 118-125 ◽  
Author(s):  
R. E. Harris ◽  
M. A. Dokainish ◽  
D. S. Weaver
Keyword(s):  
Finite Element ◽  
Time Integration ◽  
Element Model ◽  
Added Mass ◽  
Cylindrical Structures ◽  
Beam Elements ◽  
Inertial Coupling ◽  
Fundamental Frequencies ◽  
Tube Bundles ◽  
Primary Advantage

A simplified finite element has been developed for modeling the added mass and inertial coupling arising when clusters of cylinders vibrate in a quiescent fluid. The element, which is based on two-dimensional potential flow theory, directly couples two adjacent beam elements representing portions of the adjacent cylindrical structures. The primary advantage of this approach over existing methods is that it does not require the discretization of the surrounding fluid and, therefore, is computationally much more efficient. The fundamental frequencies of tube bundles of various pitch ratios have been predicted using this method and compared with experimental data. Generally, the agreement is good, especially for the bandwidth of fluid coupled natural frequencies. The transient response of tube bundles is also examined using time integration of the finite element model. The beating phenomenon and time decay characteristics exhibited by the experimental bundles under single-tube excitation are well predicted and valuable insights are gained into the measurement of damping in tube bundles.

Finite Element Modeling of Unidirectional Non-Crimp Fabric for Manufacturing of Composites with Embedded Cabling

2013 ◽  
Vol 554-557 ◽  
pp. 484-491 ◽  
Author(s):  
Alexander S. Petrov ◽  
James A. Sherwood ◽  
Konstantine A. Fetfatsidis ◽  
Cynthia J. Mitchell
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Explicit Finite Element ◽  
Shell Elements ◽  
Beam Elements ◽  
Hybrid Finite Element ◽  
International Benchmarking ◽  
Unidirectional Glass ◽  
Forming Simulations

A hybrid finite element discrete mesoscopic approach is used to model the forming of composite parts using a unidirectional glass prepreg non-crimp fabric (NCF). The tensile behavior of the fabric is represented using 1-D beam elements, and the shearing behavior is captured using 2-D shell elements into an ABAQUS/Explicit finite element model via a user-defined material subroutine. The forming of a hemisphere is simulated using a finite element model of the fabric, and the results are compared to a thermostamped part as a demonstration of the capabilities of the used methodology. Forming simulations using a double-dome geometry, which has been used in an international benchmarking program, were then performed with the validated finite element model to explore the ability of the unidirectional fabric to accommodate the presence of interlaminate cabling.

Development of a Design Sensitivity Analysis Technique for Explicit Finite Element Software With Applications in Crashworthiness

2000 ◽  
Author(s):  
Douglas W. Stillman
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Time Integration ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Element Analysis ◽  
Automotive Safety ◽  
Explicit Finite Element ◽  
Finite Element Software ◽  
Analysis Technique

Abstract Design Sensitivity Analysis (DSA) is a widely used technique in many areas of finite element analysis, but one that hasn’t yet become available for industrial problems in crashworthiness and automotive safety. In the following effort, an implementation of DSA in the automotive safety simulation program, Radioss, is described. Radioss is a non-linear structures program using an explicit time integration method. A full set of DSA equations are developed and integrated into Radioss so that the design sensitivities can be computed directly and accurately as a result of a single crashworthiness simulation. Some validation results are included. The resulting methodology promises to be an extremely useful tool for engineers involved in the design of safety and crashworthiness of automobiles.

Numerical Simulation of Galloping for Iced Quad-Bundled Conductor

2014 ◽  
Vol 1025-1026 ◽  
pp. 955-958 ◽  
Author(s):  
Jun Jie Shi ◽  
Ya Nan Li ◽  
Li Qin
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Simulation Analysis ◽  
Time Integration ◽  
Vertical Vibration ◽  
Analysis Model ◽  
Element Analysis ◽  
Beam Elements ◽  
Time Integration Method ◽  
Wake Interference

The theoretical study of galloping can effectively promote anti-galloping techniques. Cable element is utilized to imitate the bundled conductor, and beam elements are used to simulated the spacers, established galloping finite element analysis model which can consider sub-conductors wake interference. The finite element equation was solved by time integration method and the calculation program was compiled by MATLAB. Through numerical simulation analysis, compared the dancing in the case of considering the effect of the sub-conductor wake and ignoring the effect of the sub-conductor wake. The results showed that considering the effect of the wake on aerodynamic loads has a greater vertical vibration amplitude. This method can provide reference for the study of prevention technology on dancing.

Study on the collapse of tapered tubes subjected to oblique loads

2008 ◽  
Vol 222 (11) ◽  
pp. 2025-2039 ◽  
Author(s):  
P Hosseini-Tehrani ◽  
S Pirmohammad ◽  
M Golmohammadi
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Numerical Models ◽  
Point Of View ◽  
Finite Element Code ◽  
Energy Absorber ◽  
Explicit Finite Element ◽  
Bending Deformation ◽  
Oblique Loading

In this work, several antisymmetric tapered tubes with an inner stiffener under axial and oblique loading are studied and optimum dimensions of the tapered tube are derived from a crashworthiness point of view. The importance of detecting these dimensions is optimizing the weight while the crashworthiness of tube is not damaged. By using an internal stiffener, crashworthiness is improved against oblique loads, and the sensitivity of tubes with respect to oblique loads and bending deformation is diminished. The numerical models have been developed using the explicit finite element code LS-DYNA. The crashworthiness of the optimized tapered tube is compared with that of an octagonal-cross-section tube which is known as the best energy absorber model in the literature. It is shown that an optimized tapered tube has an average of 29.3 per cent less crushing displacement in comparison with octagonal-section tube when both tubes have the same weights and the same peaks of crushing load. Finally, the orientation of loading is changed and the best orientation is proposed.

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