An Analytical and Experimental Study of a Tire Rolling Over a Stepped Obstacle at Low Velocity

1994 ◽  
Vol 22 (3) ◽  
pp. 162-181 ◽  
Author(s):  
C. W. Mousseau ◽  
S. K. Clark
Keyword(s):  
Large Deformation ◽  
Contact Problems ◽  
Force Measurements ◽  
Inflation Pressure ◽  
Low Velocity ◽  
Finite Element Program ◽  
Beam Elements ◽  
Radial Stiffness ◽  
Static Contact ◽  
Element Program

Abstract The ring on elastic foundation (REF) model has been used as a pneumatic tire analog for many types of two-dimensional contact problems. This paper investigates the suitability of the model to reproduce hub forces during large deformation, quasi-static contact. Two types of tire contact problems are considered in this paper. The first problem is a tire deforming against a flat plate, and the second is a tire rolling over a 50 mm step. The REF model is implemented in a nonlinear, finite element program with elements that accommodate large deformation and contact. Experimental hub force measurements verify the simulation results. This paper shows that the best match with experimental data is accomplished with a model that consists entirely of beam elements and includes a softening foundation. Also, it shows that the hub force is strongly dependent on the radial stiffness of the foundation and the inflation pressure.

scholarly journals Comparison of stress induced in mandible around an implant-supported overdenture with locator attachment and telescopic crowns – a finite element analysis

2020 ◽  
Author(s):  
Meer Rownaq Ali Abbasi ◽  
Dileep Nag Vinnakota ◽  
Vijaya Sankar V ◽  
Rekhalakshmi Kamatham
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Clinical Performance ◽  
Compressive Load ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Finite Element Program ◽  
Static Contact ◽  
Element Program ◽  
Von Mises

Introduction. One of the principle factors for the success of implant supported/retained overdentures (IOs) is the manner in which the stresses are transferred to the surrounding bone. Hence, the aim of the present study is to compare the stress induced in the mandible around IOs, using two different attachment systems, locator and telescopic. Methods. 3D finite element models were prepared using Pro/ENGINEER or PTC Creo to simulate 4 clinical situations: IOs using two different attachment systems, locator and telescopic, with and without splinting. A vertical compressive load of 35N was directed toward the central fossa in the molar region of each overdenture. Non-linear static contact analysis was carried out to determine the stress distribution in various components of IOs. Then, the models were analyzed by a finite element program ABAQUS, and displayed using Von Mises stress patterns. Results. The contact stress values developed on the implant and attachment components were lower with locator attachment, in both splinted and non-splinted models. On the other hand, the stress distribution to the cortical bone was more with non-splinted/splinted locator attachments (3.73/4.12 Mega Pascals) when compared to the non-splinted/splinted telescopic attachments (2.66/3.7 Mega Pascals). The stresses in all the components of overdenture were greater with the splinted model compared to non-splinted, in both the attachment systems.  Conclusion. The locator attachment might demonstrate superior clinical performance, as the stresses on implant and attachment components were less compared to telescopic. Non-splinted model showed better results in both the attachment types.

scholarly journals Static analysis of transmission tower beam structure

2018 ◽  
Vol 244 ◽  
pp. 01011 ◽  
Author(s):  
Lenka Jakubovičová ◽  
Alžbeta Sapietová ◽  
Jan Moravec
Keyword(s):  
Static Analysis ◽  
Bending Moment ◽  
Loss Of Stability ◽  
Transmission Tower ◽  
Beam Structure ◽  
Finite Element Program ◽  
Beam Elements ◽  
The Earth ◽  
Element Program ◽  
Ansys Workbench

The main topic of this paper is a static analysis of transmission tower beam structure fixed to the earth. It contains facts necessary for a need to create and apply tower beam structures. Beam elements were used to design a model and a static analysis was performed in finite element program Ansys Workbench. Three types of analyses were applied. The modal analysis was applied to verify the model compatibility. The static analysis was applied to find maximal deformations and the bending moment caused by overhead conductors and self-weight. Eigenvalue buckling was applied to state a loss of stability. Finally, stability and suitability of the whole construction was considered.

Finite Element Simulations of Free Surface Flows With Surface Tension in Complex Geometries

2002 ◽  
Vol 124 (3) ◽  
pp. 584-594 ◽  
Author(s):  
Gang Wang
Keyword(s):  
Surface Tension ◽  
Finite Element ◽  
Free Surface ◽  
Surface Force ◽  
Free Surface Flows ◽  
Complex Geometries ◽  
Finite Element Program ◽  
Surface Flows ◽  
Static Contact ◽  
Element Program

The finite-element program, ANSYS/FLOTRAN, has been enhanced at Release 5.7 to predict free surface flows with surface tension in complex geometries. The two-dimensional incompressible Navier-Stokes and energy equations are solved in both Cartesian and axisymmetric coordinate systems. At Release 5.6, the free surface capabilities have been incorporated into ANSYS/FLOTRAN using the CLEAR-VOF algorithm. The main contribution of this work is to implement a surface tension model into ANSYS/FLOTRAN to study free surface flows with surface tension in complex geometries. Both normal and tangential components of surface tension forces are modeled at the interface through a continuum surface force (CSF) model. This new algorithm is first validated with two model problems: a droplet in equilibrium and an oscillating droplet. For the first problem, the computed pressure value is compared with the theoretical value, whereas for the second problem, the oscillation frequency is compared with both the analytical solution and experimental data. The computer program is then applied to thermocapillary flows in two types of trapezoidal cavities to investigate the interesting flow and heat transfer characteristics. Systematic calculations are performed to study the influence of Marangoni number, capillary number and static contact angle on Marangoni convection.

Large Deformation Analysis of Structures Enclosing Air Cavities

2006 ◽  
Author(s):  
Hassan N. Bayoumi
Keyword(s):  
Large Deformation ◽  
Ideal Gas ◽  
Deformation Analysis ◽  
User Friendliness ◽  
Finite Element Program ◽  
Practical Applications ◽  
Element Program ◽  
External Forces ◽  
Air Cavities ◽  
The Ideal

In this paper, a method to analyze structures that enclose cavities filled with an ideal gas such as air is presented. The method has been implemented in a commercial nonlinear finite element program. The power of this method is in its simplicity and user friendliness. The change of pressure in the cavity resulting from the large deformation of the structure due to the application of external forces is automatically evaluated according to the ideal gas equations. The volume of the cavity is continuously updated and used to determine the changes in the cavity pressure. The method has been extended to model cavities partially filled with incompressible fluids and air. The method has also been successfully used in coupled thermal-stress problems. Several applications that use this method are presented. The applications range from simple problems used to validate the accuracy of the method against other techniques in the literature to real practical applications. Applications presented include fluid containers, airsprings and rubber seals.

Dynamic Impact Simulation Study of Tubeless Pneumatic Tires

2016 ◽  
Author(s):  
Floyd Linayao ◽  
Raymond K. Yee
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Parameters ◽  
Inflation Pressure ◽  
Element Analysis ◽  
Finite Element Program ◽  
First Case ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Three Dimensional Finite Element

Traditionally speaking, prototype tires are designed, and then tested on an experimental basis to evaluate performance. Using finite element analysis instead allows tire design parameters to be modified at will and underperforming architectures to be ruled out. This paper characterizes the dynamic response of a tubeless pneumatic vehicle tire as it is exposed to sudden impact and determines conditions under which failure would occur. Three cases were studied using a 175SR14 passenger tire, since passenger tires are most commonly used and impacts are more substantial on smaller tires. ABAQUS finite element program was used to perform nonlinear transient dynamic three-dimensional finite element analyses for three commonly tire encountered conditions. The first case, direct curb impact, determined that a safe inflation pressure range for tire velocities exists between 10 and 60 km per hour (kph). The second case, angled curb impact, found a smaller range of 10 to 40kph. The third case, impact with a pothole, found that at low inflation pressures, less stress is produced at higher velocities; increasing inflation pressure results in a transition point, causing larger stresses to be produced at higher velocities. From these analyses, several conclusions are drawn: inflation pressures below 100KPa do not produce a useful relationship between tire velocity and stress; thicker sidewalls help shield the tire from impact failure; and it is better for the tire to accelerate past a pothole in the 30 to 70kph range.

Finite Element Study of Pressure Wave Attenuation by Reactor Fuel Subassemblies

1975 ◽  
Vol 97 (3) ◽  
pp. 172-177 ◽  
Author(s):  
T. Belytschko ◽  
J. M. Kennedy
Keyword(s):  
Finite Element ◽  
Wave Attenuation ◽  
Reactor Core ◽  
Finite Element Program ◽  
Beam Elements ◽  
Dynamic Finite Element ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Complex Boundary ◽  
Surrounding Fluid

The attenuation of pressure waves by the subassembly walls in a reactor core was studied by a two dimensional, finite element program. For these purposes, a hydro-dynamic finite element was incorporated in an existing dynamic structural program. The resulting program has the advantage that complex boundary conditions and the interaction of structural and fluid elements are handled in a straightforward manner. The program was used to model a section of the hexcan and the surrounding fluid; the hexcan was modelled by beam elements. It is shown that the hexcan walls attenuate pressure peaks by about 33 percent in the adjacent subassembly. Thus the subassembly walls may play an important role in confining the effects of local accidents.

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