Finite element analysis of the ovine hip: Development, results and comparison with the human hip

2012 ◽  
Vol 25 (04) ◽  
pp. 301-306 ◽  
Author(s):  
J. Jalali ◽  
F. Schmidutz ◽  
C. Schröder ◽  
M. Woiczinski ◽  
J. Maierl ◽  
...  
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Pelvic Bone ◽  
Acetabular Cartilage ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Average Value ◽  
Femoral Cartilage ◽  
Acetabular Side

SummaryObjectives: The ovine hip is often used as an experimental research model to simulate the human hip. However, little is known about the contact pressures on the femoral and acetabular cartilage in the ovine hip, and if those are representative for the human hip.Methods: A model of the ovine hip, including the pelvis, femur, acetabular cartilage, femoral cartilage and ligamentum transversum, was built using computed tomography and microcomputed tomography. Using the finite element method, the peak forces were analysed during simulated walking.Results: The evaluation revealed that the contact pressure distribution on the femoral cartilage is horseshoe-shaped and reaches a maximum value of approximately 6 MPa. The maximum contact pressure is located on the dorsal acetabular side and is predominantly aligned in the cranial-to-caudal direction. The surface stresses acting on the pelvic bone reach an average value of approximately 2 MPa.Conclusions: The contact pressure distribution, magnitude, and the mean surface stress in the ovine hip are similar to those described in the current literature for the human hip. This suggests that in terms of load distribution, the ovine hip is well suited for the preclinical testing of medical devices designed for the human hip.

Analysis of Contact Pressure Distribution on 3-Bolt Self-Energized Connector Seals

2009 ◽  
Author(s):  
Rajeev Madazhy ◽  
Sheril Mathews ◽  
Erik Howard
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Maximum Pressure ◽  
Operating Pressure ◽  
Seal Ring ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Novel Design

A novel design using 3 bolts for a self-energized seal connector is proposed for quick assembly applications. Contact pressure distribution on the surface of the seal ring during initial bolt-up and subsequent operating pressure is analyzed for 3″ and 10″ connectors using Finite Element Analysis. FEA is performed on a 3″ and 10″ ANSI RF flange assembly and contact pressure distribution on the RF gasket is compared with the tapered seal ring assemblies. Hydrostatic tests are carried out for the tapered seal and ANSI bolted connectors to evaluate maximum pressure at which leak occurs for both size assemblies.

Elastic-Plastic Finite Element Analysis of Indented Layered Media

1989 ◽  
Vol 111 (3) ◽  
pp. 430-439 ◽  
Author(s):  
K. Komvopoulos
Keyword(s):  
Finite Element ◽  
Plastic Zone ◽  
Contact Pressure ◽  
Critical Parameters ◽  
The Finite Element Method ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Substrate Properties ◽  
Layered Half Space

The elastic-plastic contact problem of a layered half-space indented by a rigid surface is solved with the finite element method. The case of a layer stiffer and harder than the substrate is analyzed and solutions for the contact pressure, subsurface stresses and strains, and location, shape, and growth of the plastic zone are presented for various layer thicknesses and indentation depths. Finite element results for a halfspace having the substrate properties are also given for comparison purposes. Differences between the elastic and elastic-plastic solutions are discussed and the significance of critical parameters such as the layer thickness, mechanical properties of layer and substrate materials, indentation depth, and interfacial friction on the threshold of plasticity, contact pressure distribution, and growth of the plastic zone are examined. Additionally, the mechanisms of layer decohesion and subsurface crack initiation are interpreted in light of the results obtained in this study.

Analysis on the Contact Pressure Distribution of Chemical Mechanical Polishing by the Bionic Polishing Pad with Phyllotactic Pattern

2011 ◽  
Vol 215 ◽  
pp. 217-222 ◽  
Author(s):  
Y.S. Lv ◽  
Nan Li ◽  
Jun Wang ◽  
Tian Zhang ◽  
Min Duan ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Boundary Edge ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Polishing Pad

In order to make the contact pressure distribution of polishing wafer surface more uniform during chemical mechanical polishing (CMP), a kind of the bionic polishing pad with sunflower seed pattern has been designed based on phyllotaxis theory, and the contact model and boundary condition of CMP have been established. Using finite element analysis, the contact pressure distributions between the polishing pad and wafer have been obtained when polishing silicon wafer and the effects of the phyllotactic parameter of polishing pad on the contact pressure distribution are found. The results show that the uniformity of the contact pressure distribution can be improved and the singularity of the contact pressure in the boundary edge of polished wafer can be decreased when the reasonable phyllotactic parameters are selected.

Hot judder behavior in multidisc clutches

2016 ◽  
Vol 231 (1) ◽  
pp. 136-146 ◽  
Author(s):  
Biao Ma ◽  
Likun Yang ◽  
Heyan Li ◽  
Nan Lan
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Degrees Of Freedom ◽  
Frictional Heat ◽  
Contact Pressure Distribution ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Engagement Process ◽  
The Coefficient Of Friction ◽  
Interface Contact

This paper presents an investigation of the hot judder phenomenon of multidisc clutches, which takes place during the engagement process. Depending on the results of finite element analysis, a pressure distribution function is defined and a contact pressure equation is established to demonstrate the non-uniformity of the contact pressure distribution on the friction interfaces due to frictional heat. The relationship between the coefficient of friction and the temperature is analyzed. A 4 degrees of freedom power-train model is developed to evaluate the clutch judder behavior. The paper indicates that the clutch judder is influenced by the non-uniformity of the interface contact pressure distribution, which is excited by frictionally induced thermal load. The non-uniform contact pressure distributions along the radial direction have a slight influence on the clutch judder, while the uneven contact pressure distributions along the circumference contribute to the judder substantially. Furthermore, the results in this work can be used to study the operation instability and the thermal failure of clutches.

A Method for Characterizing Running-In of Sliding Contacts

2016 ◽  
Vol 681 ◽  
pp. 228-233
Author(s):  
R. Ismail ◽  
M. Tauviqirrahman ◽  
J. Jamari ◽  
D.J. Schipper
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Distribution ◽  
Sliding Contact ◽  
Wear Depth ◽  
Contact Pressure Distribution ◽  
Sliding Contacts ◽  
Element Analysis ◽  
Element Simulation ◽  
Proposed Model

Although in terms of conservation wear is undesirable, however, running-in wear is encouraged rather than avoided. Running-in is rather complex and most of the studies related to the change in micro-geometry have been conducted statistically. The purpose of this study was to characterize the running-in of sliding contacts using finite element analysis based on measured micro-geometries. The developed model combines the finite element simulation, Archard’s wear equation and updated geometry to calculate the contact pressure distribution and wear depth. Results show that the proposed model is able to predict the running-in phase of sliding contact system.

A Finite Element Tire Model

1983 ◽  
Vol 11 (1) ◽  
pp. 50-63 ◽  
Author(s):  
J. T. Tielking
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Shell Of Revolution ◽  
Comprehensive Model ◽  
Tire Model ◽  
Contact Pressure Distribution ◽  
Design Variables ◽  
Nonlinear Shell ◽  
Basic Characteristics

Abstract A finite element tire model, based on nonlinear shell of revolution elements, has been developed to investigate tire-pavement interaction. The basic characteristics of this relatively comprehensive model are reviewed here, with attention focused on its ability to calculate the effect of tire design variables on tire performance data. A four-ply bias tire is used to show the ability of the model to predict the different effects that nylon and polyester cords have on tire deformation, contact pressure distribution, and traction.

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