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.

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.

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 Partial Slip Rolling Wheel-Rail Contact With an Oblique Rail Crack

2004 ◽  
Author(s):  
Yung-Chuan Chen ◽  
Jao-Hwa Kuang
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Friction Force ◽  
Element Model ◽  
Partial Slip ◽  
Contact Pressure Distribution ◽  
Tractive Force ◽  
Plastic Energy ◽  
Elastic Plastic ◽  
Pressure Distributions

The effect of rail surface crack on the wheel-rail contact pressure distribution under partial slip rolling was studied in this work. The elastic-plastic finite element model was employed for stress analyses. The numerical simulations were used to explore the effects of the contact distances and tractive force on the normal and tangential contact pressure distributions, tip plastic energy and critical wheel applied load. Contact elements were used to simulate the interaction between wheel and rail and crack surfaces. Numerical results indicate that the contact pressure distributions are significantly affected by the rail crack. Traditional contact theories are not available to describe the contact pressure distribution on the contact crack surfaces. Results also indicate that a higher friction force on the contact crack surfaces is observed for wheel subjected a larger tractive force. A larger crack surfaces friction force can reduce the sliding between crack surfaces and leads to a smaller tip plastic energy.

scholarly journals Effects of tire – pavement contact pressure distributions on the response of asphalt concrete pavements

1995 ◽  
Vol 22 (5) ◽  
pp. 849-860 ◽  
Author(s):  
Zhong Qi Yue ◽  
Otto J. Svec
Keyword(s):  
Pressure Distribution ◽  
Numerical Integration ◽  
Contact Pressure ◽  
Asphalt Concrete ◽  
Point Load ◽  
Asphalt Pavements ◽  
Numerical Verification ◽  
Concrete Pavements ◽  
Contact Pressure Distribution ◽  
Pressure Distributions

The paper presents the development of a computer program VIEM for the elastic analysis of multilayered elastic pavements under the action of arbitrary tire–pavement contact pressure distributions. The techniques adapted in VIEM primarily involves the use of a two-dimensional numerical integration to integrate point load solutions over the distributed pressure after discretizing the contact area into a finite number of triangular or quadrilateral elements. Values of contact pressure are inputted at the node points of discretized area. Numerical verification of VIEM indicates that numerical solution of high accuracy can be efficiently calculated for the elastic response of multilayered asphalt pavements. As a result, the determination of displacements and stresses (strains) can be achieved using a personal computer. With the use of VIEM, a theoretical investigation is further performed to illustrate the effects of tire–pavement contact pressure distributions on the response of asphalt concrete pavements. An in situ measured tire–pavement contact pressure distribution is utilized in the investigation. The response of asphalt concrete pavements due to the action of this measured contact pressure distribution is examined and compared with that due to the action of a uniform and circular contact pressure distribution by taking into account the influences of moduli and thicknesses of structural layers. The results of this investigation confirm theoretically a general consensus that details of the contact pressure distribution affect stresses and strains near the surface of the pavement, whereas the response in the lower layers depends mainly on the overall load. In particular, the contact pressure distributions have a significant effect on the horizontal tensile strains at the bottom of thin asphalt concrete layer which control the fatigue failure of asphalt pavements. Key words: tire–pavevment interaction, three-dimensional stress analysis, asphalt concrete pavements, numerical integration, multilayered elastic solids, point load solution.

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.

Two-Dimensional Contact Pressure Distribution of a Radial Tire

1990 ◽  
Vol 18 (2) ◽  
pp. 80-103 ◽  
Author(s):  
T. Akasaka ◽  
M. Katoh ◽  
S. Nihei ◽  
M. Hiraiwa
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Side Wall ◽  
Bending Moment ◽  
Two Dimensional ◽  
Contact Pressure Distribution ◽  
Friction Forces ◽  
Radial Tire ◽  
Pressure Distributions ◽  
Reaction Forces

Abstract Two-dimensional contact pressure distribution of a radial tire, statically compressed to a flat roadway, is analyzed using a rectangular contact patch. The tire structure is modeled by a spring-bedded ring belt comprised of a laminated-biased composite strip. The belt is supported by radial springs simulating the sidewall. The spring constant Kr was well defined previously by one of the authors. Deformation of the rectangular flat belt is obtained theoretically. The belt is subjected to inflation pressure, reaction forces transmitted from the spring bed of the tread rubber, and shearing force and bending moment along the belt boundaries brought from side-wall springs and the detached part of the ring belt. In-plane membrane forces, which are not uniform in the contact area, due to the friction forces acting between the tread surface and the roadway are also applied. The resulting contact pressure distributions in the circumferential direction are shown to be convex along the shoulder, but concave along the crown center line. This distribution agrees well with the experimental results.

Stress Analysis of the Multi-Layered System of a Truck Tire

2002 ◽  
Vol 30 (4) ◽  
pp. 240-264 ◽  
Author(s):  
X. Zhang ◽  
S. Rakheja ◽  
R. Ganesan
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Normal Load ◽  
Three Dimensional ◽  
Stress Fields ◽  
Layered System ◽  
Contact Pressure Distribution ◽  
Pressure Distributions ◽  
Truck Tire ◽  
Stress And Deformation

Abstract In this paper, a nonlinear finite element tire model is developed as an effective fast modeling approach to analyze the stress fields within a loaded tire structure, with the contact patch geometry and contact pressure distribution in the tire-road interface as functions of the normal load and the inflation pressure. The model considers the geometry and orientations of the cords in individual layers and the stacking sequence of different layers in the multi-layered system to predict the interply interactions in the belts and carcass layers. The study incorporates nearly incompressible property of the tread rubber block and anisotropic material properties of the layers. The analysis is performed using ANSYS software, and the results are presented to describe the influence of the normal load on the various stress fields and contact pressure distributions. The computed footprint geometry is qualitatively compared with the measured data to examine the validity of the model. It is concluded that the proposed model can provide reliable predictions about the three-dimensional stress and deformation fields in the multi-layered system and the contact pressure distribution in the tire-road interface.

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