scholarly journals Molecular Dynamics Study of Contact Mechanics: Contact Area and Interfacial Separation from Small to Full Contact

2008 ◽  
Vol 100 (2) ◽  
Author(s):  
C. Yang ◽  
B. N. J. Persson
Keyword(s):  
Molecular Dynamics ◽  
Contact Mechanics ◽  
Contact Area ◽  
Full Contact ◽  
Interfacial Separation

scholarly journals Contact mechanics with adhesion: Interfacial separation and contact area

2008 ◽  
Vol 84 (4) ◽  
pp. 46004 ◽  
Author(s):  
C. Yang ◽  
B. N. J. Persson ◽  
J. Israelachvili ◽  
K. Rosenberg
Keyword(s):  
Contact Mechanics ◽  
Contact Area ◽  
Interfacial Separation

scholarly journals A 3D study of the contact surface developed by the contact between the tires and the structural pavements

Exacta ◽  
2009 ◽  
Vol 6 (2) ◽  
pp. 197-208
Author(s):  
Alex Alves Bandeira ◽  
Rita Moura Fortes ◽  
João Virgílio Merighi
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Contact Area ◽  
Augmented Lagrangian Method ◽  
Numerical Results ◽  
Real Contact Area ◽  
The Real ◽  
Real Contact ◽  
Commercial Program ◽  
Contact Surfaces

The basic aim in this work is to present a new technique to analyze the contact surfaces developed by the contact between the tires and the structural pavements by numerical simulations, using 3D finite element formulations with contact mechanics. For this purpose, the Augmented Lagrangian method is used. This study is performed just putting the tires on the structural pavement. These tires and the structural pavement are discretized by finite elements under large 3D elastoplastic deformation. The real loads (of aircrafts, trucks or cars) are applied directly on each tire and by contact mechanics procedures, the real contact area between the tires and the pavement surface is computed. The penetration conditions and the contact interfaces are investigated in details. Furthermore, the pressure developed at the contact surfaces is automatically calculated and transferred to the structural pavement by contact mechanics techniques. The purpose of this work research is to show that the contact area is not circular and the finite element techniques can calculate automatically the real contact area, the real geometry and its stresses and strains. In the end of this work, numerical results in terms of geometry, stress and strain are presented and compared to show the ability of the algorithm. These numerical results are also compared with the numerical results obtained by the commercial program ANSYS.

Influence of the in-plan distribution of asperities on the normal contact of periodically rough surfaces

2016 ◽  
Vol 230 (9) ◽  
pp. 1382-1391
Author(s):  
K Houanoh ◽  
H-P Yin ◽  
J Cesbron ◽  
Q-C He
Keyword(s):  
Numerical Simulations ◽  
Half Space ◽  
Contact Area ◽  
Rough Surfaces ◽  
Elastic Half Space ◽  
Real Contact Area ◽  
Normal Contact ◽  
Real Contact ◽  
Full Contact ◽  
Rigid Surfaces

The present work aims to analyze the influence of the in-plan distribution of asperities on the contact between periodically rough surfaces. Square pattern and hexagonal pattern rigid surfaces are considered. Their contact with an elastic half-space is analyzed by numerical simulations. Three surfaces are generated with identical asperities periodically distributed in a plan according to different patterns. It follows from numerical results that when the load and the real contact area are small, the asperities act almost independently. However, the interaction between close asperities increases with the load becomes intensified and has a significant effect on the contact area when the situation is close to full contact.

Viscoelastic Contact of a Half-Plane Sliding Over a Slightly Wavy Rigid Surface

2014 ◽  
Author(s):  
N. Menga ◽  
C. Putignano ◽  
T. Contursi ◽  
G. Carbone
Keyword(s):  
Contact Problem ◽  
Contact Area ◽  
Analytical Procedure ◽  
Sliding Contact ◽  
Rigid Surface ◽  
Viscoelastic System ◽  
Contact Conditions ◽  
Partial Contact ◽  
Full Contact ◽  
Viscoelastic Contact

In this paper, the sliding contact of a rigid sinusoid over a viscoelastic halfplane is studied by means of an analytical procedure that reduced the original viscoelastic system to an elastic equivalent one, which has been already solved in [1]. In such a way, the solution of the original viscoelastic contact problem requires just to numerically solve a set of two integral equations. Results show the viscoelasticity influence on the solution by means of a detailed analysis of contact area, pressure and displacement distribution. A particular attention is paid to the transition from full contact to partial contact conditions.

scholarly journals The Role of Calcaneofibular Ligament (CFL) Injury in Ankle Instability

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0002
Author(s):  
Kenneth Hunt ◽  
Richard Fuld ◽  
Judas Kelley ◽  
Nicholas Anderson ◽  
Todd Baldini
Keyword(s):  
Contact Mechanics ◽  
Ankle Joint ◽  
Motion Capture ◽  
Contact Area ◽  
Subtalar Joint ◽  
Ankle Instability ◽  
Weight Bearing ◽  
Calcaneofibular Ligament ◽  
Tibiotalar Joint ◽  
Ankle Stability

Category: Ankle Introduction/Purpose: Acute inversion ankle sprains are among the most common musculoskeletal injuries. Higher grade sprains, which include anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injury, can be particularly problematic and often require surgical repair. The implications of CFL injury on ankle instability are unclear. We aim to evaluate the impact of CFL injury on ankle stability and subtalar joint biomechanics. We hypothesized that CFL injury will result in decreased stiffness and torque, and alteration of ankle contact mechanics compared to the uninjured ankle in a cadaveric model. Methods: Twenty matched cadaveric ankles dissected of skin and subcutaneous tissue were mounted to an Instron with 20° of ankle plantar flexion and 15° of internal rotation. Intact specimens were axially loaded to body weight, then underwent inversion stress along the anatomic axis of the ankle from 0 to 20° (simulating inversion injury) for three cycles. ATFL and CFL were sequentially sectioned, and inversion testing repeated for each condition. Stiffness and change in torque were recorded using an Instron, and pressure and contact area were recorded using a calibrated Tekscan sensor system. Inversion angle of the talus and calcaneus relative to the ankle mortise were recorded using a three-dimensional motion capture system. Paired t tests were performed for inter and intra-group comparisons. Results: Stiffness and torque did not significantly decrease after sectioning of the ATFL, but did decreased significantly after sectioning of CFL. Peak pressures in the tibiotalar joint decreased significantly following CFL release compared to both the uninjured ankle and ATFL-only release. Mean contact area significantly increased following CFL release compared to both the uninjured ankle and ATFL release. There was a concentration of force in the anteromedial ankle joint during weight-bearing inversion. However, the center-of-force shifts 1.22 mm posteromedial after CFL release relative to an intact ankle. Motion capture showed a significant and sequential increase in inversion angle of both the calcaneus and talus, after release of each ligament. There was significantly more inversion in the subtalar joint than the tibiotalar joint with weight-bearing inversion. Conclusion: There is significantly lower stiffness and torque with weight-bearing inversion of the ankle joint complex following injury to both ATFL and CFL, and sequentially greater inversion of the talus and calcaneus with progressive ligament injury. This corresponds to a significant shift in the center of force in the tibiotalar joint. CFL contributes considerably to lateral ankle stability, and sprains that include CFL injury result in substantial alteration of contact mechanics at the ankle and subtalar joints. Repair of CFL may be beneficial during lateral ligament reconstruction, potentially mitigating long-term consequences (e.g., articular damage) of a loose or incompetent CFL.

Elucidating the contact mechanics of aluminum silicon surfaces with Green's function molecular dynamics

2007 ◽  
Vol 102 (11) ◽  
pp. 113511 ◽  
Author(s):  
Carlos Campañá ◽  
Martin H. Müser ◽  
Colin Denniston ◽  
Yue Qi ◽  
Thomas A. Perry
Keyword(s):  
Molecular Dynamics ◽  
Green’S Function ◽  
Contact Mechanics ◽  
Green's Function ◽  
Silicon Surfaces ◽  
Aluminum Silicon
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