scholarly journals Adhesive and adhesiveless contact mechanics of elastic layers on slightly wavy rigid substrates

2016 ◽  
Vol 88-89 ◽  
pp. 101-109 ◽  
Author(s):  
N. Menga ◽  
L. Afferrante ◽  
G. Carbone
Keyword(s):  
Contact Mechanics ◽  
Elastic Layers

scholarly journals Contact Mechanics of Rough Surfaces in Hermetic Sealing Studies

2018 ◽  
Author(s):  
Peter Ogar ◽  
Sergey Belokobylsky ◽  
Denis Gorokhov
Keyword(s):  
Contact Mechanics ◽  
Rough Surfaces ◽  
Hermetic Sealing

Dissecting Contact Mechanics from Quantum Interference in Single-Molecule Junctions of Stilbene Derivatives

Nano Letters ◽  
2012 ◽  
Vol 12 (3) ◽  
pp. 1643-1647 ◽  
Author(s):  
Sriharsha V. Aradhya ◽  
Jeffrey S. Meisner ◽  
Markrete Krikorian ◽  
Seokhoon Ahn ◽  
Radha Parameswaran ◽  
...  
Keyword(s):  
Contact Mechanics ◽  
Single Molecule ◽  
Quantum Interference ◽  
Single Molecule Junctions ◽  
Stilbene Derivatives

Discrete element and finite element methods provide similar estimations for hip joint contact mechanics during walking gait

2021 ◽  
Vol 115 ◽  
pp. 110163
Author(s):  
Mao Li ◽  
Mikko S. Venäläinen ◽  
Shekhar S. Chandra ◽  
Rushabh Patel ◽  
Jurgen Fripp ◽  
...  
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Hip Joint ◽  
Finite Element Methods ◽  
Discrete Element ◽  
Walking Gait ◽  
Joint Contact

Lateral Extra-articular Tenodesis Alters Lateral Compartment Contact Mechanics under Simulated Pivoting Maneuvers: An In Vitro Study

2021 ◽  
pp. 036354652110282
Author(s):  
Niv Marom ◽  
Hamidreza Jahandar ◽  
Thomas J. Fraychineaud ◽  
Zaid A. Zayyad ◽  
Hervé Ouanezar ◽  
...  
Keyword(s):  
Contact Mechanics ◽  
Contact Force ◽  
Contact Stress ◽  
Tibial Plateau ◽  
Cruciate Ligament ◽  
In Vitro Study ◽  
Lateral Compartment ◽  
Lateral Tibial Plateau ◽  
Intact Knee

Background: There is concern that utilization of lateral extra-articular tenodesis (LET) in conjunction with anterior cruciate ligament (ACL) reconstruction (ACLR) may disturb lateral compartment contact mechanics and contribute to joint degeneration. Hypothesis: ACLR augmented with LET will alter lateral compartment contact mechanics in response to simulated pivoting maneuvers. Study Design: Controlled laboratory study. Methods: Loads simulating a pivot shift were applied to 7 cadaveric knees (4 male; mean age, 39 ± 12 years; range, 28-54 years) using a robotic manipulator. Each knee was tested with the ACL intact, sectioned, reconstructed (via patellar tendon autograft), and, finally, after augmenting ACLR with LET (using a modified Lemaire technique) in the presence of a sectioned anterolateral ligament and Kaplan fibers. Lateral compartment contact mechanics were measured using a contact stress transducer. Outcome measures were anteroposterior location of the center of contact stress (CCS), contact force from anterior to posterior, and peak and mean contact stress. Results: On average, augmenting ACLR with LET shifted the lateral compartment CCS anteriorly compared with the intact knee and compared with ACLR in isolation by a maximum of 5.4 ± 2.3 mm ( P < .001) and 6.0 ± 2.6 mm ( P < .001), respectively. ACLR augmented with LET also increased contact force anteriorly on the lateral tibial plateau compared with the intact knee and compared with isolated ACLR by a maximum of 12 ± 6 N ( P = .001) and 17 ± 10 N ( P = .002), respectively. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress by 0.7 ± 0.5 MPa ( P = .005) and by 0.17 ± 0.12 ( P = .006), respectively, at 15° of flexion. Conclusion: Under simulated pivoting loads, adding LET to ACLR anteriorized the CCS on the lateral tibial plateau, thereby increasing contact force anteriorly. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress at 15° of flexion. Clinical Relevance: The clinical and biological effect of increased anterior loading of the lateral compartment after LET merits further investigation. The ability of LET to anteriorize contact stress on the lateral compartment may be useful in knees with passive anterior subluxation of the lateral tibia.

scholarly journals Micro-mechanical investigation of railway ballast behavior under cyclic loading in a box test using DEM: effects of elastic layers and ballast types

2019 ◽  
Vol 21 (4) ◽  
Author(s):  
Nishant Kumar ◽  
Bettina Suhr ◽  
Stefan Marschnig ◽  
Peter Dietmaier ◽  
Christof Marte ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Early Stage ◽  
Damage Model ◽  
Simulation Models ◽  
Railway Track ◽  
Maintenance Cost ◽  
Particle Movement ◽  
Railway Ballast ◽  
Elastic Layers ◽  
The Impact

Abstract Ballasted tracks are the commonly used railway track systems with constant demands for reducing maintenance cost and improved performance. Elastic layers are increasingly used for improving ballasted tracks. In order to better understand the effects of elastic layers, physical understanding at the ballast particle level is crucial. Here, discrete element method (DEM) is used to investigate the effects of elastic layers – under sleeper pad ($$\text {USP}$$USP) at the sleeper/ballast interface and under ballast mat ($$\text {UBM}$$UBM) at the ballast/bottom interface – on micro-mechanical behavior of railway ballast. In the DEM model, the Conical Damage Model (CDM) is used for contact modelling. This model was calibrated in Suhr et al. (Granul Matter 20(4):70, 2018) for the simulation of two different types of ballast. The CDM model accounts for particle edge breakage, which is an important phenomenon especially at the early stage of a tamping cycle, and thus essential, when investigating the impact of elastic layers in the ballast bed. DEM results confirm that during cyclic loading, $$\text {USP}$$USP reduces the edge breakage at the sleeper/ballast interface. On the other hand, $$\text {UBM}$$UBM shows higher particle movement throughout the ballast bed. Both the edge breakage and particle movement in the ballast bed are found to influence the sleeper settlement. Micro-mechanical investigations show that the force chain in deeper regions of the ballast bed is less affected by $$\text {USP}$$USP for the two types of ballast. Conversely, dense lateral forces near to the box bottom were seen with $$\text {UBM}$$UBM. The findings are in good (qualitative) agreement with the experimental observations. Thus, DEM simulations can aid to better understand the micro-macro phenomena for railway ballast. This can help to improve the track components and track design based on simulation models taking into account the physical behavior of ballast. Graphical Abstract

Bounds on the Maximum Contact Stress of an Indented Elastic Layer

1971 ◽  
Vol 38 (3) ◽  
pp. 608-614 ◽  
Author(s):  
Y. C. Pao ◽  
Ting-Shu Wu ◽  
Y. P. Chiu
Keyword(s):  
Half Space ◽  
Contact Stress ◽  
Elastic Layer ◽  
Theory Of Elasticity ◽  
Contact Conditions ◽  
Practical Applications ◽  
Method Of Solution ◽  
Elastic Layers ◽  
Maximum Contact ◽  
Contact Stress Distribution

This paper is concerned with the plane-strain problem of an elastic layer supported on a half-space foundation and indented by a cylinder. A study is presented of the effect of the contact condition at the layer-foundation interface on the contact stresses of the indented layer. For the general problem of elastic indenter or elastic foundation, the integral equations governing the contact stress distribution of the indented layer derived on the basis of two-dimensional theory of elasticity are given and a numerical method of solution is formulated. The limiting contact conditions at the layer-foundation interface are then investigated by considering two extreme cases, one with the indented layer in frictionless contact with the half space and the other with the indented layer rigidly adhered to the half space. Graphs of the bounds on the maximum normal stress occurring in indented elastic layers for the cases of rigid cylindrical indenter and rigid half-space foundation are obtained for possible practical applications. Some results of the elastic indenter problem are also presented and discussed.

scholarly journals Contact Mechanics of a Small Icosahedral Virus

2017 ◽  
Vol 119 (3) ◽  
Author(s):  
Cheng Zeng ◽  
Mercedes Hernando-Pérez ◽  
Bogdan Dragnea ◽  
Xiang Ma ◽  
Paul van der Schoot ◽  
...  
Keyword(s):  
Contact Mechanics ◽  
Icosahedral Virus
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