Dynamic Contact Mechanics of Geologic Materials: Experiments, Modeling and Applications

Wear of the ultra-high molecular weight polyethylene (UHMWPE) tibial component of total knee replacements (TKR) depends upon the contact with the femoral component during motion. This study aimed to determine the dynamic contact mechanics within the tibiofemoral joint of a TKR while in a force-controlled knee simulator and to track the kinematics of the TKR system while in the wear simulator. These results were compared with those found in literature by the currently used simulator methods. Using a high-speed camera system, grey scale images of the contact between a transparent TKR tibial insert and the metal femoral component were captured with an industrial grade fiberscope mounted below the tibial insert within the simulator. The analysis of the images yielded quantification of contact area and its location on the tibial insert. The results compare well with those found in literature. Therefore, it has been shown that the novel instrumentation designed for this project is an accurate and feasible method to determine contact area and location on a TKR tibial insert under dynamic loading.

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Dynamic contact mechanics on the tibial plateau of the human knee during activities of daily living

Journal of Biomechanics ◽

10.1016/j.jbiomech.2013.11.003 ◽

2014 ◽

Vol 47 (9) ◽

pp. 2006-2012 ◽

Cited By ~ 46

Author(s):

Susannah Gilbert ◽

Tony Chen ◽

Ian D. Hutchinson ◽

Dan Choi ◽

Clifford Voigt ◽

...

Keyword(s):

Activities Of Daily Living ◽

Contact Mechanics ◽

Daily Living ◽

Tibial Plateau ◽

Dynamic Contact ◽

Human Knee

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Dynamic and impact contact mechanics of geologic materials: Grain-scale experiments and modeling

10.1063/1.4811907 ◽

2013 ◽

Cited By ~ 1

Author(s):

David M. Cole ◽

Mark A. Hopkins ◽

Stephen A. Ketcham

Keyword(s):

Contact Mechanics ◽

Geologic Materials

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Contact Mechanics of a High Load Capacity Piston Pin

STLE/ASME 2008 International Joint Tribology Conference ◽

10.1115/ijtc2008-71121 ◽

2008 ◽

Cited By ~ 1

Author(s):

Don Cao ◽

Gary L. Doll

Keyword(s):

Film Thickness ◽

Contact Mechanics ◽

Diesel Engines ◽

Load Capacity ◽

Three Dimensional ◽

Dynamic Contact ◽

High Load ◽

Lubricant Film Thickness ◽

Connecting Rod ◽

High Load Capacity

A novel piston pin design is proposed for diesel engines having higher load capacity than current pin designs. This shaped piston pin incorporates a stress-reducing profile with lubricant film thickness enhancing features on the surface. Three dimensional FEA models were built and are used to model the dynamic contact between the piston and connecting rod interfaces with a standard piston pin and the new piston pin design.

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A method to measure pores and fissures in geologic materials under S.E.M. by digital image processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108209 ◽

1978 ◽

Vol 36 (1) ◽

pp. 212-213

Author(s):

L. Montoto ◽

M. Montoto ◽

A. Bel-Lan

Keyword(s):

Image Processing ◽

Optical Microscopy ◽

Digital Image Processing ◽

Digital Image ◽

Digital Processing ◽

Free Surfaces ◽

Geologic Materials ◽

Automatic Information ◽

Detector Output ◽

Rock Specimens

INTRODUCTION.- The physical properties of rock masses are greatly influenced by their internal discontinuities, like pores and fissures. So, these need to be measured as a basis for interpretation. To avoid the basic difficulties of measurement under optical microscopy and analogic image systems, the authors use S.E.M. and multiband digital image processing. In S.E.M., analog signal processing has been used to further image enhancement (1), but automatic information extraction can be achieved by simple digital processing of S.E.M. images (2). The use of multiband image would overcome difficulties such as artifacts introduced by the relative positions of sample and detector or the typicals encountered in optical microscopy.DIGITAL IMAGE PROCESSING.- The studied rock specimens were in the form of flat deformation-free surfaces observed under a Phillips SEM model 500. The SEM detector output signal was recorded in picture form in b&w negatives and digitized using a Perkin Elmer 1010 MP flat microdensitometer.

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