JAPD 2007 Abstract
An Elastic-Plastic Finite Element Analysis of
Interacting Asperities in Contact with a Rigid Flat
Hassan Eid and George G Adams
Summary
A three-dimensional elastic-perfectly-plastic finite element model of asperity interaction has been developed. This model consists of two
connected neighboring deformable hemispheres which are brought into contact with a flat rigid surface. For two asperities of the same
height and same radius, as the approach of the rigid surface is increased, the contact area changes from two isolated nearly circular contacts,
to a wasp-waist area, and finally to a single oval shaped contact region. For asperities of different heights the results can be qualitatively
similar to those for equal heights, but can also exhibit a shielding effect in which the first contact grows to eventually encompass the second
lower peak. Results are given using dimensionless quantities for the force vs. interference, and the contact area vs. interference. These
relationships are plotted for different asperity height differences and asperity separations. Also provided are graphs of the contact area
boundary for different values of the approach. Curve-fit equations are presented as an aid in using this work as a building block in a statistical
multi-asperity contact model which directly includes the effect of asperity interactions.
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