A parameter study of separation modes of adhering microcontacts

Title:
A parameter study of separation modes of adhering microcontacts
Creator:
Du, Yan (Author)
Adams, George G. (Author)
McGruer, Nicol E. (Author)
Etsion, Izhak (Author)
Language:
English
Publisher:
American Institute of Physics
Copyright date:
2008
Type of resource:
Text
Genre:
Articles
Format:
electronic
Digital origin:
born digital
Abstract/Description:
A finite element model was developed to study adhesion of elastic-plastic microcontacts in a previous investigation. An interesting result was the identification of two distinct separation modes, i.e. brittle and ductile separation. In the current study, that model is used to conduct a series of simulations to determine the influence of four nondimensional parameters (including the maximum load parameter) on the contact and on the separation modes. The results show that the parameter S (the ratio of the theoretical stress to the hardness) and δƒ/δc (representing the loading level) are the most important. Smaller S can only lead to brittle separation, while larger S can cause either separation mode depending on δƒ/δc. Ductile separation is more likely to occur at smaller δƒ/δc and brittle separation at greater δƒ/δc. The transition between the two separation modes occurs at about S = 1.2 (for δƒ/δc = 30) which corresponds to the theoretical stress for adhesion being 20% greater than the hardness. This result is qualitatively similar to the existing simplified analytical models, in that the adhesion energy, the hardness, and the loading level play important roles in the occurrence of ductile separation. However, there are important quantitative differences. Comparisons are also made with molecular dynamics simulations of a contact and with a fracture mechanics model of crack propagation.
Comments:
Originally published in Journal of Applied Physics, v.103, no.6 (2008). doi:10.1063/1.2874434
Subjects and keywords:
Contact mechanics
Electric switchgear
Microelectronics
adhesion
brittleness
cracks
ductile fracture
finite element analysis
hardness
mechanical contact
molecular dynamics method
plastics
Electrical and Electronics
Nanoscience and Nanotechnology
Permanent Link:
http://hdl.handle.net/2047/d20000888

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