Scale Effects of Elastic-Plastic Behavior of Microscopic Asperity Contacts

Scale effects of elastic-plastic asperity microcontact behavior are studied theoretically using a new simulation method developed by the authors. Contact plastic deformation is described in terms of discrete dislocations, which allows the model to be made scale-sensitive. The present work deals with two-dimensional asperity microcontacts. It is found that when asperity size decreases and becomes comparable to the characteristic microstructural length, contact plastic deformation becomes increasingly difficult, and finally impossible. The effect of a simultaneous decrease in the asperity size and the microstructural length is also studied.