We formulate a stochastic description about the mechanical response of an interface composed of non-covalent bonds. In such interfaces, the evolution of bonding probability in response to deformation plays the central role in determining their traction-separation behavior. The model connects atomistic and molecular level bonding properties to meso-scale traction-separation relationship in an interface. In response to quasi-static loading, the traction-separation of a stochastic interface is the resultant of varying bonding probability as a function of separation, and the bonding probability follows the Boltzmann distribution. The quasi-static stochastic interface model is applied to understand the critical force while detaching a sphere from an infinite half space. We further show the kinetics of interfacial debonding in the context of the Bell model (1978) and two of its derivatives - the Evans-Richie model (1997) and the Freund model (2009). While subjected to constant force, an interface creeps and its separation time curve shows typical characteristics seen during the creep of crystalline materials at high temperature. When we exert constant separation rate to an interface, interfacial traction shows strong rate-sensitivity with higher traction at faster separation rate. The model presented here may supply a guidance to bring the stochastic nature of interfacial debonding into theories on cracking initiation and growth during fatigue fracture. (C) 2014 The Author. Published by Elsevier Ltd.

[http://dx.doi.org/10.1016/j.jmps.2014.05.014]

The research reported is supported by Chinese Academy of Sciences (KJCX2-EW-L03), MOST 973 of China (No. 2012CB937500), and National Natural Science Foundation of China (11021262).

The article was published as:

Wei YJ. A Stochastic Description On The Traction-separation Law Of An Interface With Non-covalent Bonding[J].Journal Of The Mechanics And Physics Of Solids,2014,70:227-241.