Micromechanics of Rough Surface Adhesion: A Homogenized Projection Method
A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for the homogenized cohesive zone (HCZ) of a rough interface can be highly oscillatory due to instabilities during microscopic adhesion and decohesion processes. The instabilities are found to occur not only individually but also collectively among the adhesive micro-asperity contacts, leading to extensive energy dissipation. Based on the behaviors of the HCZ relations, a framework for describing instability-induced energy dissipation in rough-surface adhesion is proposed to elucidate the effect of roughness on apparent interface adhesion. Two non-dimensional parameters, α related to roughness morphology and n related to flaw distribution, are identified to be most crucial for controlling the energy dissipation. For an interface with a shallow roughness and a strong intrinsic adhesive strength, the interface adhesion can be stronger if we make it rougher (reducing α) or lower its flaw density (increasing n). The HCZ projection method can be potentially extended and employed to bridge the apparent adhesion from intrinsic adhesion properties for engineering surfaces with multi-scale shallow roughness.
Key wordshomogenized cohesive zone interface adhesion roughness effect instability energy dissipation
Unable to display preview. Download preview PDF.
- Adams, R.D., Comyn, J. and Wake, W.C., Structural Adhesive Joints in Engineering (2nd Edition). London: Chapman & Hall, 1997.Google Scholar
- Hjortso, M.A. and Roos, J.W., Cell Adhesion: Fundamentals and Biotechnological Applications. Boca Raton, FL: CRC Press, 1994.Google Scholar
- Israelachvili, J.N., Intermolecular and Surface Forces. (2nd Edition). London: Academic Press, 1992.Google Scholar
- Kendall, K., Molecular Adhesion and Its Applications: The Sticky Universe. Berlin, Germany: Springer, 2001.Google Scholar
- Drelich, J., Adhesion forces measured between particles and substrates with nano-roughness. Minerals and Metallurgical Processing, 2006, 23: 226–232.Google Scholar
- Buzio, R. and Valbusa, U., Interfacial stiffness and adhesion of randomly rough contacts probed by elastomer colloidal AFM probes. Journal of Physics: Condensed Matter, 2008, 20: 354014.Google Scholar
- Westergard, H.M., Bearing pressures and cracks. Journal of Applied Mechanics, 1939, 6: 49–53.Google Scholar
- Tada, H., Paris, P.C. and Irwin, G.R., The Stress Analysis of Cracks Handbook (2nd Edition), St Louis, MO: Paris Productions, 1985.Google Scholar