Deepak Patil

Deepak Patil

Ph.D. Interfacial Mechanics in Progress M.S. Mechanical Engineering 2011 B.S. Mechanical Engineering 2006 Research Background: I am currently employed at Molex. My graduate research was mainly focused on interfacial mechanics; understanding friction and energy dissipation between contacting surfaces. Presliding friction is the resistance to tendency to move in stationary contacts. Behavior of a system with friction at the interface is inherently nonlinear. Nonlinearities associated to interfacial mechanics primarily are the onset of sliding and energy dissipation. Due to these nonlinearities it is extremely difficult to develop a predictive model for friction and damping. A physics based approach is essential to study the presliding regime. Understanding the major mechanisms involved in presliding would help in explaining both the onset of sliding and the energy dissipation. The mechanisms considered to investigate the presliding regime for this research are interfacial slip, plasticity and crack. An extended finite element model (XFEM) is used to simulate a rigid flat on a deformable sphere under combined normal and tangential loading at the asperity scale. Onset of sliding is treated as the tangential load resulting in nearly vanishing tangential stiffness, whereas energy dissipation is studied for small cyclic tangential loads. The results at the asperity scale show load-dependent friction coefficients and energy dissipation. The results from asperity scale are used as input in theoretical models (statistical summation approach) and finite element model to obtain global static coefficient of friction and global damping properties at the rough surface scale. The ultimate objective is to obtain a predictive/semi-predictive model for coefficient of friction and damping based on physical principles.