Dr. Shank S. Kulkarni
Advanced Computing, Mathematics and Data Division
Pacific Northwest National Laboratory

Origin and Prevention of Spurious Reflections Arising During Local-to-nonlocal Coupling

ABSTRACT: Simulating a crack propagation is always a challenging task. Traditional numerical methods such as finite element methods (FEM) are not capable of handling such tasks because of the discontinuity in the displacement field across the crack. Therefore, a new method called ‘Peridynamics’ was introduced to remove deficiencies associated with traditional methods. Peridynamics (PD) can model a crack propagation naturally due to its nonlocal integral formulation. However, PD is computationally expensive and has some disadvantages. The best way to avoid all disadvantages is to couple PD with the finite element. In this method, PD is used only in critical areas such as the vicinity of the crack tip and FEM is used everywhere else.

The main issue associated with such coupling is the spurious wave reflections occurring at the interface of PD and finite elements. First, this issue is studied analytically to understand the effect of different parameters on the strength of spurious waves. Then, a new coupling method is proposed which gets rid of spurious reflection with the help of viscous damping.

BIOGRAPHY: Dr. Shank S. Kulkarni is working as Post Doctorate Research Associate in Advanced Computing, Mathematics and Data Division of Pacific Northwest National Laboratory at Richland, Washington. He received a Ph.D. degree in Mechanical Engineering from the University of North Carolina at Charlotte in the summer of 2019, under the advisement of Prof. Alireza Tabarraei. He also received a master’s degree in mechanical engineering from the Indian Institute of Technology, Bombay. Dr. Kulkarni also worked in the industry for two years in Whirlpool Corp., where he worked as Global Project Engineer. His research is mainly focused on peridynamics, material modeling, crystal plasticity, fracture mechanics and polymer composites. In his free time, he creates short movies for his YouTube channel 'Shank Kulkarni' on various topics.