Multiscale Modelling of Molecules and Continuum Mechanics Using Bridging Scale Method

his PhD dissertation is about developing a multiscale methodology for coupling two different time/length scales in order to improve properties of new space materials. Since the traditional continuum mechanics models cannot describe the influence of the nanostructured upon the mechanical properties of materials and full atomistic description is still computationally too expensive, millions of degrees of freedom are needed just for modeling few hundred cubic nanometers, this leads to a coupled system of equations of finite element (FE) in continuum and molecular dynamics (MD) in atomistic domain. Coupling efficiently and accurately two dissimilar domains presents challenges especially in handshaking area where the two domains interact and transfer information. The objective of this study is (i) develop a novel nodal position FE method that can couple with the MD easily, (ii) develop a proper methodology to couple the FE with MD for FE/MD multi-scale modeling and let the information transfer in a seamless manner between the two domains, and (iii) implement complicated cases to confirm accuracy and validity of the proposed model.