Multiscale Modelling of Meso and Nano Scale Interfacial Dynamics Phenomena

The proposed research programme concerns the development of multiscale methods based on the coupling of continuum and molecular dynamics. Multiscale methods aim to enable the simulation of complex problems such as the study of interfacial friction in materials subjected to shock waves, as well as to provide a meso scale modelling strategy for the range of length and time scales, where molecular methods are computationally expensive and continuum methods are not sufficiently accurate. The research programme includes the development of hybrid solution interface (HSI) for coupling multiscale domains; a dynamic-feedback coupling (DFC) strategy; implementation of constitutive equation to account for the elastic-plastic behaviour in the stress-tensor calculation; verification and validation studies; and computational studies of interfacial dynamics phenomena under shock wave conditions. The verification and validation studies include comparisons of the multiscale methods against previous molecular dynamic simulations for sliding interfaces and experimental data from HE-driven dynamic-friction experiments provided by AWE. Both small and large scale simulations of shock wave propagation and sliding interfaces will be carried out to gain insight into: (i) fracture and breaking of small parts of the surface; (ii) change of the geometrical shape of the surface or interface; (iii) melting and formation of a liquid layer; (iv) solidification of temporarily liquefied parts of the surface; (v) structural changes in the materials.