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This thesis presents a simulation model of sliding process of friction, which combines Newtonian particle dynamics and finite element method to study friction mechanisms that bridging micro and macro scales. In the thesis, it first reviews the importance of studying pavement friction that is associated to safety of drivers, society economics and environmental impact. Then, the hybrid numerical methods of Newtonian particle dynamics and finite element method have been introduced, and the rules to bridge these two methods also have been discussed for solid material that assumes the forces and displacements are continuous at the interface of these two methods. The fundamental theories of friction mechanisms are built upon the surface roughness, adhesion and deformation at the contact between two surfaces. At last, the simulation model of sliding process is presented with the hybrid method, and its visualization and result analysis has been given. At the same time, this thesis also includes the procedures of establishing the simulation of the hybrid methods with C++ programming like the program framework, structure and the major pieces of the program. / Master of Science

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MOND is an observational rule for predicting the acceleration of stars and galaxies from the distribution of the visible matter. It possibly stems from a new law of physics. I list the theoretical aspects of MOND, its achievements and problems. MOND has been tested mainly in disc galaxies so far. Its tests in elliptical galaxies are rare because the MOND effects are small for them in the parts observable by the conventional methods. In the thesis, I explain the methods and ideas I developed for testing MOND in the ellipticals using stellar shells. Moreover, the shells enable us to test MOND for stars in radial orbits for the first time. The shells are results of galactic interactions. I discuss the shell formation mechanisms and summarize the findings from shell observations and simulations.