Influence Of Environmental Factors On Corrosion Damage Of Structure By Molecular Dynamics Simulation

Molecular Dynamics method is a method to simulate the material properties on the Atomic size. It is a deterministic method for connect material microstructure and macroscopic properties. The corrosion damage of structure under the service environment is formation and expansion at atomic or nano-based size. Therefore, using this method to simulate the corrosion damage of structure must solve the traditional linear elastic fracture mechanics based on the continuum theory which cannot be resolved. What’s more, it makes the microcosmic field of crack initiation and propagation problems possible.In this aspect both at domestic and overseas, the evolution containing determine prefabricated micro-crack structure under external loads which are based on the molecular dynamics method had been analyzed. But there were rarely consideration about the micro-cracks initiation and extension under the environment at the structure surface which have the damage corrosion. Because of the complexity of mechanism of corrosion damage evolution in the environment, in this paper have done the following work mainly:(1)Review the economic damage of the metal corrosion and its research status are reviewed, and introduces the current research status of molecular dynamics method which is widely used.(2)Using the cellular automata method to simulate the evolution of corrosion damage, used the computer program established the cellular automata simulation model. Then, simulate the evolution mechanism of corrosion damage in complex environment, at last, the instantaneous image of corrosion damage evolution with time were obtaining.(3)Using the cellular automata simulation topography with image processing technology, and combined with the molecular dynamics method, established the molecular dynamics model of crack initiation, and applied myself programmed in VC environment, the corrosion damage of single crystal aluminum plate under the action of cyclic loading in the micro process of crack initiation is simulated.(4)At last, in the paper analyzed the energy and strain in the process of molecular dynamics, and the reliability of the simulation results is analyzed. The simulation results of this paper have provided theory basis for the structural life-cycle assessment under the action of the environment.