Atomistic Simulation of Fatigue Crack Growth in α-Fe under High Temperature
The crack growth behaviors loaded in mode I under strain and stress control at different temperatures were presented in α-Fe by atomistic simulations using LAMMPS code.The interatomic bonds of atoms were characterized using the embedded atom method interatomic potential.The simulation models were built with initial edge crack subjecting to cyclic uniaxial constant strain rate and constant stress.A temperature range from 100 K to 1200 K was considered to probe the influence of the temperature on crack growth.The crack growth mechanism and the radial distrinution function (RDF) during crack growth were investigated.The results indicated that the crack propagation mechanisms were sensitive to temperature and the boundary conditions.By proposed image adjusting technology the dislocation slip bands can be more clearly displayed on screen.In order to include the effect of temperature on crack growth, a temperature factor defined as a function of temperature in exponential form was introduced to modify the theoretical expressions based on thermal activation theory.Its coefficent and index can be determined by the RDF peak value obtained from atomistic simulations.For cyclic loading the crack growth process was dependent on both temperature and cyclic loading period in terms of simulations.
Molecular simulation Fatigue crack growth High temperature Iron Thermal activation
Tong Liu Minshan Liu
Thermal Energy Engineering Research Center of Zhengzhou University,Zhengzhou 450002,China
国际会议
2014 International Symposium on Structural Integrity,ISSI2014(2014国际结构完整性学术会议)
兰州
英文
233-242
2014-08-20（万方平台首次上网日期，不代表论文的发表时间）