温度和加载速率对位错发射影响的原子级模拟

Atomistic Simulation of the Influence of Temperature and Loading Rate on Dislocation Emission

以Al作为研究对象，采用EAM势实施分子动力学模拟．在Ⅰ型和Ⅱ型加载条件下，研究了温度和取向对位错发射、裂纹脆性及韧性扩展的影响．模拟结果表明，升高温度，发射位错的临界应力强度因子按指数规律降低．加载速率在一定范围内将影响临界应力强度因子．临界应力强度因子随着加载速率的增大而增大．

Utilizing EAM potential,Al single crystal with molecular dynamicssimulation method was studied. Under mode Ⅰ and Ⅱ loading, the influence of temperature and loading rate on dislocation emission and the criticalstress intensity factor was analyzed.The simulatedresults show that the critical stress intensity factor for dislocation emission decreases exponentiallyas the temperature increases. Loading rate will influence the critical stress intensity factor to some degree. The critical stress intensity factor will increase as loading rate increases.