应变超晶格系统的共振行为及其动力学稳定性

在经典力学框架内和Seeger方程基础上,讨论了应变超晶格界面附近的位错动力学行为,指出了系统的非线性共振将导致位错的运动与堆积,并可能造成超晶格的分层或断裂.首先,引入阻尼项,在小振幅近似下,把描述一般位错运动的Seeger方程化为了超晶格系统的广义Duffing方程.利用多尺度法分析了系统的主共振、超共振和子共振,并找到了系统出现这三类共振的临界条件.结果表明,系统的临界条件与它的物理参数有关,只需适当调节这些参数就可以原则上避免共振的出现,保证了超晶格材料的完整性和性能的稳定性. 关键词： 位错动力学 应变超晶格 共振 分岔

The resonance behaviour and dynamic stabilities of strained Superlattice

The dynamic behaviour in the vicinity of the interface for the strained superlattice is discussed in the classical mechanics frame based on the Seeger equation. We found that the motion and the accumulation of the dislocations by the non-linear resonance may give rise to the lamination or the fracture of the superlattice. At first, byintroducing the damping term,the Seeger equation describing the dislocation motion is reduced to the generalized Duffing equation describing superlattice in the small amplitude aproximation. Secondly,the main resonance, the super-harmonic resonance and the sub-harmonic resonance of the system are analysed by the multiscale method. The critical condition for the system to enter into resonance is found. It shows that the critical condition is related to the parameters of the system,by adeguately regulating the parameters of the system,the resonance can be avoided in principle,then the stability and the perfection of the superlattice materials may be bellev ensured.