在位错动力学的Seeger方程基础上 ,引入周期场作用 ,把位错运动方程化为具有硬弹簧特性的Duffing方程 ,并利用多尺度法分析了系统的动力学特征 ,利用Melnikov方法讨论了系统的全局分叉和系统进入混沌状态的可能途径 .结果表明 ,当δ α一定 ,Ω不断减小时 ,系统逐渐向临界状态接近 ,然后经过无限次级联分叉进入混沌状态 Based on the Seeger equation of dislocation dynamics, the periodic field effect is introduced, the dislocation motion equation is transformed into the Duffing equation with hard spring characteristics, and the dynamic characteristics of the system are analyzed by multi-scale method. The Melnikov method is used to discuss the system The global bifurcation and the probable way for the system to enter the chaos state.The results show that when δ α is constant and Ω is decreasing, the system gradually approaches the critical state and then enters the chaos state through infinite sub-cascading bifurcation