【摘要】 基于LY12铝、MB2镁、铅、2#铁和不锈钢等几种材料的弹性前驱波幅度随传播距离衰减的实验结果,应用含位错参量的速率相关本构方程,按照Gilman提议的位错运动速度的热激活模型,得出了LY12铝、MB2镁、铅的可动位错密度N0和拖曳应力0τ的下限值分别为106cm-2和0.1GPa量级,不锈钢的N0和0τ为108cm-2和1.5 GPa量级。根据弹性前驱波幅度衰减曲线,还得出了2#铁、不锈钢的有效粘性系数μ的上限值为104Pa.s量级。LY12铝、MB2镁的有效粘性系数μ的上限值为103Pa.s量级。更多还原

【Abstract】 Based on the experimental results of the elastic precursor attenuation along with propagation distance,with rate-dependent constitutive relation including dislocation parameters,and according to the thermally activated dislocation motion model proposed by Gilman,the lower bounds of the initial mobile dislocation densities N₀ and the drag stresses τ₀ have been obtained for LY12-aluminum,MB₂-magnesium and lead respectively on the order of 10⁶ cm^-2 and 0.1 GPa,but for stainless steel,N₀ and τ₀ are on the order of 10⁸ cm^-2 and 1.5 GPa.With the elastic precusor decay curve,the upper limits of the effective viscosity coefficient μ have been given also for LY12-aluminum and magnesium on the（order） of 10³ Pa·s,and for 2^#-iron and stainless steel on the order of 10⁴ Pa·s.更多还原