Research On Ivalidation Of Delay Element Under High Acceleration Effect And Reinforce Technic

A Hopkinson pressure bar technique was used to test the burning performance of boron type delay charge pressed into the delay unit under overload with a high acceleration in this dissertation, in which the theoretical invalidation of the delay unit was analyzed, and two methods were used to improve the antioverload performance. The main works and achievements are presented as follows:The delay unit was tested under overload with a high acceleration. The results indicated that a portion of the delay charge was projected from the end of the delay unit during the course of the experiment, and the projecting quantity increased with the acceleration. The projecting mechanism was analyzed on the basis of the phenomena and data.Two methods, namely changing the dimension of the delay unit and adding exterior buffer spacers, were utilized to reinforce the delay unit under overload with a high acceleration. Increasing the diameter of the shell tube decreased remarkably the effect of high acceleration on burning rate of the delay charge and the projecting quantity. Change in the length of the shell tube had very little effect on the antioverload performance. Adding paper spacers at the ends of the delay unit decreased remarkably the projecting quantity and had better reinforcing effect than adding a paper spacer at only one end of it.Before/after changing the dimension of the delay unit or adding exterior buffer spacers, the burning process of boron type delay charge pressed into the delay unit under overload with a high acceleration was simulated with ANSYS/LS-DYNA. The simulation indicated that the delay charge was projected under overload with a high acceleration, and accorded with the experimental data.