Numerical Calculation of Pulse Rise-time of Extensive Shock Wave in Hopkinson Pressure Bar

Using nonlinear dynamic finite element program ANSYS/LS-DYNA and the shock pulse width formula of Hopkinson pressure bar,the shock-wave width engendered by cone-shaped bullets incident upon the Hopkinson bar was calculated and the pulse rise-time was analyzed.The calculated results show that,compared to cylindrical bullets with the same length and radius,the conical bullets can engender much longer pulse width,and there is not much difference between the pulse widths caused by copper and steel bullets;with increase of the cone angle,the pulse width and rise-time generated by bullets increase first and then decrease,but the ratio of the rise-time in the total pulse increases only;for conical bullets,the increase of their radius can increase the pulse width and pulse rise-time,of which the ratio is constant almost.