Exploring analysis of dynamic cushioning properties of water-entry missile's shock mitigator

Having pointed out that past research relies too much on empirical data, we try to explore what we believe to be a better method through somewhat more theoretical analysis. Sections 1 through 3 of the full paper explain in some detail the better method we explored. Its core consists of: (1) we utilize a constitutive relationship to express the stress-strain responses of high-density PUR (polyurethane) foams under uniaxial compression loading conditions; (2) we modify the constitutive relationship and derive eq. (4) in the full paper to do the numerical analysis of the missile's vertical water-entry impact. To validate the effectiveness of our method, we compare the effects of the different geometrical coefficients of the mitigator, the different densities of PUR foams and different water-entry velocities on dynamic cushioning performances. The comparison results, given in Figs. 4 through 9, show preliminarily that our method is more effective than the conventional method for accurately analyzing water-entry impact.