DYNAMIC PRESSURE INVESTIGATION,

The primary objective of Project 1.8 was to evaluate dynamic pressure as a damage parameter. In addition an attempt was made to determine the damage effect of the long positive phase duration. A total of 27 14-ton trucks were exposed in Shots 3 and 6 of Operation CASTLE. The ground ranges were selected to obtain dynamic pressures comparable to those acting upon jeeps experiencing light to severe damage on Shot 10 of Operation UPSHOT-KNOTHOLE. The yield value realized on Shot 3 was too low to give any significant results. For each degree of damage sustained by the jeeps in Shot 6 dynamic pressures were recorded which are related to measured overpressure by use of the Rankine-Hugonoit equation. The damage results of Shot 6, CASTLE, compare favorably with that of Shot 10, UPSHOT-KNOTHOLE. Although valuable data were obtained in Operation CASTLE, it was not enough to conduct a meaningful analysis of the effect of the long positive phase on damage. The data obtained from Operation CASTLE were sufficient to evaluate dynamic pressure as a damage parameter and also to determine the magnitude of dynamic pressures required for specific damage to 14-ton trucks for the set of conditions as realized in Operation CASTLE. Author