AIRFRAME WATER IMPACT ANALYSIS USING A COMBINED MSC/DYTRAN - DRI/KRASH APPROACH

This paper describes a Naval Air Warfare Center (NAWC) sponsored Small Business Innovation Research (SBIR) Phase I Program to achieve long-range U.S. Navy water impact design objectives. In this program, a complementary approach utilizing both a nonlinear finite-element analysis program (MSC/DYTRAN) and a hybrid impact analysis code (DRI/ KRASH) is used to demonstrate the potential for airframe water impact analysis. Several water impact conditions were analyzed comprising various combinations of forward velocity and sink speed using MSC/DYTRAN and DRI/KRASH. Sampling of results along with test data are provided with regard to fuselage underside pressure contours, floor accelerations, airframe-water interactive forces, response comparisons and trends. No similar results have previously been presented.