Hull Girder Response of Carrier Model with a Modified V-Bow in Regular and Random Head Waves

摘要

Tests were performed in regular and random head waves on a segmented structural model of the aircraft carrier USS ESSEX (CVA-9) whose forebody had been modified to a V-bow. The objective was to determine the effect of the bow modification on the vertical bending moment response of the hull girder. Measurements taken included time histories of the bending stress, pitch angle, heave displacement, wave height, and wave length. V-bow test results were compared for regular and random head waves series and with the original ESSEX bow results. The very good correlation between the regular and random wave Response Amplitude Operators (RAO) gives confidence in the test results. Test results for the V-bow showed a decrease in bending moment at the quarter points compared to those of the original ESSEX bow but hardly any change at midships. In the case of the bending moment RAO, there was a slight shift in the RAO's peak towards the higher wave frequency (i.e., lower wave lengths). A slight decrease in the pitch RAO was also noted. This study was limited to the quasi-static hull girder responses at zero model speed. (Author)