A Measurement of Bending and Torsional Moments on Floating Box Type Barges in Oblique Regular Waves

Abstract

This paper presents the measured results of wave loads in model test basin, concerning the influence of Beam-draft ratio, by a systematic program. The motions with six degrees of freedom were measured simultaneously. The model has been chosen so as to have mean Length-Beam ratio of floating box type barges. The draft of barges in towing conditions is generally very shallow compared with ordinary ships, then three small draft conditions were selected to cover almost all Beam-draft range of barges. The model consists of four segments longitudinally jointed by load transducers of strain gauge type. The measurements were carried out in oblique regular waves with four different directions, at zero forward speed. Finally, comparing nondimensional measured results with those of ships with ordinary draft, it has become clear that the maximum value of vertical bending moment coefficient (M_v/ρgζ_aBL^2) showed almost the same magnitude, but of torsional moment coefficient (M_T/ρgζ_aBL^2) showed several times larger. The calculation by Ordinary Strip Method, done for reference, showed good coincidence with motions, but there were significant differences with wave loads.