Structural Design and Response in Collision and Grounding

efore the hull ruptures. In such cases, the me mbranetensionphase includes two sub-phases: (1) there is notransverse movement of the web frames flanking thestrike; and (2) the web frames flanking the strike moveinward toward the ship’s centerline, and the damageextends into the adjacent web frame spaces. During thesephases, the deck is also distorting in membrane tension.However, the deck behavior is assumed not to affect thesequences of the options.Other sequences of phenomena are possible. A hullwith longitudinal stiffeners, such as rectangular bars thatare not apt to buckle or trip, tend to rupture beforesignificant membrane tension has a chance to develop.Alternatively, with any type of hull stiffeners, veryweak web frames can yield or buckle before rupture orbuckling of the longitudinal stiffeners, in which case thedamaged length increases during the bending phase.These phenomena are unlikely, however, for typicalships.Figure 38 - Macro flow diagram for side collision plastic-energy analysis of a double hull [24]21