Membrane Hull Technology Implemented into a D-Collar Work Boat
Abstract
Membrane Hull Technology (MHT) was initially developed for the United States
Navy Rigid-Hull Inflatable Boats (RHIB) as an alternative structure design to
provide weight savings and shock mitigation. MHT accomplishes this by veering
away from traditional hull design and utilizing a grid like system with an increased
number of longitudinal stringers and transverse frames with a significantly lower
moment of inertia when compared to traditional stringers and bulkheads. The
decrease in stiffness allows for increased deflection in the hull during high load
events with the added benefit of shock absorption. This technology, developed by
Structural Composites Inc., has been successfully implemented into multiple Navy
RHIBs.
To date, this technology has not been applied into a D-Collar work boat that has
various design differences when compared to RHIBs. The main design difference
examined will be converting the large, structural freeboard away from traditional
cored structure to a thin walled framed structure. Other design differences examined
include the integration of an Armstrong bracket, the hull to deck interaction and the
various workloads and equipment seen on the D-Collar workboat. Finite Element
Analysis was conducted to optimize the structural laminate while conforming to design standards to decrease the structure mass by greater than 40%. Analysis
showed hull deflections greater than 4 cm which validated the theory of Membrane
Hull Technology as a shock mitigation structure by increasing the time and distance
over which accelerations are applied to the craft.