Implementation of Life Estimation Algorithm of Composite High Speed Craft Shell due to Cyclic Sea Pressure

According to increasing use of composites in high speed craft and exposing continuously to cyclic load, in this research, implementation of fatigue life estimation algorithm of composite shell of high speed craft has been done. The selected fatigue model which is based on reduction of mechanical properties and damage variable is introduced. This model has been implemented in finite element code (abaqus) with UMAT subroutine and validated with available results. Then, by using slamming load calculated from DNVGL standard and craft properties, the shell thickness is determined and fatigue life of the shell is analyzed with the faigue model due to the cyclic sea pressure. The results show that, the used faigue model has adequate ability for impelementation in the FEM software to fatigue life estimation and if the shell is designed with slamming pressure and assumed safety factor, the fatigue life due to cyclic sea pressure will be very high.