Failure analysis of a liquid natural gas (LNG) containment system – Bending failure of plywood component

Abstract

The main load-carrying component of the containment system of membrane gas carriers is made of plywood. One of the failure modes of the containment system due to violent liquid loading inside the tank is bending the plywood plate. A systematic study of the plywood bending failure is conducted by means of experiments and finite element (FE) methods. The objective is to propose an FE model that can replicate the nonlinear tests results of the plywood bending failure. The FE software ABAQUS has been utilized as a basis for this study. The material is modelled by linear elasticity combined with damage initiation using Hashin's theory. The brittle behaviour is indicated by linear softening. The softening is modelled by a fracture energy approach. The sensitivity study of the damage parameter on ultimate bending load is conducted. The numerical results from FE models are compared with the test results. A nonlinear material and FE model of plywood that could demonstrate the brittle failure is proposed.

Keywords:

• Finite element method
• strain measurement
• composite
• brittle fracture

Acknowledgements

The authors acknowledge funding from the Department of Marine Technology of the Norwegian University of Science and Technology, Trondheim, Norway.