Progressive Failure of Marine GFRP Laminated Plates Under Impulsive Water Pressure

Abstract

When fiber-reinforced plastic (FRP) crafts sail at high speed, very large slamming forces impact the bottom structures of crafts. Therefore, the capacity to resist these forces is an important factor when designing crafts. In the past, the instability and complexity of material properties in failure analysis, in addition to the difficulties in conducting the laminate failure experiments due to water impact, resulted in few studies investigating the failure progress of FRP laminates subjected to water impact. This study presents a novel impulsive water-pressure failure experimental system that combines a hydraulic system with a water-pressure failure experimental fixture used in previous work, to generate impulsive water pressure. Using this system, the FRP laminates are deformed and damaged under water impact. In numerical analysis, the finite element software ABAQUS and user subroutine user-defined field (USDFLD) are utilized to calculate the strain field of laminates as a basis of failure evaluation and stiffness degradation of a structure after specifying failure criteria and stiffness modification curve obtained from material tests for different materials. By comparison with experimental data, the numerical model can be validated, regardless of whether the impulsive water loads are sufficiently small or large to cause structure failure. Consequently, based on the results of this study, the abilities of analyzing the dynamic failure progress under out-of-plane impulsive water pressure and the corresponding experimental systems can be well established. Furthermore, the capacity of FRP laminates in resisting water pressure can also be elucidated.