Buckling analysis of filament-wound thick composite cylinder under hydrostatic pressure

Abstract

NOMENCLATURE E1,E2,E2 = Elastic Modulus G12,G23,G13 = Shear Modulus v12 ,v23, v13 = Poisson's ratio IntroductionUnderwater vehicles, that operate in deep water, are subjected to high external hydrostatic pressure. In general, the pressure hull of an underwater vehicle has a stiffened cylindrical shell structure, and the spherical or elliptic shells are attached to both ends. Shell is the structure often found in vessels, submarines, aircrafts, and buildings. Accordingly, there have been many studies on the analysis of shell structures, and the variety of shell theories has been suggested. In particular, when the shell undergoes a pressure load, the buckling can take place at a stress which is far lower than the material strength. Therefore, the compressive buckling strength of a shell should be taken into consideration. 1,2The performance of a structure can be improved if its weight is be reduced by using the low-density material such as a composite, compared to high strength steel, titanium alloy, and aluminum alloy. Experiments on composite buckling are limited by equipments and costs, and thus the finite element analysis (FEA) method is used to simulate the testing. 3 The FEA results for isotropic materials, such as metals, are in good agreement with experimental results. However, the FEA results for composite materials, that are anisotropic, can show a relatively large difference with experimental results. Accordingly, it is necessary to identify the problems with the FEA results and bridge the gaps by optimizing the finite element models.The majority of studies on conventional composites focus on composites made by prepreg method. 4,5 There are many studies on the bucking and postbucking of cylindrical shell, which are Underwater vehicles that operate in deep waters require a pressure hull to maintain the sufficient strength and stiffness against external hydrostatic pressure. We investigated the validity of the finite element method (FEM) that is applied to a buckling analysis of the filament-wound composite cylinder, subjected to an external hydrostatic pressure. Two methods were suggested for the buckling analysis of a filament-wound thick composite cylinder under hydrostatic pressure: using the equivalent properties of the composite, and using stacking sequence. The hydrostatic pressure test was conducted to verify the FEA. Test results were compared with the previous results obtained by FEM on the buckling of a filament-wound composite cylinder under hydrostatic pressure. FEM analysis results were in good agreement with the test results. The difference between FEM results and the test results was approximately 1~5%.

An empirical formula for predicting the collapse strength of composite cylindrical-shell structures under external pressure loads

“…Li and Lin (2010) calculated the nonlinear buckling and post-buckling of a moderately thick anisotropic laminated cylindrical shell based on a higher-order shear deformation shell theory. Hur et al (2008), Moon et al (2010), and Kim et al (2010) investigated the post-buckling behavior and failure of filament-wound composite cylinders using the nonlinear finite element method (NLFEM) and experiments. Deyet al (2014) numerically analyzed the post-buckling characteristics of moderately thick-walled composite cylinders using NLFEM.…”

“…Messager et al (2002) later developed an analytical buckling shell model based on third-order shear deformable theory and compared the results with NLFEM and experimental results. Kim et al (2010) and Jung et al (2012) compared two analytical buckling pressure formulations, i.e., the ASME and NASA formulas, with NLFEM or experimental results. Rao Yarrapragada et al (2012) used the Windenburg equation, which was developed for homogeneous materials, to predict the critical buckling pressure of composite shells with equivalent stiffness moduli, and compared the results with NLFEM.…”

Influence of ply angle and length on buckling behavior of composite shells under hydrostatic pressure

“…Kim et al. 23 developed the finite element technique to analyze the buckling of a filament-wound thick composite cylinder and performed a hydrostatic pressure experiment. Messager et al.…”

Local Buckling Analysis of T-Section Webs with Closed-Form Solutions

“…Lee and Bang developed an approach for estimation of lateral buckling of a wind turbine tower with a thin circular wall through finite element (FE) analysis to ensure structure safety [8]. Kim et al carried out a buckling analysis of filament-wound composite cylinder subject to deep water high hydrostatic pressure [9], and so forth.…”