An incremental Total Lagrangian Formulation is implemented for the analysis of filament wound pressure vessel with consideration of the material and geometric nonlinearities. In the present study, the degenerated finite shell element is implemented for the analysis. This element takes into account the variations of the winding angle and the thickness along the meridional line of the vessel. This model can also represent geometrical nonlinear behavior by considering large displacements/large rotations. For large displacement/large rotation shell problems, the incremental equations are derived using a quadratic approximation for the increment of the reference vectors in terms of the nodal rotation increments. This approach leads to a complete tangent stiffness matrix. For material nonlinearity, the analysis is performed by using the piecewise linear method, taking account of the nonlinear shear stress-strain relation. The results of numerical tests include the large deflection behavior of the selected composite shell problem. When compared with the previous analysis, the results are in good agreement with them. The filament wound pressure vessel is analyzed with consideration of the geometrically and materially nonlinearity. The numerical results agree fairly well with the existing experimental results.
The burst failure of the filament wound pressure vessel composed of T-800 graphite/epoxy is studied with consideration of the geometric nonlinearity. A particular concern is made in predicting the propagation of damage after initial failure and the burst pressure of the filament wound pressure vessel as a function of applied load. In order to predict the burst pressure, a progressive failure analysis is performed by using a failure criteria with a property degradation model. Experiments is also conducted to measure the strains and the burst pressure of the filament wound pressure vessel. A fairly good agreement is obtained between the analysis and the test results.
