Nonlinear Buckling Analysis Of Plates And Shells With Finite Element Method

As the composite is widely used in the industry, the buckling and post-buckling of composite plates and shells are concerned by lots of engineers. This thesis is to study such an issue with the commercial software MSC. NASTRAN. Firstly, to verify the finite element model and the analysis procedures, the buckling of rectangular plates subjected to in-plane uniform and linear distributed load are analyzed. Results are agreed well with data in"Aircraft Design Manual"for most cases. It is found that, however, a few data in the"Manual"are not accurate enough and the correct results are provided. The buckling of the stiffened composite plates under biaxial loads is also analyzed. The possible reasons are given for larger discrepancy between present FE data with existing experimental and analytical results. Secondly, the buckling problems of rectangular plates suffered to nonlinear in-plane distributed load are solved for three typical boundary conditions. The equivalent buckling factors and their formulae are provided for the convenience to designers. Thirdly, the nonlinear stability of sphere shells, cylindrical shells and stiffened cylindrical shells is studied. The buckling and post-buckling path are given and compared with data in literature to verify the FE model and the solution procedures once again for the nonlinear buckling analysis of shells. Fourthly, the nonlinear buckling analyses of double curved stiffened composite shells subjected to the transverse concentrative load, shear force, and the combined loading of the two are performed. The buckling and post-buckling behavior is provided, and correlative curves of critical loading are given. The results may be useful for designers to design such types of double curved shells. They may be also useful for researcher to analyze nonlinear buckling problems of shells by using new methods.