Buckling Analysis Of Stiffened Circular Cylindrical Panels With Differential Quadrature Element Method

The differential quadrature method (DQM) is a numerical method developed only recently. The differential quadrature element method (DQEM) is a method based on the differential quadrature method together with the sub-domain and integrated techniques. DQEM overcomes the shortcoming of that the original DQM cannot be used for analyses of complex structures. The buckling behavior of stiffened circular cylindrical shells and stiffened circular cylindrical panels which widely used in fields of aerospace, mechanical, construction and marine engineering is a major concern by designers. In this thesis, the first attempt has been made to employ the DQEM for analyzing the stability problem of stiffened circular cylindrical panels to extend its application range. Firstly, the basic theories of DQM and DQEM are briefly introduced in this thesis. Then the new method to obtain the weight coefficients is used to derive the DQ circular cylindrical panel element, the DQ straight beam element and the DQ circular beam element. The detailed formulations and analysis procedures are given. Buckling of isotropic circular cylindrical panels, isotropic stiffened circular cylindrical panels and orthotropic stiffened circular cylindrical panels are analyzed by using the DQEM. The buckling loads and buckling modes are obtained. The DQEM results are compared with existing data to verify the established formulations, analysis procedures and DQEM results. And some new results are also given for readers'reference. Numerical results indicate that the established formulations and analysis procedures are correct. It is also shown that the DQEM has advantages of simple, good convergence rate, low computation effort and high accuracy.