Numerical Buckling Analysis And Optimization Of Cylindrical Shell Under Uniform Axial Compression

Thin cylindrical shells are widely used in modern structures, such as aviation, spaceflight, shipping, civil engineering, mechanical engineering and so on. When the related structures are under axial compression, inflectional destruction is the primary destroy format. A finite element analysis software ANSYS is applied in the dissertation with it's redeveloped language APDL. The main contents are included as follows:(1) The calculation model of thin-wall cylindrical shell is set up to study its capability. Comparing the numerical value with the theoretical value of no-stiffener cylindrical shell, the feasibility and analysis precision are comfirmed.(2) APDL, the redeveloped language of ANSYS, is executed to build optimization model of stiffened cylindrical shell with rectangle, box and I-shaped section stiffeners respectively. The objective of the optimization model is structure's load capacity, and the design variables are the thickness of shell and the sizes of stiffener, restricted in certain entire structure volume and top and bottom limitation of optimization parameters. A serial linear programming optimization procedure is performed to solve the model.(3) The optimization results of 7 different vertical and ring stiffeners patterns are obtained and compared to get reasonable stiffeners distribution and optimal sizes of stiffener, as well as to get diverse increasing effects of structure's load capacity in different conditions of different section shapes.The stiffeners distribution pattern, section shapes of stiffener and optimal results of stiffened cylindrical shell obtained in this paper are useful for stiffened shell design.