Type of Document Dissertation Author Gerhard, Craig Steven URN etd-05222007-091415 Title Finite element analysis of geodesically stiffened cylindrical composite shells using a layerwise theory Degree PhD Department Engineering Mechanics Advisory Committee
Advisor Name Title Gürdal, Zafer Committee Co-Chair Kapania, Rakesh K. Committee Co-Chair Keywords
- Composite construction.
- Shells (Engineering)
Date of Defense 1994-06-01 Availability restricted AbstractLayerwise finite element analyses of geodesically stiffened cylindrical shells are presented In this work. The layerwise laminate theory of Reddy (LWTR) is developed and adapted to circular cylindrical shells. The Ritz variational method is used to develop an analytical approach for studying the buckling of simply supported geodesically stiffened shells with discrete stiffeners. This method utilizes a Lagrange multiplier technique to attach the stiffeners to the shell. The development of the layerwise shells couples a one-dimensional finite element through the thickness with a Navier solution that satisfies the boundary conditions. The buckling results from the Ritz discrete analytical method are compared with smeared buckling results and with NASA Testbed finite element results.
The development of layerwise shell and beam finite elements is presented and these elements are used to perform the displacement field, stress, and first-ply failure analyses.
The layerwise shell elements are used to model the shell skin and the layerwise beam elements are used to model the stiffeners. This arrangement allows the beam stiffeners to be assembled directly into the global stiffness matrix. A series of analytical studies are made to compare the response of geodesically stiffened shells as a function of loading, shell geometry, shell radii, shell laminate thickness, stiffener height, and geometric nonlinearity.
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access LD5655.V856_1994.G474.pdf 7.02 Mb 00:32:29 00:16:42 00:14:37 00:07:18 00:00:37next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.
If you have questions or technical problems, please Contact DLA.