ON THE INFLUENCE OF INITIAL GEOMETRIC IMPERFECTIONS ON THE BUCKLING AND POSTBUCKLING BEHAVIOR OF FIBER-REINFORCED CYLINDRICAL SHELLS UNDER UNIFORM AXIAL COMPRESSION

Abstract : The effect of initial geometric imperfections on the buckling and postbuckling behavior of composite cylindrical shells subjected to uniform axial compression is studied in this report. The solution is obtained by employing von Karman-Donnell nonlinear strain-displacement relations and the principle of stationary potential energy. Numerical results are given for various fiber orientations in the three-layer shell consisting of either glass-epoxy or boron-epoxy composites, with different initial imperfections. Results indicate that the boron-epoxy composite shells are less imperfection sensitive than the glass-epoxy composite shells. Isotropic shells are found to be more imperfection sensitive than composite shells. It is noticed that the increase or decrease in the classical buckling load with change in fiber orientation is generally accompanied by a decrease or increase in imperfection sensitivity of the shell.