Development of a Numerical Modeling Approach for Buckling Analysis of Sandwich Composite Cylindrical Shells with Selected Results

The buckling response of geometrically perfect and imperfect cylindrical sandwich shells can be investigated using nonlinear finite element analyses with two-dimensional general-purpose shell elements. Such analyses are used in the NASA Engineering and Safety Center Shell Buckling Knockdown Factor Project, which has the goal of developing new analysis-based buckling design recommendations for select classes of sandwich composite cylindrical structures under uniaxial compressive load. As such, finite element models of sandwich composite cylinders were developed and analyses were performed to predict the buckling responses of geometrically perfect and imperfect sandwich composite cylinders. The development of the selected finite-element modeling approach for a sandwich composite cylinder is discussed. Buckling-response sensitivity of geometrically imperfect sandwich cylinders for various shell element types were investigated as part of this study. Preliminary results of geometric imperfections influence on buckling response of sandwich cylinders are also presented.