Semi-analytical methods for rapid pre-dimensioning of launcher structures subjected to Booster load introduction

This paper describes a new analysis method for orthotropic cylindrical shell structures with arbitrary stiffness distribution. The structural model consists of ring frame elements, orthotropic membrane panels and longitudinal stiffeners (stringer). The element stiffness matrix of the orthotropic panel is based on the displacements functions of its boundary only. The boundary value problem is solved by developing the stresses in Taylor series and applying the principal of virtual work (virtual forces). By this way it is possible to have large elements able to describe stress peaks. The method is applied for Booster load introduction into launcher structures and reduces the number of degrees of freedom drastically, allowing rapid analyses necessary for parametric optimization in the pre-design phase. •The new method allows to model orthotropic cylindrical structures with a few elements.•The boundary value problem of the membrane element is solved semi-analytical.•The resulting element stiffness matrix is able to describe high order stress problems.•The new method was applied on Booster load introduction problems of launcher.•The new method needs significantly less degrees of freedom compared to the classical FE method.