Analysis of an internally pressurized orthogonally stiffened cylindrical shell with an asymmetrical section ring

摘要

The linear elastic response is determiend for an internally pressurized, long circular cylindrical shell stiffened on the inside by a regular arrangement of identical stringers and identifical rings. Periodicity of this configuration permits the analysis of a unit cell consisting of a portion of the shell wall centered over one stringer-ring joint. the stiffeners are modeled as discrete beams. The stringer is assumed to have a symmetrical cross section and the ring an asymmetric open section. Displacements are assumed as truncated Fourier Series plus simple terms in the axial coordinate to account for the closed-end pressure vessel effect. Equilibrium is imposed by virtual work. Point-wise displacement continuity between the shell and stiffeners is achieved by Lagrange multipliers which represent the interacting line load distributions between the stiffeners and the inside shell wall. A composite material crown panel typical of a large transport fuselage is used as numerical example. Structural models include effects of transverse shear deformations and warping deformation of the ring's cross section due to torsion. The interacting loads associated with the asymmetric response, and the out-of-plane bending moment and torque in the ring, are very sensitive to these structural modeling effects.