Survivability Modeling and Validation in Complex Rib-skin Structures

This paper presents a coordinated effort to model, test and validate the structural response of complex aerospace rib-skin structures in both undamaged and damaged configurations. Coordinated experimental and finite element model results are presented for cylindrical rib-skin structures each approximately nine foot long, and thirty inches in diameter. The test articles considered are of riveted aluminum construction and include internal structural components including bulkheads and complex stiffeners. Experimental reproduction of the highly idealized loading conditions used in the finite element models required the development of a custom loading rig that is described in detail. In summary, the finite element models were found to predict the structural stiffness of both the damaged and undamaged structures well for small deflections and strains. However, structural failure was not well predicted because large deflections and nonlinear material behavior were intentionally not modeled for simplicity.