Stability Analysis And Global Structure Design Of Composite Rear Pressure Bulkhead

With the understanding of composite materials deepen and deepen, more and more composite materials have been used in the modern civil aircraft design. The traditional metal rear pressure bulkhead is gradually replaced by composite materials design. In order to further enhance the performance of the composite rear pressure bulkhead design, it is very necessary to make the well study. This paper is mainly concerned with the global structure design and the factor which could influence the bulking stability of the composite rear pressure bulkhead.Firstly, the global design solution is determined. Based on it, the software MSC.Patran/Nastran is in the use to analyze the composite rear pressure bulkhead finite element model. The result is checked by Hoffman failure criteria and the maximum allowable strain failure criteria.A practical method of equivalence for hat-type composite foam stiffener is put forward. Finite element numerical simulation method is adopted to make the mechanics analysis of the hat-type composite foam stiffener. In the case of the axial stiffness and the bending stiffness to be equal,the hat-type composite foam stiffener was simulated by a one-dimensional isotropic solid rectangular solid beam according to the stiffness equivalence theory and the result is also checked by the calculation.Finally, the bulking stability of the composite rear pressure bulkhead is investigated. The structure hole, the skin thickness of the ball, the ball vector high stiffener arrangement and the stiffener height which could influence the stability of the composite rear pressure bulkhead had been separately analyzed by finite element calculation and the result would be useful for the structure designing and application for the future.