The Design and Testing of Buckling Monocoque Seating Structures for Aircraft

The introduction of FAR23.562 to the Federal Aviation Regulations has necessitated the design and testing of aircraft seats with energy absorbing characteristics to minimize pelvic loads experienced when the seat environment is subject to specified acceleration pulses. Aircraft seat designers have applied various techniques to facilitate this energy absorption. Generally these techniques come at the expense of ease of manufacture and durability. This paper describes the development and testing of seating structures fabricated in a simple and easily reproducible form from sheet aluminium. The design employs both compressive buckling and plastic tensile deformation of the aluminium panels in the seat pan as the means of energy absorption. As the post buckled deflections required to provide sufficient seat stroke are large, the design process does not lend itself to simple theoretical analysis. The experimental development of a simple seat pan design through representative testing to FAR23.562 is described in this paper. Additionally, results of the dynamic load tests are compared with a static load test result and non-linear finite element analyses for each of the designs.