A PARAMETRIC STUDY OF OPTIMUM DESIGNS FOR BENCHMARK STIFFENED WING PANELS

Results are presented for the most heavily and lightly loaded of eight benchmark stiffened laminated wing panels defined from a Dornier wing by a GARTEUR (Group for Aeronautical Research and Technology in Europ e) working party. These benchmark panels had three identical and equal ly spaced blade stiffeners. The results were chosen to help designers to understand many important aspects of the choice of design variables , and of the effects of changing the sophistication of modelling and t heory used, for a wide range of wing panels. The percentage changes of (global) optimum mass are presented, along with the final values of t he design variables. Some examples of mass histories and of (rejected) local optimum masses are also given. The principal design variables a re skin and blade ply thicknesses and blade height. Additional factors considered include the effects of adding flanges to the blades whose plies either matched those of the blades or were allowed to vary indep endently, varying the number of stiffeners, allowing the stiffeners to differ from each other, varying stiffener spacing, varying some ply a ngles, including the stiffening effect of adjacent spars, including th e effects of continuity with laterally adjacent panels, including thro ugh thickness shear deformation in the panel analysis and analysing th e panel with its true skewed shape rather than approximating it as rec tangular in plan.