Cost optimization of composite aircraft structures including variable laminate qualities

Abstract

Composite structures can lower the weight of an airliner significantly. The increased production cost, however, requires the application of costeffective design strategies in which cost, weight and the desired laminate quality are taken into account. This paper proposes an optimization framework for composite aircraft structures that minimizes the direct operating cost on a part level. In addition to previous models, a nondestructive testing model is implemented that calculates design allowables of a laminate based on ultrasonic scan parameters. In a case study, the effect of the laminate quality on the direct operating cost is discussed. It is investigated how the permissible flaw size and therefore the scan pitch of a composite laminate can influence the optimal solution in terms of cost and weight; thus, the manufacturing cost, the non-destructive testing cost and the weight of a component can be balanced by optimizing the laminate quality in an early design phase.

Cost/weight optimization of composite prepreg structures for best draping strategy

“…Examples are stiffened panels, where the stringer shape and stringer pitch is responsible for the cost/weight balance of the overall part, see Curran et al [13] and Kaufmann et al [15,16].…”

“…Otherwise, the choice of solver was arbitrary. For a detailed description of the optimization framework it is referred to Kaufmann et al [15][16][17].…”

“…Despite the higher computational effort, we believe that the use of ABAQUS/CAE provides greater flexibility in terms of geometry and load cases, especially when dealing with composite structures. It was decided not to include the NDT module described in Kaufmann et al [16]. A solver was chosen that would process the output of these models, not be too sensitive to disturbances in the form of non-smooth objective and constraint functions, and thus lead to a good convergence rate.…”

Design and commission of an experimental test rig to apply a full-scale pressure load on composite sandwich panels representative of an aircraft secondary structure

“…However, the reduction in weight comes at a cost premium, as the production methods associated with the manufacture of composite parts are very expensive [2,3]. A great deal of research [4][5][6][7] has been conducted on the optimisation of production methods for the use of composites in primary aircraft structure, however there is little work reported on secondary structure. This paper examines carbon fibre sandwich panels that are used as 'gap fillers' on the wing leading and trailing edges.…”

Material Selection for a Curved C-Spar Based on Cost Optimization

“…In earlier work it was shown how the optimal design of a skin/stringer structure was dependent on the weight penalty, see Kaufmann et al C [12]. Subsequently, the methodology was extended by implementation of non-destructive testing costs [13], the suboptimization of parameters for machining [14], and the optimization for best draping strategy [15].…”