Design for Manufacturing Airframe Structures Optimization

Traditionally, in composite part design, stress analysis and design definition are frozen before the part definition is passed on to manufacturing. As a result problems inherent to manufacturing are unveiled late in the process, and design changes are expensive and often do not fit into the schedule. The aerospace industry is expressing needs for design optimization and design for manufacture with the aim of producing lighter, cheaper and more efficient components. The approach undertaken in CADFiber, the software suit developed by Coriolis Composites in France, is to capture in the CAD/CAM model, knowledge, constraints and design objectives for the optimization of the design. From an early stage of the design process, evaluation of the composites laminate properties is necessary for feeding the optimization loop. Gap density, fiber orientation, material isotropy, steering radius, bridging and manufacturing cycle time estimations are identified as the principal drivers leading to optimal design. Study of the effect of fiber placement singularities is proposed by Croft(1). The proposed framework aims to encapsulate stress, design and manufacture objectives in a common flexible environment, thus enabling the optimization process.