Parametric design methodology for manufacturing of metallic and composite structures

A parametric, concurrent design methodology for manufacturing of metallic and composite structures is established. Often, during a new product development, designs prepared using the “Sequential” or “Waterfall” approach are rejected or require significant rework during manufacturing, as designers are not always versed with manufacturing principles. Similarly, manufacturers are not always versed in design principles resulting in designs that do not cater to the functional requirements. The goal of this study is to establish a methodology right from the scope to the detailed design for developing manufacturable structures using the “Concurrent Engineering” approach. Existing literature on “Design Optimization for Manufacturing” predominantly focus on single variable optimization problems geared towards conceptual designs. The designs developed through such optimization cater towards functional performance within a “Fixed Design Space” while not accounting for manufacturing or operational challenges. The methodology developed in this study enables “Design for Manufacturing” for “Detailed Designs” through selection of a conceptual design and subsequently optimizing the selected conceptual design for a set of functional parameters. An “Integrated Product Development” approach is used, whereby, the functional requirements are linked to both design and manufacturing variables and optimization is conducted in an “Augmented Design Space” which is not available when only considering design or manufacturing variables. Three case studies involving both “Conceptual” and “Detailed” designs have been used to illustrate the methodology presented. Case I documents the design of a Flight Control System Bracket. Case II illustrates the use of “2D” composite structures to fabricate a roll frame. Case III involves the development of a “3D” composite door for a light unpressurized aircraft. For each of the three case studies a separate development approach has been employed. Case I uses an analytical approach, Case II uses FEM while CASE III employs a hybrid approach comprising of both FEM and analytical techniques.