DESIGN OPTIMIZATION OF COMPOSITE PLATES - PART-II - STRUCTURAL OPTIMIZATION BY PLYDROP TAPERING

A preliminary design tool was developed to optimize structures such as beams and plates, with optional cutouts, subject to multiple loadsets and any boundary conditions. SUNSPOT provides with simple, tapered an d manufacturable layups.Sublaminates, made of multiple plies at variou s orientations, combining one or more materials, are repeated or dropp ed in different zones of the structure, yielding the plydrops taper wh ile ensuring physical continuity of the fibers in all composite layers . The orientation and thickness of each ply group in this reference su blaminate as well as its number of repetitions in the zones across the structure, are optimized using the Nelder-Mead algorithm in conjuncti on with parametric SAMCEF Finite Element Analyses, all integrated with in SUNSPOT. The optimization objective is minimum weight for first ply failure strength. Maximum displacement constraints and economical man ufacturing can be enforced additionally. Therefore, extended Tsai-Wu s trength failure criteria were derived; new stiffness control criteria and a manufacturing complexity index were developed [1,2].