Shape and Layup Optimization of Laminated Composite Shells based on Integrated Framework of Modeling and Analysis

†Shape design and layup optimization of shell structure is implemented on a basis of integrated framework of geometric modeling and finite element analysis which is constructed on the geometrically exact shell theory. This shell theory enables more accurate and robust analysis for complicated shell structures, and it fits for the nature of B-splines function which is a popular modeling scheme in CAD field. Shape of laminated composite shells is optimized through genetic algorithm and sequential linear programming, because there are numerous optima for various configurations, constraints, and searching paths. Sequential adaptation of global and local optimization makes the process more efficient. Layup optimization is carried out by genetic algorithm for its discrete characteristics. I. Introduction HELL is a thin curved structural component, which is used to sustain loads with light weight structure, or to make large containing space. To fulfill this objective of the structure, laminated composite material is widely used for shell structure, because composite material has better performance in specific stiffness and specific strength than conventional metallic materials. These properties of composite shell make it prevail in the industry of automobile, aircraft, shipping, and architecture. Regardless of these benefits, composite shell structure has complexities in numerical analysis, so various and consecutive efforts to understand the mechanical behaviors of shell have been made in the fields computational mechanics and experimental tests. And especially shape optimization of shell structure is one of the state of the art technologies. For shape optimization of shell structures, three kind of research area need to be addressed, and connected with each other systematically. They are finite element analysis part for describing the behavior of shell structure, computer aided geometric modeling part for presenting modified position and geometric properties, and shape