Abstract
The present paper shows a reliable and efficient optimization approach on a minimum weight design of laminated composites under a single in-plane loading. Layer orientation angles as well as layer thicknesses are used as design variables, and the optimization technique is based upon a mathematical programming method. Transformed design variables with respect to the layer orientation angles in the principal loading direction are introduced to reduce the nonlinearity between strength constraints and design variables. A technique is also proposed to delete the strength constraints of almost zero thickness layers.