TY - GEN
T1 - Feasible region of lamination parameters for optimization of variable angle tow (VAT) composite plates
AU - Wu, Zhangming
AU - Raju, Gangadharan
AU - Weaver, Paul M.
PY - 2013
Y1 - 2013
N2 - In structural optimization of laminated composites, the complexity of some design prob- lems can be significantly reduced by introducing lamination parameters as design variables. The value of each lamination parameter is not truly independent and instead are interlinked by a particular lamination (lay-up). Although the feasible region of 12 lamination param- eters has already been shown to be convex, the explicit relations between the parameters are generally unknown. In the design of variable angle tow (VAT) composite laminates, the lamination parameters vary as a function of x; y coordinates. The value of each lamination parameter continuously varies in a smooth manner and their constraints should be satisfied at all points. Consequently, accurate bounds for the feasible region of lamination parame- ters are necessary to describe the design constraints in the optimization of VAT laminates. This paper presents a set of explicit closed-form expressions to define the feasible region of two in-plane and two out-of-plane lamination parameters, which can be applied to the design of orthotropic VAT laminates. A preliminary buckling optimization of a square orthotropic VAT panel is presented using lamination parameters that are represented by a polynomial series. The distribution of lamination parameters are pointwise constrained by the closed-form nonlinear inequalities. The optimum results demonstrate the applicability of the presented expressions for lamination parameters in the design of VAT panels. Fi- nally, corresponding fibre angles distributions are generated from the optimal lamination parameters using a genetic algorithm (GA).
AB - In structural optimization of laminated composites, the complexity of some design prob- lems can be significantly reduced by introducing lamination parameters as design variables. The value of each lamination parameter is not truly independent and instead are interlinked by a particular lamination (lay-up). Although the feasible region of 12 lamination param- eters has already been shown to be convex, the explicit relations between the parameters are generally unknown. In the design of variable angle tow (VAT) composite laminates, the lamination parameters vary as a function of x; y coordinates. The value of each lamination parameter continuously varies in a smooth manner and their constraints should be satisfied at all points. Consequently, accurate bounds for the feasible region of lamination parame- ters are necessary to describe the design constraints in the optimization of VAT laminates. This paper presents a set of explicit closed-form expressions to define the feasible region of two in-plane and two out-of-plane lamination parameters, which can be applied to the design of orthotropic VAT laminates. A preliminary buckling optimization of a square orthotropic VAT panel is presented using lamination parameters that are represented by a polynomial series. The distribution of lamination parameters are pointwise constrained by the closed-form nonlinear inequalities. The optimum results demonstrate the applicability of the presented expressions for lamination parameters in the design of VAT panels. Fi- nally, corresponding fibre angles distributions are generated from the optimal lamination parameters using a genetic algorithm (GA).
UR - http://www.scopus.com/inward/record.url?scp=84881333655&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84881333655
SN - 9781624102233
T3 - Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
BT - 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
T2 - 54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference
Y2 - 8 April 2013 through 11 April 2013
ER -