Influence of composite wing elasticity parameters on structure weight

A new algorithm for a composite wing optimization procedure is presented, with account taken of constraints on structure elasticity characteristics. The optimal strength and stiffness parameters of the composite wing are determined by using the analytical beam model of the wing and the parametric finite element model of the airframe structure. At the first stage, the problem of weight optimization is solved by the classical beam model. The obtained optimal values of stiffness parameters are transferred to the data base of the FEM model. Additional constrains on the finite elements stiffness are based on these values. According to the calculations these constrains are active for the lateral parts of the wings. Then the classical problem of determining the optimal structure parameters is solved by the FEM model to satisfy minimum weight criteria. The use of this algorithm at the initial stage of designing allows us to substantialy reduce the time-consuming calculations and obtain the reliable estimates of the elasticity effect on the structure weight in terms of linear FEM models.