| Composites for aircraft structures have important significance to weight reduction,As a significant component of aircraft,composite laminates have been widely used,and the optimum design method for layups of composite laminates is concerned increasingly in aviation realm.The design variables for layups of composite laminates mainly refer to: number of plies,ply percentage,and stacking sequence.In the process of optimum design,in order to make full use of the material and reduce the weight of structure,different parts of the composite laminates have different numbers of plies.at the same time,to improve structural integrity,ply blending should be ensured.In addition,for further improving buckling load,it is necessary to optimize the stacking sequence.In this paper,several kinds of typical optimum design methods and the theory of them have been analyzed and summarized.On the basis of mechanics and design principles of composite structures,a two-grade optimum design method for layups of composite laminates is proposed,with the help of some reliable optimizations,finite element software,and optimum design systems.Firstly the number of plies for each kind of angle in different parts of the composite laminates is optimized by the method called Conservative Discrete Design,in which the object is to find the most optimal structural weight.Secondly the Shared Layers Blending process is applied to organize several sets of shared layers,which can satisfy the global blending requirement.Then for further improving buckling load,the job of optimizing stacking sequence should be done,which can be solved by adjust the angle of every single layer by employing MIGA.In this paper,as an example,a structure of composite laminates is optimized,the results show that the proposed method has good efficiency.Then optimization design for the layups of composite laminates in a wing structure has been done,which further verify the method is suitable for more complicated problems. |
PDF Full Text Request