Optimal Design Of Horizontal Stabilizer For A High-range Wide Body Airplane

Aerospace design bureaus all over the world face a significant problem in the optimal design using composite materials.Old design methods have shown that they are applicable for metal structures mostly and cannot be applied for composites.Thus,this study aims to develop new approaches for aircraft design using composite materials.The new approaches are shown on a specific principal structural element such as horizontal stabilizer.The main research questions are what features should be considered to make a proper design and be confident that the composite structure is not overweighed and which method should be taken to make an optimal design.Based on a review of the literature,classical plate theory for laminates,beam theory and finite element method were taken as a basement to develop a brand new design method for composite materials.The theories mentioned previously were combined together in the one design method.Their advantages were allowed to define magnitude of shear flows in the horizontal stabilizer and find out the quantity of composite layers required.This method was implemented into MATLAB as a script.Finite element method was used as an independent numerical and iterative design method.The method was implemented as a model in the ABAQUS software.Finite element model provided a comparison of the results obtained by analytical approach.Analysis of resultant stresses and other related parameters demonstrated that the method based on classical plate theories for laminates and the beam theory are applicable for design parts made of composite materials.The finite element model of the horizontal stabilizer under static load case has shown roughly the same stresses in the whole structure.It means that the part has reached the optimal state.In conclusion,the research has indicated that presented design methods are worth to use them during design of aircraft parts such as horizontal stabilizer.However,the combined method and finite element method have pros and cons.On the one hand,the first mentioned method is faster.It is more useful for preliminary design.On the other hand,the mathematical model is oversimplified and cannot give a detailed stress distribution as a fine finite element model.Though,building a finite element model is time-consuming.Thus,this method is better to use during detailed design stage.