Structural Design And Deformation Characteristics Analysis Of Morphing Wing Truss Structure

With the improvement of various requirements for flexibility,maneuverability and multi-tasking adaptability of aircraft,researchers have turned their attention to the study of deformable aircraft.The variant aircraft can continually change the shape and attitude of the wing according to different missions and environments,thereby enabling the aircraft to maintain optimal flight performance in different environments.For the study of deformable wings,some research institutions in Europe and the United States have started relatively early,and domestic research projects have been carried out in recent years.From the research progress at home and abroad,the research on the morphing wing mainly focuses on large-scale deformation in one direction such as variable swept,variable camber,and variable span,which has limited improvement on the flight performance of the aircraft.Therefore,it is meaningful to study the deformable wing that can achieve multi-dimensional deformation.In this paper,aiming at the problems of single deformation and complicated structure and bulkiness in the research of morphing wing,a morphing wing truss structure based on deformable unit can be designed to realize its curvature deformation in span direction and torsional deformation.Through the analysis of the structural form of the deformable corrugated sandwich panel and the deformation principle of the animal's spine,the design idea of the morphing wing structure is proposed: the large deformation of the entire wing is achieved by the accumulation of small deformations in the deformable truss unit.By comparing the deformation resistance and the specific stiffness of the structure,the structural form of the truss surface is preferred;according to the stiffness matching relationship,the relationship between the thickness of the thin plate and the size parameters of the truss members is obtained;according to the lightweight design requirements,the dimensional parameters of the deformable truss unit components are solved.For the two deformation forms of the morphing wing,the deformation principle and deformation law are studied respectively.According to the deformation principle of the beam,the curvature deformation in span direction is analyzed,and the derived equations are numerically solved using the Runge-Kutta method,the relationship between the bending deformation angle and the driving displacement and driving force is obtained,and the finite element simulation is carried out;the torsional deformation of the deformable truss unit is analyzed by the deformation influence coefficient method,the finite element software is used to solve the parameters such as the deformation influence coefficient matrix,and then the maximum torsional deformation angle of the morphing wing is solved.Considering the stiffness and stability requirements of the morphing wing structure,static analysis and dynamic analysis were carried out.The influence of the thin plate structure on the overall stiffness of the morphing wing is analyzed;the load capacity of the morphing wing was studied;the effects of unequal cross-section design on structural stiffness and strength are analyzed;and the modal of the morphing wing structure and its influencing factors are analyzed.The prototype of the morphing wing based on the deformable truss unit was designed and developed.And the bending deformation and torsional deformation test and load test were carried out to verify the deformation ability,load capacity and structural rigidity of the morphing wing.