Analysis Of Out-of-Plane Deformation Of Anti-Tetra-Chiral Honeycomb

The aerodynamic shape of the aircraft inlet and radome should be changed actively according to different external flight environment and the requirements of its own combat mission,so as to achieve the optimal comprehensive performance of the aircraft.Take the intake port as an example.In different flight conditions,different intake volumes need to be provided.Meanwhile,hyperbolic bulge configuration is adopted in the inlet and radome,which is the result of the special deformation of negative Poisson’s ratio structural plane.The saddle surface will be formed after bending outside the positive Poisson’s ratio structural plane,which does not conform to streamline and has a small volume.After bending,the negative Poisson’s ratio structure will form a quasi-spherical shape(hyperbolic type)with streamline shape and large volume.The typical negative Poisson’s ratio structure mostly belongs to honeycomb structure.Honeycomb structure is derived from the common life honeycomb topological structure covering a two-dimensional plane,because of its special geometric configuration,makes the honeycomb structure has a strong bearing capacity and the optimal specific strength,specific stiffness,in military and civil applications.Honeycomb structure in a variety of forms,but one type of chiral cellular have strong design,and easier to achieve a larger surface deformation,therefore,the object of this study is with negative Poisson’s ratio of chiral features honeycomb type,namely,anti-tetra-chiral honeycomb,analysis of the in-plane mechanical properties and deformation of the outer performance,and by uniform honeycomb structure,non-uniform anti-tetra-chiral honeycomb was designed and analyzed.The equivalent elastic modulus,equivalent Poisson’s ratio and equivalent shear modulus of anti-tetra-chiral honeycomb in plane were deduced by using the energy principle of material mechanics and Castigliano’s second theorem.By using ABAQUS simulation software,the correctness of the theory is verified through simulation analysis.In this paper,the out-of-plane deformation of orthonormal non-uniform anti-tetra-chiral honeycomb is analyzed,and the theoretical formulas for large deflection of orthonormal anisotropic plates are derived from the theory of small deflection of elastic thin plates,small deflection of anisotropic plates and large deflection of thin plates.By means of numerical analysis,the out-of-plane deformation properties of quadrature anti-tetra-chiral honeycomb were analyzed,and the deflection curve was obtained by fitting.The result was a quaternary function of position,and the relationship between the deflection function and the coefficient of different rib lengths was also obtained.By numerical method,the non-uniform anti-tetra-chiral honeycomb outside surface deformation were analyzed,and through the rib change long form to change the structure of honeycomb cell,in order to get change of honeycomb cellular structure consisting of a thin plate with bending deformation under certain constraint and load deflection curve,the relationship between cellular surface from fitting outer bending deformation curve remains after the location of the four functions,The relationship between the deflection curve function and the changing rib length is obtained.