Design And Analysis Of Honeycomb Core Of Flexible Wing Skin

The main role of the flexible skin is to maintain the aircraft’s aerodynamic shape, adapt the changes of the wings and bear and pass the aerodynamic loads to wing skeleton, so that the aircraft has a good aerodynamic performance. Compared to fixed-wing of traditions aircraft, the adaptive variable-body aircraft need higher bearing capacity in the direction of out plane, good in-plane deformation properties, light weight and good vibration resistance used to flexible skin support. Since the topological shape of the characterization honeycomb unit is an important factor affecting the performance of the flexible skin, so based on cellular unit carried out a detailed study. Through cutting edge method to get rid of the traditional honeycomb structure, we proposed a novel honeycomb structure, designed and manufactured specimen, made the corresponding study of theoretical and experimental.Refer to Gibson and Ashby’s equivalent method, we deduce the In-plane elastic parameters of the improved honeycomb structure through energy method, study the equivalent shear modulus based on the minimum potential energy principle and minimum complementary energy principle. All these give the reference for the study the relationship between the geometric parameters and mechanical property. Then we use MATLAB conduct numeric analysis for the in-plane mechanical property of the honeycomb structure. We analyze different parameters how to influence the in-plane deformation performance through non-dimensionalizing the parameters of honeycomb unit. Research shows that the introduction of basis cell wall and basic cell wall angle improves the in-plane deformation performance of the structure, setting the theoretical path for multi-objective optimization of honeycomb unit structure.Modeling the inherent frequency of the honeycomb unit structure based on response surface method. We choose orthogonal experiment designing method to design space sample points, then use ANSYS to do modal analysis to find the response surface value. And then we make sure the approximate expression between the first-order modal inherent frequency of honeycomb unit structure and honeycomb unit geometric dimensions, together with verifying the model’s reliability.We improve the particle swarm optimization algorithm based on simulated annealing method, avoiding the defect of local optimization point of particle swarm optimization, and apply it to honeycomb unit structure’s multi-objective optimization successfully. Machining several different honeycomb test-pieces, reference to national test standards conduct the tensile test of inner surface, the compression test and three-point bending test, and make a comparison between the new and traditional structure. The test results show that the new structure in line with the flexible skin deformation characteristic requirements.