Research On Structure Size Multi-objective Optimization Of Negative Poisson’s Ratio Honeycomb Core

Compared with conventional aircraft, modern aircraft in flight, if you have an adaptive wing air can easily cope with various environmental changes. Initiative to adapt to changes in flight status and flight conditions, the wings can automatic bending, twisting, stretching and deformation such as variable sweep angle. Airworthiness of the aircraft in order to achieve optimal performance and mobility. With traditional manned aircraft wing rudder surface can be achieved relatively adaptive better mobility, greater load capacity, a smaller proportion of the whole and superior endurance. Modern intelligent adaptive changes in the structure of an aircraft wing shape not only need the appropriate drivers and the drive mechanism, the skin also needs a strong load capacity of the structure as a support. Wing skins currently widely used internationally and can not meet the load requirements of both large deformation and need to further improve its anti-vibration capability, has become the focus of new aircraft and focus research attention. The project based on National Natural Science Foundation Project (NO.51075380)"super-elastic skin structure deformation mechanism and optimization of design research," based on the honeycomb core structure is applied to study the structure of super-elastic skin has been growing attention.For a negative Poisson’s ratio of the structural characteristics of a hexagonal honeycomb core skins and structural defects of today, the honeycomb core structure to supple skin super-elastic design of the honeycomb core structure, which is expected to achieve deformation, structural rigidity and resistance to light vibration and other aspects of the whole voyage superb performance adaptive wing skin structure. The negative Poisson’s ratio hexagonal honeycomb cell structure as a core part of the super-elastic skin, and its structural performance as the primary research questions developed super-elastic skin.In this paper, a negative Poisson’s ratio hexagonal honeycomb core structure for the study of structural honeycomb core cell size parameters for multi-objective optimization. In order to improve honeycomb core structure capacity and to minimize vibration structural quality of research objectives, using classical mathematical model of response surface theory to establish a lower mode natural frequency honeycomb core structure approxim ate explicit expression; using a weighting factor method, the natural frequencies and multi-objective optimization problem of structural quality into a single objective optimization problem, and genetic algorithm optimization objectives. Specific examples show that the optimized structure parameters of honeycomb core natural frequencies greatly improved, reducing the structural mass corresponding to multi-objective honeycomb core cell structure is designed to optimize the size of the super-elastic skin supple honeycomb structure design provides a good basis.The main contents are as follows:First introduced an overview of the status of intelligent and adaptive deformable wing aircraft and study about nation and abroad, and several deformable skin a brief introduction, highlighting the research foundation and focus of negative Poisson’s ratio hexagons honeycomb cell structure, all the contents of this paper launched as a research object, lists the contents and framework laid paper studies the significance and status.Then, based on the response surface methodology honeycomb structure modeling natural frequency of response surface methodology relevant principles and techniques were clarified by response surface classical mathematical model to derive a mathematical model of response surface coefficient, thus the natural frequency of a mathematical model for the subsequent derivation foundation. And the mathematical model testing methods established by the response surface method; response surface method for testing the mathematical model used in the derivation process orthogonal experiment method, introduced and practical applications. The cellular unit modal simulation using finite element analysis, introduces the basic principles of the basic principles of the finite element method and finite element software ANS YS and basic operations. Using the finite element software ANSYS negative Poisson’s ratio hexagonal honeycomb core cell structures parametric modeling and simulation analysis by orthogonal experimental data obtained with a natural frequency values and derive honeycomb cell size parameters mathematical model with first-order natural frequency relations.Finally, using genetic algorithm method to solve honeycomb core cell structure size parameters for multi-objective optimization, optimization toolbox for less than classical genetic algorithm has been improved, the quality of the natural frequency of the mathematical model combines mathematical model for multi-objective optimization genetic algorithm based on MATLAB, has been very good optimization results, the natural frequency has been greatly improved, and the corresponding reduction in structural quality. The new honeycomb skin negative Poisson’s super-elastic design provides a good basis for the hexagon honeycomb cell structure size.