Spar And Rib Structure Optimization Of Composite Solar UAV

As a clean energy unmanned aerial vehicle,solar drones has the characteristics of large aspect ratio,long battery life and high flying height.The overall use of ultra-light composite materials makes the structure lighter and better performance.Solar drones have special applications in both military and civilian fields,and have gradually become a research hotspot in the field of UAVs at home and abroad.Structural optimization as a commonly used technical method in engineering design,can usually optimize the overall structure of the aircraft to obtain better mechanical properties and a better layout scheme.In the case of meeting the design requirements of solar drones,the overall structural weight is reduced to obtain the best structural performance.In this paper,a composite solar drones with a ten-meter wing span is taken as the research object,combined with the finite element theory to carry out a static analysis of the entire wing,focusing on the application of structural optimization technology to optimize the design of the spar and rib components.At the same time,the optimal beam rib layout scheme is obtained to achieve the purpose of weight reduction.The main research contents are as follows:（1）First,analyze the design requirements and performance indicators of the solar UAV wing structure,and determine the structure form of thin skin,double spar and multi-rib in combination with the force transmission method,and perform computational fluid dynamics on the wing surface.In the analysis,the multi-point row method is used to convert the aerodynamic load of the wing into the structural point load of the finite element mesh,and the establishment of the finite element model of the wing is completed through the steps of model simplification and mesh division.（2）According to the structural finite element method,the static strength analysis of the wing finite element model was carried out in Abaqus,combined with the failure criteria of composite laminates,the wing was verified by viewing the stress,strain,deformation displacement and Cai-Wu coefficient cloud diagram of the results.The overall structure meets the design requirements under load,and the internal structural materials are reliable,so there is a lot of room for optimization.（3）By applying the genetic method to transfer Abaqus software on the Isight platform to carry out the hierarchical optimization research of the wing spar structure,firstly the first-level optimization of the section size and position of the wing spar,and on this basis,the second-level layer thickness and angle of the wing spar are carried out.In the synchronous optimization,the math models with the lowest mass as the optimization goal were established respectively,and the best solution was obtained based on the MIGA.Finally,the weight of the wing structure is effectively dropped,and the overall performance is improved,achieving the goal of structural optimization.（4）Based on the traditional variable density method,the rib structure is topologically optimized,and a topology optimization model with the maximum stiffness as the optimization goal and the unit volume as the limit is created,and the interior of the rib is reasonably designed according to the optimization results and actual manufacturing requirements.Reducing the position of the hole further reduces the structural weight of the solar drone while ensuring that the structural strength and rigidity meet the requirements.Finally,three-point bending was performed on the composite laminate sample.The experiment is carried out,and the forming process of the optimized wing is introduced.Through the hierarchical optimization design of the spar structure,the whole quality of the wing structure is dropped by 29.7%,and the topology optimization devise of the rib model is completed,the whole quality of the wing rib is dropped by 35.6%,and the final whole quality of the wing structure is dropped by 31.8%.The optimization effect is obvious.After the optimization,the structural stress,strain,deformation displacement,etc.all suffice the design demands,and the overall performance has been greatly improved,which shows that the optimization scheme used in this paper is feasible and effective,and provides certain guidance for the design and research of composite solar UAV reference value.