A Method Of Topology Optimization Based On Feature Constraints And Its Application

With the application of topology optimization technology in the field of aircraft structural analysis,the idea of aerodynamic-structural integrated design has become increasingly popular in aircraft design.In this paper,we have studied the application of topology optimization technology in aerodynamic-structural coupling design systematically.Firstly,by the means of introducing the feature modeling technology,an efficient algorithm for 3D topology optimization based on feature is developed,which is useful to solve the bottleneck problem of the topology optimization method in engineering application.In this algorithm,all kinds of features are formed into searchable shape features by feature modeling technology,and feature element models are established.Then we can find feature elements that meet the design requirements using feature matching techniques.The constraint factor and the pseudo-density of the element are initialized according to the preferred feature element.The optimization criterion method and independent mesh filtering technique are used to optimize the structural design domain by controlling the constraint factor.Secondly,in order to introduce the feature element model into the topology optimization process,the constraint factor is introduced to improve the variable density topology optimization method.And a new pseudo-density expression is established to participate in the cycle process of topology optimization.The accuracy and practicability of the improved topology optimization method are verified by programming with MATLAB and an example of cantilever beam.Finally,the above results are applied to the structural design of the wing,and a three-dimensional topology optimization method is developed to load aerodynamic loads directly on the airfoil surface of the wing.The structural topology optimization is carried out with the constraints and load conditions closer to the real project,and the aerodynamic-structural three-dimensional coupling design of the wing is realized.The difference of aerodynamic loads among different airfoils is considered in this method and the load sensitivity is also taken into account.The feasibility and effectiveness of the method are verified with an example.