Research On Comprehensive Optimization Of Rudder Surface Structure Based On Dynamic Characteristics

Rudder surface structure is an inseparable part of the hypersonic aerocraft,whose stability is the key that determines the normal operation of an aerocraft.Rudder surface flutter,as a typical form of dynamic instability of the airfoil surface structure of hypersonic aerocraft.It shows that the structure is destroyed due to the aeroelastic coupling under a certain critical speed and phase relation.Therefore,it has important theoretical significance and wide application value the and research on the dynamic stability of the rudder surface structure.Introducing dynamic characteristics into structural design stage can avoid the repeated iterations of the dynamic analysis during the later period,meanwhile,it can also shorten the design cycle.In this paper,based on the dynamic characteristics analysis of the aeroelastic coupling,it carries out the comprehensive optimization research on the topology and size of the rudder surface structure in allusion to the triangular full-motion rudder of hypersonic aerocraft.The main contents include:(1)It has systematically researched on the dynamic analysis method of the aeroelastic system and carried out the dynamics analysis of the typical rudder surface structure.According to the aeroelastic dynamic equation of flutter analysis,it performs a dynamic analysis of the initial configuration of the rudder surface structure under the aeroelastic coupling,after which it obtains the dynamic characteristics analysis result of the rudder surface structure.Based on which,it changes the configuration component size,and analyzes and researches on the influence of different component size changes on the flutter characteristics of the rudder surface structure.(2)It adopts the variable density method to study the multi-condition and multi-constrained topology optimization of rudder surface structure under typical working conditions.According to the aerodynamic appearance of the triangular rudder surface structure,it establishes the topological optimization finite element model of the rudder surface structure.Meanwhile,combining with the aerodynamic forces under three typical hypersonic flight conditions to carry out the parametric equivalent conversion from aerodynamic network point to the structural node by adopting load equivalent method.Adopting the variable density topology optimization method to carry out the research on the structural layout configuration optimization under multiple operating conditions and constraints.It has analyzed the effects of aerodynamics and various constraints on the structural configuration,and obtained the optimal force transferring path and topology structure.(3)It adopts the genetic algorithm to carry out the research on the optimization of aeroelastic topological configuration size.Based on the topological configuration of the rudder surface structure,it establishes the finite element model and two size optimization models:a static optimization model without considering aeroelastic constraints and a dynamic optimization model considering aeroelastic constraints.And it adopts the parallel genetic algorithm to optimize the design.It analyzes the relationship curves between flight speed,damping and vibration frequency of the two optimization schemes.The optimization results of which show that considering the aeroelastic constraints during the structural optimization design can obtain the ideal configuration of the rudder surface structure that meets the lightweight,static and dynamic characteristics.