Research On Wing Stiffness Enhancement Technology Of Hypersonic Vehicle Based On SMA

Hypersonic flying equipment has the characteristics of precise strike,rapid response,and combat penetration,and has a wide combat space.It will assume important responsibilities in the future national defense construction.However,the aerodynamic heating problem has largely limited the development of hypersonic vehicles.In response to this problem,this paper takes hypersonic wing as the research object,and proposes a method of using shape memory alloy to enhance wing stiffness.First,the stiffness enhancement mechanism of shape memory alloys is analyzed.From the one-dimensional Brinson constitutive model of shape memory alloy,the restoring force formula during phase transformation is deduced;taking the composite beam as an example,the stiffness enhancement model of shape memory alloy is established,and the shape memory effect and elastic modulus of shape memory alloy are analyzed.The effect of change on the stiffness of composite beam structure.After comparing the effects,the shape memory effect is determined as a way to enhance the rigidity of the wing structure.Secondly,a simulation study of the wing characteristics under hypersonic speed is carried out.Combining with the characteristics of hypersonic flow,the wing three-dimensional structure parameterization design was carried out,the wing computational fluid dynamics model was established,and the influence of flight speed on the aerodynamic characteristics of the wing was studied through Fluent simulation;the unidirectional fluid-structure coupling method was adopted,The unidirectional fluid-structure coupling simulation model of the wing is established,and the influence of aerodynamic heating effect on the wing stiffness characteristics is studied through the fluid-structure coupling simulation.Aiming at the structure of the hypersonic delta wing,a compression rod type SMA stiffness-enhanced actuator is designed;the actuator's action effect under different Mach numbers is simulated and verified;the length of the actuator and the width of the rod are verified.The main configuration parameters of the two actuators were simulated and optimized;the layout of the actuators in the wing was simulated and optimized,and the results showed that the actuator was used to actuate the end of the wing,and the rigidity of the wing was affected.The enhancement effect is the best.Through actuator configuration parameters and layout optimization simulation,the best configuration parameters and layout plan of the actuator are obtained.Designed and processed the prototype of the wing principle.The electronic universal testing machine was used to load test the wing prototype.The actuator was controlled by heating the SMA sheet,and the pressure-deformation curve of the wing prototype at different test points before and after heating was compared.This verifies the effectiveness of the designed strut-type actuator on the rigidity of the delta wing structure under static load.