Study On Dynamics And Aeroelastic Stability Of Rigid-flexible Coupled System Of Double Articulated Folding Wings

In order to meet the requirements of tactical missile seeking miniaturized launcher,convenient for storage,transportation and launching,it has become a trend to launch missile by using box(barrel)launching technology,which saves the storage and transportation space of ammunition and improves the combat capability of weapon system.The missile wings that are launched by box(barrel)are defined as folded wings because they fold before launching and quickly unfold after launching.The deployable performance parameters of the foldable wing are the key factors in the design of the foldable wing.At present,the open research on missile folding wing deployable mechanism is all one fold,when the wing spread is large,it needs to be folded several times to meet the launch requirements of modern box(barrel)missile.Due to the rotation of the folding wing on exactly the movement for a wide range of movement of the structural dynamic behavior,in a complex environment with time-varying structure under the action of force,make the structure dynamic characteristics and aerodynamic characteristics are significant change,lead to double joints folding wing aeroelasticity problem is more complex than a folding wing or fixed wing,Therefore,the study on the aeroelasticity of double-jointed folding wings is not only of great academic significance,but also of practical engineering value.In the field of missile structure technology at home and abroad,few literatures study the rigid-flexible coupling dynamics modeling process of double-joint folding wings.Therefore,this paper tries to start from the rigid-flexible coupling dynamic modeling theory based on the rectangular thin plate with large-scale motion,and extend it to the fixed-axis rotation and unfolding action of the folding wing to calculate the dynamic response problem during the unfolding process of the folding wing,and Based on the coupling relationship between the multi-body dynamics model and the aerodynamic model,an aeroelastic model of the structure of the folded wing system is established,and the influence of the aeroelastic properties during the unfolding process is studied.So this subject adopts the method of combining theoretical analysis,numerical simulation and experimental research to study the kinematic characteristics and aerodynamic characteristics of the folding wing.for reference.The main work and achievements of the thesis are as follows:(1)A simplified two-section longitudinal folding wing structure model is proposed.The hybrid coordinate modeling method was used to describe the configuration of any point on the structural element.The displacement field was represented by elongation variable and Cartesian coordinate,and the displacement function of the element was derived based on the motion state of elastic deformation.Blade discrete multiple sub structure,and through the C-B method to establish the dynamic model of substructure in the modal coordinates and orthogonalization branch of substructure modal,and delete the repeated six rigid motion mode,undamped substructure dynamics equation is obtained,finally the multi-rigid-body structure coupled together with more supple structure,A rigid-flexible coupling multi-body dynamic model of a folding-wing system is established.(2)With double joint folding wing multi-body time-varying system as the research object,through to its large range of rigid body motion and structure of inertia coupling between deformation of flexible numerical simulation,this topic proposed is verified modeling theory can be applied to a good folding wing of the coupled system dynamics analysis,to ensure the convergence model has good unit,The problem of divergence of analysis results of zero-order approximation model is avoided,which indicates that the modeling theory of this topic is applicable and can lay a certain foundation for the rigid-flexible coupling dynamics stylized research of complex folding wing system.(3)An aerodynamic reduced-order modeling method is proposed,which uses a combination of dipole grid method,genetic optimization algorithm and spline interpolation technology to establish a time-domain aerodynamic model of the structure of the folding wing system,and uses the Kriging proxy model technology.The time-domain aerodynamic surrogate model in the time-varying system is calculated,and the multi-body dynamic model and the aerodynamic surrogate model are coupled and solved to establish the aeroelastic model of the double-joint folding wing during the unfolding process.The unsteady aerodynamic action caused by the two situations of the flexible coupling system is analyzed for aeroelastic stability.The analysis results show that the instability is caused by the quadratic term of velocity in the multi-flexible body dynamic model.(4)The centroid displacement equation is derived according to the synchronous expansion law of folding wing,and the influence of centroid position change on its aerodynamic performance is analyzed.The research results can provide theoretical support for the structural design of folding wing and its kinematic geometric parameters.