Disclosure of Invention
The invention aims to overcome the defects of weaker bearing capacity and the like in the prior art and provides a wing based on a bistable composite material, which has the advantages of high deformation speed, stable configuration, high specific stiffness and strong bearing capacity.
The invention provides a bistable composite material-based wing, which comprises a main body, a wing tip and a bistable deformation connecting section for connecting the main body and the wing tip;
The bistable deformation connecting section comprises a bistable composite material plate and a driving component, wherein the bistable deformation connecting section can perform bistable jump to change an included angle between the main body and the wingtip, the driving component is an SMA spring, and the stable jump of the bistable composite material plate is driven by the SMA spring to realize the integral bending of the bistable deformation connecting section, so that the angle of the wingtip is changed;
the bending of the bistable composite material plate is essentially steady jump of the bistable composite material, namely, the bistable composite material plate manufactured by an asymmetric layering mode can generate residual stress between layers and show specific deformation trend in different directions, the bistable composite material plate can be mainly deformed in a certain direction by applying load in the specific direction so as to obtain different stable configurations, the bending curvature of the bistable composite material plate is related to the mechanical property of the material, the thickness of the plate and the like, and the bistable composite material plate can be independently designed according to the bending angle generated by the required wing tip.
Further, the bistable deformation connection section further comprises a flexible skin, the flexible skin is arranged on the outer side of the bistable deformation connection section, and the SMA spring is arranged between the flexible skin and the bistable composite material plate. The flexible skin is corrugated to enhance the heat dissipation of the SMA spring and to enhance its deformability.
Further, the bistable deformation connecting section also comprises a honeycomb sandwich or a corrugated plate, and the bistable composite material plate is connected with the honeycomb sandwich or the corrugated plate through cementing. The deformation of the bistable composite material plate is not affected.
Further, a concave space for accommodating the bistable deformation connection section and a guide rail for pushing out and retracting the bistable deformation connection section are arranged inside the main body. The guide rail arranged in the concave space is a controllable feed amount guide rail controlled by a motor, and the bistable deformation connecting section can be retracted into the concave space according to the requirement. After retraction, the SMA spring and flexible skin will be in a compressed state.
Further, the device also comprises a heating power supply, wherein the heating power supply is arranged in the concave space.
Furthermore, the SMA spring is installed through a tension spring drag hook installed on the main body and the wing tip, and the tension spring drag hook is connected with a lead of the SMA heating loop.
Further, the bistable composite plate comprises bistable deformation segments for deformation and monostable mounting segments for two-sided mounting. Bistable composite plates with monostable mounting segments are one particular bistable composite arrangement. When laying, a plurality of continuous fiber layers are generally taken as a base layer, and the base layer is divided into a monostable installation section at two ends and a bistable deformation section in the middle according to design requirements. The fiber laying method of the bistable composite material plate can adopt an automatic wire laying technology.
Furthermore, the bistable deformation section is made of a long fiber reinforced composite material, the layering mode is an antisymmetric or asymmetric layering mode, the monostable mounting section is made of a long fiber reinforced composite material, and the layering mode is a unidirectional or symmetric layering mode.
Further, the monostable mounting section is rigidly connected with a guide rail and a wing tip arranged in the main body respectively, and the bistable deformation section is not directly connected with the main body or the wing tip.
Further, the SMA spring is a one-way or two-way shape memory alloy spring, and the SMA spring is installed along the expanding direction or the oblique direction of the bistable deformation connection section. In particular, reference may be made to the sweep angle of the body or to the generation of sufficient bending moments.
Compared with the prior art, the invention has the following advantages:
High deformation speed, stable configuration, high specific stiffness and strong bearing capacity. The bistable composite material plate manufactured by an asymmetric layering mode can generate residual stress between layers and show specific deformation trends in different directions, and the bistable composite material plate can be mainly deformed in a certain direction by applying load in the specific direction so as to obtain different stable configurations.
Detailed Description
The invention will now be described in detail with reference to the drawings and specific examples. Features such as a part model, a material name, a connection structure, a control method, an algorithm and the like which are not explicitly described in the technical scheme are all regarded as common technical features disclosed in the prior art.
Example 1
The embodiment provides a bistable composite material-based wing, as shown in figures 1, 2,3 and 4, comprising a main body 1, a wing tip 2 and a bistable deformation connecting section for connecting the main body 1 and the wing tip 2;
The bistable deformation connecting section comprises a bistable composite material plate 3 and a driving component, wherein the bistable deformation connecting section can perform bistable jump to change an included angle between the main body 1 and the wingtip 2, the driving component is an SMA spring 4, and the stable jump of the bistable composite material plate 3 is driven by the SMA spring 4 to realize the integral bending of the bistable deformation connecting section, so that the angle of the wingtip 2 is changed;
The bending of the bistable composite material plate 3 is essentially steady-state jump of the bistable composite material, namely, the bistable composite material plate manufactured by an asymmetric layering mode generates residual stress between layers and shows specific deformation trend in different directions, the bistable composite material plate can be mainly deformed in a certain direction by applying load in the specific direction so as to obtain different stable configurations, the bending curvature of the bistable composite material plate is related to the mechanical property of the material, the thickness of the plate and the like, and the bistable composite material plate can be independently designed according to the bending angle generated by the required wingtips 2.
In a specific embodiment, the bistable deformation connection segment further comprises a flexible skin 7, the flexible skin 7 is arranged on the outer side of the bistable deformation connection segment, and the SMA spring 4 is arranged between the flexible skin 7 and the bistable composite material plate 3. The flexible skin 7 is made corrugated to enhance the heat dissipation of the SMA spring 4 and to increase its deformability.
In a specific embodiment, the bistable deformation connection section further comprises a honeycomb sandwich 8 or a corrugated plate, and the bistable composite material plate 3 is connected with the honeycomb sandwich or the corrugated plate 8 through cementing. To the extent that the deformation of the bistable composite plate 3 is not affected.
In a specific embodiment, the main body 1 is internally provided with a concave space 5 for receiving the bistable deformation joint and a guide rail 6 for pushing out and retracting the bistable deformation joint. As shown in fig. 2, the guide rail 6 installed in the concave space 5 is a controllable feed amount guide rail controlled by a motor, and the bistable deformation connection section can be retracted into the concave space 5 as needed. After retraction, the SMA spring 4 and flexible skin 7 will be in a compressed state.
In a specific embodiment, the heating device further comprises a heating power supply 9, and the heating power supply 9 is arranged in the concave space 5.
In a specific embodiment, the SMA spring 4 is installed through a tension spring retractor 10 installed on the main body 1 and the wingtip 2, and the tension spring retractor 10 is connected with a wire of the SMA heating loop.
In a specific embodiment, the bistable composite plate 3 comprises bistable deformation segments 11 for deformation and monostable mounting segments 12 for two-sided mounting. As shown in fig. 5, the bistable composite plate 3 with the monostable mounting segments 12 is a special bistable composite arrangement. When laying, a plurality of continuous fiber layers are generally taken as a base layer, and the base layer is divided into a monostable mounting section 12 at two ends and a bistable deformation section 11 in the middle according to design requirements. The fibre laying method of the bistable composite board 3 may employ an automatic fibre laying technique.
In a specific embodiment, the bistable deformation segment 11 is made of long fiber reinforced composite material, the layering mode is antisymmetric or asymmetric layering, the monostable mounting segment 12 is made of long fiber reinforced composite material, and the layering mode is unidirectional or symmetric layering.
In a specific embodiment, when the bistable deformation segment 11 and the monostable mounting segment 12 do not perform bending jump, the geometry of the transverse cross section of the laminated plate is an arc or an airfoil arc.
In a specific embodiment, the monostable mounting section 12 is rigidly connected to the rail 6 and the wing tip 2, respectively, provided inside the body 1, and the bistable deformation section 11 is not directly connected to the body 1 or the wing tip 2.
In a specific embodiment, the SMA spring 4 is a single-pass or double-pass shape memory alloy spring, and the SMA spring 4 is mounted along the bistable deformation joint in a spanwise or oblique direction. In particular, reference may be made to the sweep angle of the body or to the generation of sufficient bending moments.
As shown in fig. 1 and 2, the number of bistable composite plates 3 is plural, and the dimensions of each bistable composite plate 3 are not equal, and the respective length of each plate can be determined according to the angle of the wing tip 2 after bending and the curvature of the bistable composite plate 3. While the dimensions of the guide rail 6 and the concave space 5 are such that the longest bistable composite plate 3 can be contained.
In the wing, for the connection of the main body 1 and the wingtip 2, the functions of all parts of the bistable deformation connection section are different, the rigidity and the bearing capacity of the whole structure are ensured by rigidly connecting the bistable composite material plate 3 and the honeycomb sandwich 8 with the guide rail 6 and the wingtip 2, the wingtip 2 is prevented from being separated, the SMA spring 4 is arranged on the outer side of the bistable composite material plate 3 and the honeycomb sandwich 8, the transmission of driving force is convenient, and the outermost side is coated with the flexible skin 7 for maintaining the aerodynamic shape of the wing, so that the flexible skin 7 does not need to be completely flexible and the stable deformation of the bistable composite material plate 3 is not influenced.
After the bistable deformation connection section is pushed out by the guide rail 6, as shown in fig. 3, the SMA spring 4 generates a tensile force to make the bistable composite plates 3 jump and bend, at this time, the honeycomb sandwich 8 and the flexible skin 7 bend together with the bistable composite plates 3, and the bistable composite plates 3 with longer dimensions push out the rest part contained in the concave space 5 through the guide rail 6 when bending occurs. And the guide rail 6 fixes the feeding amount by motor self-locking to keep the bistable deformation connection section in the pushed-out state.
The bending of the plurality of bistable composite plates 3 may take place simultaneously or there may be a short gap, so that eventually it may be in the second stable configuration simultaneously.
Wherein the main part of the SMA spring 4 is SMA (Shape Memory Alloy ), wherein SMA is a smart metal material with shape memory effect (Shape Memory Effect, SME for short) and super (pseudo) elasticity (Superelasticity/Pseudoelasticity, SE for short). When the SMA spring 4 is heated above the phase transition temperature, it drives the corresponding deformation of the structure or product. Wherein the SMA spring 4 is a Shape Memory Alloy (SMA) spring, i.e. when heated and excited, the SMA spring returns to its memorized pre-strained state, thereby interacting with the structure and causing it to deform. After the temperature is reduced, the device can be restored to the state before driving under the action of the structural restoring force.
As shown in fig. 4, the SMA spring 4 is connected between the main body 1 and the wingtip 2 through a spring hook 10 installed at the main body 1 and the wingtip 2, and is heated by a heating circuit, and a heating power supply 9 is installed inside the main body 1, so as not to affect the normal movement of the guide rail 6 and the bistable composite material plate 3. The main body 1 is grooved and the spring hook 10 is mounted in the groove, so that the SMA spring 4 is not excessively compressed when the guide rail is not pushed out. The number of SMA springs 4 may be one or more. In particular, by generating a sufficient bending moment.
A more efficient heating instrument such as an electromagnetic induction heating tube is used.
The SMA spring 4 is mounted in an air duct using a more efficient cooling method, such as by building an air circulation system between the body 1 and the wingtip 2, using air cooling.
The components not described in detail in this embodiment are all existing components that can be purchased in public channels.
The previous description of the embodiments is provided to facilitate a person of ordinary skill in the art in order to make and use the present invention. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.