Adaptive Composite Structure Using Shape Memory Alloys

Patent metadata

Field	Value
Publication number	US-2016016355-A1
Application number	US-201414332412-A
Country	US
Kind code	A1
Filing date	Jul 16, 2014
Priority date	Jul 16, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

Systems and processes that integrate thermoplastic and shape memory alloy materials to form an adaptive composite structure capable of changing its shape. For example, the adaptive composite structure may be designed to serve as a multifunctional adaptive wing flight control surface. Other applications for such adaptive composite structures include in variable area fan nozzles, winglets, fairings, elevators, rudders, or other aircraft components having an aerodynamic surface whose shape is preferably controllable. The material systems can be integrated by means of overbraiding (interwoven) with tows of both thermoplastic and shape memory alloy materials or separate layers of each material can be consolidated (e.g., using induction heating) to make a flight control surface that does not require separate actuation.

First claim

1 . A pre-form comprising tows made of thermoplastic material interwoven with tapes or wires made of shape memory alloy.

2 . A system comprising a mandrel having an exterior surface and a pre-form in contact with said exterior surface and supported by said mandrel, wherein said pre-form comprises thermoplastic material and shape memory alloy.

3 . The system as recited in claim 2 , wherein said pre-form comprises tows made of thermoplastic material interwoven with tapes or wires made of shape memory alloy.

4 . The system as recited in claim 2 , wherein said pre-form comprises a first layer comprising shape memory alloy and a second layer comprising thermoplastic material without shape memory alloy, said first layer being disposed between said exterior surface of said mandrel and said second layer.

5 . The system as recited in claim 4 , wherein the shape memory alloy of said first layer is in the form of a continuous sheet or a multiplicity of tapes or wires.

6 . The system as recited in claim 4 , wherein said first layer comprises tows made of thermoplastic material interwoven with tapes or wires made of shape memory alloy.

7 . An aerodynamic device comprising first and second skins, each of said first and second skins comprising shape memory alloy and thermoplastic material.

8 . The aerodynamic device as recited in claim 7 , wherein said first skin comprises thermoplastic material and tapes or wires made of shape memory alloy material embedded in said thermoplastic material.

9 . The aerodynamic device as recited in claim 7 , wherein said first skin is a lamination comprising an inner layer comprising shape memory alloy and an outer layer comprising thermoplastic material without shape memory alloy, said inner layer being disposed inside said outer layer.

10 . The aerodynamic device as recited in claim 9 , wherein said inner layer comprises thermoplastic material and tapes or wires made of shape memory alloy at least partly embedded in the thermoplastic material of said inner layer.

11 . The aerodynamic device as recited in claim 7 , further comprising a first heating blanket thermally coupled to the shape memory alloy of said first skin and a second heating blanket thermally coupled to the shape memory alloy of said second skin.

12 . The aerodynamic device as recited in claim 7 , wherein the shape memory alloy of said first skin comprises a first multiplicity of wires and the shape memory alloy of said second skin comprises a second multiplicity of wires, further comprising a first electrical conductor electrically connected to respective ends of said first multiplicity of wires and a second electrical conductor electrically connected respective ends of said second multiplicity of wires.

13 . The aerodynamic device as recited in claim 7 , further comprising an induction coil and a smart susceptor thermally coupled to the shape memory alloy of said first skin, wherein said smart susceptor is disposed relative to said induction coil such that eddy currents will be induced in said smart susceptor when said induction coil is activated to generate an alternating magnetic field.

14 . The aerodynamic device as recited in claim 7 , at least some of the shape memory alloy of said first skin and at least some of the shape memory alloy of said second skin has been trained to deform in a specified manner in response to being heated.

15 . A method for fabricating a composite structure comprising:
overbraiding a heat-expandable mandrel with tows of thermoplastic material and tapes or wires made of shape memory alloy; placing the overbraided mandrel between first and second susceptors disposed between first and second tooling dies of an induction heating workcell; energizing one or more induction coils of the induction heating workcell to produce alternating magnetic fields which cause the first and second susceptors to produce heat, which heat in turn melts the thermoplastic material, softens the shape memory alloy, and expands the mandrel; de-energizing the induction coils of the induction heating workcell after the thermoplastic material has been consolidated to a desired degree and a composite structure has been formed; removing the mandrel and composite structure from the induction heating workcell; and separating the mandrel from the composite structure.

16 . The method as recited in claim 15 , further comprising training at least some of the shape memory alloy incorporated in the composite structure.

17 . The method as recited in claim 15 , wherein the mandrel is made of soluble material and separating the mandrel from the composite structure comprises solubilizing the soluble material of the mandrel.

18 . A method for fabricating a composite structure comprising:
placing a pre-form around and in contact with an exterior surface of a heat-expandable mandrel, wherein the pre-form comprises thermoplastic material and shape memory alloy; placing the mandrel and pre-form between first and second susceptors disposed between first and second tooling dies of an induction heating workcell; energizing one or more induction coils of the induction heating workcell to produce alternating magnetic fields which cause the first and second susceptors to produce heat, which heat in turn melts the thermoplastic material, softens the shape memory alloy, and expands the mandrel; de-energizing the induction coils of the induction heating workcell after the thermoplastic material has been consolidated to a desired degree and a composite structure has been formed; removing the mandrel and composite structure from the induction heating workcell; and separating the mandrel from the composite structure.

19 . The method as recited in claim 18 , wherein the pre-form comprises tows made of thermoplastic material interwoven with tapes or wires made of shape memory alloy.

20 . The method as recited in claim 18 , wherein the pre-form comprises a first layer comprising shape memory alloy and a second layer comprising thermoplastic material without shape memory alloy, the first layer being disposed between the exterior surface of the mandrel and the second layer.

Assignees

• Boeing Co

Inventors

• Marcoe Jeffery L
• Apdalhaliem Sahrudine
• Shome Moushumi

Classifications

• F03G7/06143

  Wires · CPC title

• F03G7/066

  Actuator control or monitoring · CPC title

• F03G7/06147

  Magnetic shape memory alloys, e.g. ferro-magnetic alloys · CPC title

• B29K2071/00

  Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material · CPC title

• H05K1/165

  incorporating printed inductors · CPC title