Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: A method to join a first structure to a second structure comprises aligning a first hole in the first structure with a second hole in the second structure and inserting a fastener into the first hole and the second hole. The fastener comprises a shape memory alloy which was formed into a first shape having a diameter slightly larger than a diameter of the first hole and the second hole when the shape memory alloy was in an austenite state and reduced to a second shape having a diameter less than the diameter of the first hole and the second hole when the shape memory alloy was in a martensite state. The method further comprises heating the fastener above an austenite start transition temperature.

Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: In one embodiment a method to join a first structure to a second structure, comprises aligning a first hole in the first structure with a second hole in the second structure and inserting a fastener into the first hole and the second hole. The fastener comprises a shape memory alloy which was formed into a first shape having a diameter slightly larger than a diameter of the first hole and the second hole when the shape memory alloy was in an austenite state and reduced to a second shape having a diameter less than the diameter of the first hole and the second hole when the shape memory alloy was in a martensite state.

Abstract: In one embodiment a method to join a first structure to a second structure, comprises aligning a first hole in the first structure with a second hole in the second structure and inserting a fastener into the first hole and the second hole. The fastener comprises a shape memory alloy which was formed into a first shape having a diameter slightly larger than a diameter of the first hole and the second hole when the shape memory alloy was in an austenite state and reduced to a second shape having a diameter less than the diameter of the first hole and the second hole when the shape memory alloy was in a martensite state.

Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.