Airbus Defence and Space

COMPONENTS, ENGINEERING TOOLS AND SERVICES

Shape memory alloy deployment hinge

Shape memory alloys exhibit several thermo-mechanical properties, due to a solid phase transformation under thermal or mechanical specific conditions. SMA structures have two stable solid phases, the cold one and the hot one. Among various SMA properties, the one way memory effect has been selected for its maturity andstrain capability. This effect requires aneducation phase which associates two different shapes to the two material solid phases. When heated, the SMA will provide a mechanical work to go from the cold to the hot shape. For the one way effect, the SMA may be cooled down while applying an external stress to recover its previous cold shape.

Features / technical details

MAIN DESIGN FEATURES The SMA motorized cell and deployment hinge can be sized to meet a wide variety of needs in terms of resistive torque (up to 20 Nm) environment temperatures (up to 100°C) and kinematics requirements. Typical data corresponding to two particular versions of the motorised cell are presented in the following table:

Performances Max deployment angle - Total - Reproductibility

SMA-MC1

> 185 deg > 215 deg

SMA-MC2

+/-5 deg +/-5 deg

Available motor torque > 2 N.m > 2 N.m
Heating power 2 < P < 10 W 3 < P < 10 W
Heating element type Thermocoax Thermocoax
Typical deployment duration (Heating power : 4W) 4 minutes 5 minutes
  note: deployment time can be adapted with the heating power profile
SMA temperature - Start (under 2 N.m resistive torque) - end of deployment > 70 °C > 100 °C 150 °C 210 °C
Number of cycle (motorisation + recovering) > 50 > 50
Cold shape recovering 2 N.m torque 3 N.m
Cell characteristics - Mass 120 g 150 g
  • Diameter
50 mm 50 mm
  • Length
120 mm 230 mm
  • Mounting interfaces
4xM4 screws 4xM4 screws