Because the ideal “rigid joint” and “hinged joint” are inexistent, the stiffness of any connection types is between ideal rigid joint and hinged joint.
The shoulderbeam is a joint point between the upper and lower part of polystyle columns.Based on its mechanical analysis,the shoulderbeam is simplified to an elastic hinge with angle stiffness.
The team also noted a hinged flap near the base of the wing, called an Alula, which is deployed at right angles to the wing, which may be being used as a air flow-control device.