EK447
In the membrane theory, a thin shell is statically determinate.
EK148
If the beam was originally statically determinate, plastic hinge reduces it to a mechanism, and prevents it from supporting any additional load.
EK146
If there are a sufficient number of pin-joints to make the structure statically determinate, then each member will act independently of the others, and may be designed as an isolated […]
EK67
The pin-joined frame is recognized as statically determinate by the three members in a triangle, resulting in the three unknown axial forces which can be solved by the three equations […]