Stiffening elements can be added to both column and beams elements of moment connections. Simply select the element with left mouse button and then use your right mouse button to access a list with available stiffeners to add. Once you select a stiffener, this is added immediately, as we use default values for the dimensions.
This list with stiffening elements depends on the selected element and the type of connection. You will see a different for beams, and column, but also for moment connection and column base connections.
Mark that stiffening element add stiffness and rigidity to the connection – so there will be no stiffeners available for shear connections, nor for tubular connections, as both are assumed to hinged and to have low stiffness.