First, the structural system has to be completely defined, including the supports. In the current example, a simple structural system is analyzed, with dead and live loads for which we will also add an accidental load.
Next, we create an accidental load case for the imposed displacements. This type of load can be generated in any load case.
We define the imposed displacement by selecting the generated load case and right clicking it. From the context menu we select "Create a load". From the window, we select "Imposed displacements".
In the properties window, we define the characteristics of the accidental load. In this example we have a 10cm displacement on the global direction Z, gravitational direction, and a rotation of 5° on global direction Y. After all the properties are introduced, click on the already defined supports at the desired imposed displacement.
The effects of the imposed displacement, defined in the descriptive model, can now be displayed after the analysis of the structural model by displaying the results - displacements, forces and stresses.