nThe model will be used to study the resistance to collapse when a structural element is removed, or in this case an entire module as shown in the image below. The modules are connected at the corners only to transmit the axial load down, this simplifies assembly on site by connecting only the corners and negates any load transfer through the beams, module chasis shown below. There is a gap both horizontally achieved by extending the columns below the floor and vertically by introducing a gap between adjoining modules. In the vertical gap there is a horizontal tie which will tranfer lateral forces to a core or similar and also providing a tieing resistance when the column is removed.nnI won't be releasing all the DOF, certainly in the vertical direction there will be forces being transmitted and there will be some stiffness in X and Z also. As i develop the models i may need to use springs to introduce some stiffness in these, but at the moment i am trying to replicate a previous study and progress from there. The location i am introducing the releases is where one module is in contact on the four corners with the one below, this will not be welded so it is n't fully fixed, but there will be some mechanism to fix this and may include some type of shear key, to aid alignment and resist transverse loads.nnGiven the nature of the structure i had wondered if there was a way to assemble the building similar to Solidworks, but i think the best way to proceed is using pattern in spaceclaim as you suggested and using the lists for the nodes in mechanical, as i can automatically select the columns due to their unique lenght.nnCheersnMichaeln