Bearing Fixity [EX1-CUG]

Navigate to Superstructure > Boundary Conditios > Bearing Fixity

Select the first cell in the "Insertion Point" column, and then click on the "Pick" button in the resulting window.

Choose the insertion points that will define the boundary conditions for the superstructure. For each location, specify the fixities or stiffness values based on the bearing types in the Tx, Ty, and Tz directions.

Select the insertion points for each bearing.

Set Tx/Ty/Tz/Rx/Ry/Rz as in the figure.

To determine the values for Tx, Ty, and Tz firmness, derive them from the firmness characteristics of your mattress pad.
In this Bridge, Ty and Tz remain constant.

For Tx, only the IP1 and IP2 bearings have assigned values. This selection is due to the anticipation that axial forces will be accommodated by these two supports during the construction of the girder stage.

Setting a value for the Rx parameter serves to uphold torsional stability. Introducing a non-zero Rx value becomes necessary to address stability concerns when constructing a beam without any transverse components like diaphragms or decks. In this scenario, all supports are assigned a value of 10.

Set Transfer Force to Substructure as Yes for all bearing locations.
If you select "Yes," it will create a two-node spring between the pier cap and girder. If you select "No," it will create a one-node spring at the bottom of the girder.

If you do not model the substructure, such as abutment locations, it is necessary to select "Transfer Substructure" as "No." On the other hand, selecting "Yes" is important when substructures are modeled at bearing locations.

Navigate to Bearing Fixity under Boundary Conditions on the tree view.

Copy Articulation from model inputs and paste into OpenBrIM.