Deck cross section
Revit 3D using Civil Structures (Option 2) The cross section is designed by input data in Excel BRIDGE sheet described in Geometry. By running Add-Ins in Revit family file ICDAS_Profile_2D_Deck.rfa, the cross section is created automatically. This Revit family file will then customize in a Revit project file Bridge.rvt to create the 3D bridge automatically. Note that in Bridge.rvt the bridge's corridor overpass and corridor underpass must be in integration with AutoCAD Civil 3D, where the bridge location is determined. This geometry work is the first important part of the bridge project which is described in ICDAS Bridges Manual. Lusas Analysis The second part is to create a FEM model automatically. ICDAS CSB creates file LusasCSB.cmd file automatically when running Add-Ins in Revit. By importing this file in LUSAS one will get a 3D FEM model having a cross section as shown below. The cross section is designed with 5 longitudinal lines creating top left side of deck, line no. L1 to L5, and 5 longitudinal lines for top right side of deck, line no. R1 to R5. There are 9 longitudinal lines create the bottom of deck, line no. B1 to B9, see Analysis. Changing positions of these lines one will obtain a new cross section and a new bridge in both of Revit and Lusas models. Thickness and density equivalent The equivalent thickness for top and bottom plates of the deck is calculated to 175mm to present the stiffness of the plate t1, the ribs t2 and the other dimensions as show below.
Dimension of top and bottom plates (mm) Cross distance between ribs, c = 300 Upper rib dimension, c = 300 Lower rib dimension, b = 200 Height for the stiffener, h = 300 Distance to next two stiffeners, f = c/2 Upper plate thickness, t1 = 20 Rib plate thickness, t2 = 10
Figure: FEM cross section with equivalent plate thicknesses The equivalent density is calculated to 0.191x7.85tons/m3.
However, to overcome the nonlinear analysis convergence the following input has been assuming for the top and bottom plates of deck in this case study (Thickness, Density) = (175mm, 7.85tons/m3) | 
