1. BIM in Structural Design October-2014Dr. Walid Al-Awad 1 Building Information Modelling

2. BIM in Structural Design Using BIM tools, the following vocabularies are introduced Beams Girders Truss Columns Walls Planer elements, floors October-2014Dr. Walid Al-Awad 2

3. BIM in Structural Design Braces Arches Cables Foundation October-2014Dr. Walid Al-Awad 3 Structural Modelling, basic definitions

4. FEM modeling elements October-2014Dr. Walid Al-Awad 4 FEM modelling elements

5. BIM structural analysis The figure below illustrates details about the various BIM structural analysis tools October-2014Dr. Walid Al-Awad 5 PRELIMINARY ANALYSIS

6. Structural Analysis In building structures, applied loads flow along the members and joints to the external supports (i.e., foundations). Because the applied loads cause internal forces in the members and joints, one can visualize the supporting structural elements as substituted by equivalent, multifaceted three-dimensional (3D) force systems. Each element of the structure (beams, columns, trusses, slabs, surface objects, etc.) in turn has its own local coordinate system October-2014Dr. Walid Al-Awad 6

7. ANALYTICAL MODELS October-2014Dr. Walid Al-Awad 7 The analytical model of the structure is an abstract mathematical construct of an idealized structure that simulates the real building structure. Analytical models utilize simplified assumptions, such as for connecting members (hinged or rigid). It is important to emphasize that only analytical models of the structure can be analyzed and not the real structure

8. ANALYTICAL MODELS The analytical model treats the structure as an assembly system of its physical objects. It breaks down the building structure into its supporting elements, connections, material, and external loads. The development of the analytical models is the most important step in the structural analysis phase. The computer analysis of the developed analytical model of the structure is based on the finite element method (FEM) as a mathematical tool by which numerical methods approximate the equations describing the behavior of the structure. October-2014Dr. Walid Al-Awad 8

9. ANALYTICAL MODELS October-2014Dr. Walid Al-Awad 9 Relationship between physical and analytical structural models. Relationship between (a) physical and (b) analytical models

10. ANALYTICAL MODELS In the Revit platform, the analytical model of the structure is a simplified three dimensional (3D) representation of the full physical description of a structural model; all structural elements are connected to each other continuously. It is known also as the “stick model.” The analytical model consists of those structural elements, geometry, material properties, nodal restraints, external supports, and loads that together form an analytical model for structural design. Revit creates the analytical model automatically while the user creates the physical model that can be exported to analysis and design applications. October-2014Dr. Walid Al-Awad 10

11. ANALYTICAL MODELS MODELING RULES: In the physical model, every structural object (beam, column, truss, etc.) must be supported with a point support. A structural floor must have one of the following supports: at least three point supports, one line support and a point support not located on the line, two line supports that are not collinear, or one surface support. A structural wall must have at least two point supports or one line support. October-2014Dr. Walid Al-Awad 11

12. structural support October-2014Dr. Walid Al-Awad 12 ConcentratedTriangular Perimeter Perimeter with transitional

13. structural support October-2014Dr. Walid Al-Awad 13

14. ANALYTICAL MODELS The modeling rule for a structural brace element requires only two point supports. These supports can be one of the following: structural columns, continuous or isolated foundations, beams, floors, walls, or ramps. FOUNDATIONS Foundation elements are an important part of the structural modeling as they represent the interface between the upper structure and the geological subsurface. Isolated foundations (footings) are stand-alone families that are part of the structural foundation category. October-2014Dr. Walid Al-Awad 14

15. PRELIMINARY ANALYSIS FEM and Revit Extensions The FEM from the structural engineer typically runs on its own platforms and does not interface with any BIM software. Autodesk Extensions changed this process by introducing FEM tools that are fully linked to Revit based on Autodesk Robot™ Structural Analysis Professional (Robot). Autodesk Extensions for Autodesk Revit software provide a full range of tools for preliminary structural analysis (see next Slid). These tools are based on the FEM software package Robot. October-2014Dr. Walid Al-Awad 15

16. PRELIMINARY ANALYSIS October-2014Dr. Walid Al-Awad 16 They are fully Integrated with Revit. These extensions provide a vehicle to perform preliminary structural analysis computations in Revit, as well as produce professional reports for documenting the work.

17. PRELIMINARY ANALYSIS Revit provides a direct link to Robot and provides bidirectional flow of data between the two programs. Robot is feature-rich FEM structural analysis and design software capable of modeling and analyzing many types of building structures. Robot enables Revit users to directly analyze their models without oversimplifying or interfering with the 3D building model to satisfy the restrictions of their chosen analysis solution. October-2014Dr. Walid Al-Awad 17

18. PRELIMINARY ANALYSIS These extensions provide an instrument to perform less- complicated structural calculations in Revit, as well as produce professional reports for documenting the work. The following sections illustrate the application of these extension tools in performing preliminary structural analysis and design. Load Takedown The Load Takedown tool allows you to perform a simulation of the flow of forces in different structural elements in a BIM model caused by gravity loads. October-2014Dr. Walid Al-Awad 18

19. PRELIMINARY ANALYSIS one needs to launch the Load Takedown tool from the Extensions tab under Analyze (Figure ). This will open the interface shown in Figure. Users can make further changes to the model if desired by modifying geometry, material parameters, support conditions, loads, and load cases. Load Takedown tool. October-2014Dr. Walid Al-Awad 19

20. PRELIMINARY ANALYSIS The user interface for the tool is generally divided into three main parts as illustrated in Figure. Part 1 of the dialog displays options for selecting items used to define geometry, supports, load cases and combinations, loads, and parameters; perform analysis computations; and receive parameter results and reports. Part 2 in the center is a graphical viewer of the BIM model under consideration. In part 3 at the bottom, there are tabs that display a table of results depending on the tab selection. October-2014Dr. Walid Al-Awad 20

21. PRELIMINARY ANALYSIS October-2014Dr. Walid Al-Awad 21 Exported BIM model in Robot showing meshes for the planar element

22. PRELIMINARY ANALYSIS October-2014Dr. Walid Al-Awad 22 Load path using Load Takedown tool: (a) BIM model; (b) analytical model showing gravity. Beam Analysis After understanding the load path in the structure, the beam analysis tool can be used to perform static analysis of beams to determine the internal forces and diagrams

23. ANALYSIS October-2014Dr. Walid Al-Awad 23 Load path using Load Takedown tool: (c) Load Takedown results with reactions and lateral loads.

24. steel reinforcement details October-2014Dr. Walid Al-Awad 24

25. steel reinforcement details October-2014Dr. Walid Al-Awad 25 Design computation results for the selected beam: (g) beam sections; (h) steel reinforcement details.

26. steel reinforcement details October-2014Dr. Walid Al-Awad 26 Column elevation and section with steel reinforcement details

27. Truss Analysis You need to select the truss in the Revit model before invoking the Truss Analysis tool from the Extensions tab. Nodal loads must be defined before instantiating the tool from the Extensions tab. Next sild shows the truss selected in a BIM model before invoking the truss tool. After launching the tool, the dialog interface shown in Figure will appear on the screen. October-2014Dr. Walid Al-Awad 27

28. Truss Analysis October-2014Dr. Walid Al-Awad 28 Truss selected for analysis The Truss Analysis tool

29. Truss Analysis October-2014Dr. Walid Al-Awad 29 (a) normal forces caused by dead load; (b) normal forces caused by live load; (c) maximum and minimum deformation of the truss members.

30. Frame Analysis Frame Analysis :With the Frame Analysis tool, one can analyze any 2D subframe of the BIM model. The tool performs static analysis of 2D frames. It is important to recognize that the extension analyzes this subframe as a 2D frame. For loads applied to the frame, this Extensions tool computes elements acting in the plane of the frame and applies these values to the frame (elements that are perpendicular to the plane of the frame are ignored). The tool replaces with supports all elements adjoining the frame (e.g., edge girders) that lie in a plane different from the plane of the frame. October-2014Dr. Walid Al-Awad 30

31. Frame Analysis Before instantiating the Frame Analysis tool, one should select elements of the frame (see Figure). Using the options on the Calculations tab one can select a load Case and a quantity for which results are to be presented in the graphic viewer and in the results table (Reactions, Displacements, Internal forces). October-2014Dr. Walid Al-Awad 31

32. Frame Analysis With the Frame Analysis tool, one can analyze any 2D subframe of the BIM model. The tool performs static analysis of 2D frames. It is important to recognize that the extension analyzes this subframe as a 2D frame. For loads applied to the frame, this Extensions tool computes elements acting in the plane of the frame and applies these values to the frame. Results obtained for a defined frame model are displayed on the Calculations tab in graphical. In addition, data can be presented in an HTML report, saved to a file, or sent to a Microsoft Excel or Microsoft Word document. October-2014Dr. Walid Al-Awad 32

33. Frame Analysis October-2014Dr. Walid Al-Awad 33 Static analysis of frames tool

34. Frame Analysis October-2014Dr. Walid Al-Awad 34 Setting options for the frame analysis toolCalculation settings and tabular results of the Frame Analysis tool

35. Slab Analysis The Static analysis of slabs tool can be utilized to analyze horizontal slabs defined in Revit irrespective of the type of slab. One would invoke the slab analysis tool similar to the other Extensions tools discussed. Before launching the tool, one must select a particular slab in the BIM model. Another important step in the slab analysis is to set up the meshing parameters before running the finite element computation October-2014Dr. Walid Al-Awad 35

36. Top and bottom steel reinforcement details from Robot October-2014Dr. Walid Al-Awad 36 Top and bottom steel reinforcement details from Robot: (a) top steel reinforcement for first-floor slab

37. bottom steel reinforcement for first-floor slab October-2014Dr. Walid Al-Awad 37 Top and bottom steel reinforcement details from Robot: (b) bottom steel reinforcement for first-floor slab

38. composite Section Design The Composite Design extension tool is powerful for designing composite steel beams. The tool can analyze and design steel beams supporting concrete slab or slabs that are concrete on a metal deck. October-2014Dr. Walid Al-Awad 38 Composite steel beams

39. Building Information Modelling BIM as a promise to offer a high quality project as well as time and cost savings. The ability to visualize the facility as a 3D model helps owners to gain a better understanding, early in the design process of the look of their final project. Software for BIM.. Revit, Tekla, ArchiCad……. October-2014Dr. Walid Al-Awad 39

40. Building Information Modelling The End October-2014Dr. Walid Al-Awad 40