You finish the concrete frame in Revit, open Robot and wait for the model to arrive. It does not, because an analysis program does not want concrete solids. It wants a diagram of members, nodes, supports and loads.
The analytical model in Revit is that diagram. It lives in the project file, next to the physical model. This article walks through 13 steps in Revit 2027: generate the analytical model for the whole building in one go, inspect members and nodes, add supports and loads, and stop where the model hands over to Robot Structural Analysis. For the full workflow from modelling to drawings, the Institute runs a Revit Structure course.
How the analytical model differs from the physical model
The physical model is what you see on drawings: columns with sections, beams with depth, slabs with thickness. The analytical model has no thickness at all. Columns and beams become analytical members running along their axes, floors and walls become analytical panels, and the points where members meet are analytical nodes.
The two models stay associated. According to the Revit 2027 help, a member inherits material, structural role, cross-section and cross-section rotation from its physical element; a panel inherits material, structural role and structural layer thickness.
Not every element gets an analytical twin. The automation handles vertical and slanted columns, straight and arc beams, floors, foundation slabs and straight walls. Piles placed as isolated foundation families are not on the list, so the generated diagram stops at the column bases.
Before you build the analytical model in Revit
You need Revit 2027 and a structural project with columns, beams and floors on grids and levels. This article uses the Institute's four-storey building on piles. Work on a copy, because the analytical model adds hundreds of elements to the file.
A dedicated 3D view helps. The boundary-condition part needs a project that contains boundary condition families; projects started from Revit's Structural Analysis-DefaultMetric.rte template have them.
Getting columns and beams onto the right grids is covered in structural columns and beams in Revit. This article belongs to the Institute's Revit Structure series.
Revit analytical automation, step by step
Step 1 — Remove the view template from the 3D view
Open the default 3D view with the small house icon on the Quick Access Toolbar. In Properties, scroll to Identity Data and click the button in the View Template row.
The Assign View Template dialog shows that the @P21-3D KẾT CẤU template has Include ticked for V/G Overrides Analytical. While the template keeps that row, you cannot turn the analytical model on in the view. Pick None and click OK.
Step 2 — Turn on the analytical categories
Click Edit... in the Visibility/Graphics row of Properties, or type VG. Switch to the Analytical Model Categories tab.
Tick Show analytical model categories in this view. Analytical Nodes is off by default; tick it, because the checks in step 8 rely on nodes. Click OK.
Step 3 — Open the Analyze tab
Click Analyze on the ribbon. Every analytical tool sits on the Structural Analytical Model panel.
Member and Panel draw members and panels by hand. Link joins two nodes. Boundary Conditions and Loads add supports and loads. The small arrow next to the panel name opens four more commands: Load Cases and Combinations, Load Cases Display, Boundary Conditions Settings and Loads Scaling Display.
Step 4 — Run Physical to Analytical For Buildings
Click Analytical Automation. The menu has three entries.
Choose Run Physical to Analytical For Buildings. The second entry works the other way round, building physical elements from an analytical diagram; Automation Customization is for those who want to adjust the automation rules.
Step 5 — Review the selection and click Run
Revit preselects every structural element it can process and highlights it in blue. The ribbon switches to the Modify | Modify contextual tab.
To leave out elements such as parapets or partitions, click Edit on the Selection panel and adjust. The sample model stays as it is, so click Run. A warning appears in the corner: Some levels are hidden. The alignment plans will also consider the hidden levels. Revit is telling you that it aligns members to hidden levels too. When the ribbon returns to normal, the run is finished.
Checking members and Revit analytical nodes
Step 6 — Look at the analytical model alone
Open Visibility/Graphics again, go to Model Categories, clear Show model categories in this view and click OK. The concrete disappears and only the analysis diagram remains.
Members are orange and nodes are black dots. The view control bar has a quick toggle whose tooltip reads Hide Analytical Model while the model is shown. Scan the whole diagram: a member floating away from a node or a storey with missing beams is the first place to look.
Step 7 — Read an analytical member
Click a beam member. The ribbon switches to Modify | Analytical Members and Properties shows the member.
Structural Material already carries the concrete of the physical beam, Structural Role is Beam and Section Type is a rectangular concrete section. Further down are Analyze As and the Releases / Member Forces group, where Start Release is Fixed. Highlight Association helps you find the physical element behind the selected member.
Step 8 — Check the nodes
Click a black dot. The Modify | Analytical Nodes tab appears.
Three rows matter most. Associated Level tells you which level the node belongs to, Associated Level Offset of 0 means it sits exactly on that level, and Connection Status reads Connected when the node joins other members. Can Be Hosted decides whether the node may attach to another member or panel. A node off its level usually means the physical element sits off its grid or level; fix the physical model, then check the node again.
Boundary conditions in Revit and loads in Revit
Step 9 — Check that the project has boundary condition families
Click Boundary Conditions on the Analyze tab. In the sample model Revit does not start the command; it shows a message.
No Boundary Conditions Families Loaded means the project lacks the support symbol families. Click Close. Projects started from Structural Analysis-DefaultMetric.rte already have them; for older projects, load those families first. The Boundary Conditions Settings tab under Manage › Structural Settings shows the same message when the families are missing.
Step 10 — Place supports at the column bases
In a project with the families, click Boundary Conditions. The Modify | Point Boundary Conditions - On Host tab appears.
Use Point for columns, Line for walls and Area for mats. In Properties, State defaults to Fixed: X/Y/Z Translation and X/Y/Z Rotation are all locked. Change State for a pinned support. The status bar asks you to pick an analytical member or panel corner; click the bottom end of each column member.
Step 11 — Define load cases
Click the arrow next to the Structural Analytical Model panel name and choose Load Cases and Combinations.
The sample model already lists DL1 as Dead, LL1 as Live, wind, snow and seismic cases, plus user cases such as Tinh Tai, Hoat Tai and GIO X. Click Add for a new case. Automate under Load Combinations only becomes active once both Region/Country and Design Code are chosen; the region list includes Eurocode and twenty countries, but not Vietnam. Combinations to Vietnamese standards are therefore usually built in the analysis program.
Step 12 — Place a line load on a beam
Click Loads, then Line Load on the Loads panel. The Modify | Line Load - On Host tab appears.
In Properties pick the Load Case, keep Uniform Load ticked and type a value in Fz 1; a negative value points down. Click the beam member. The purple arrows along the roof beam in the first image are the finished load. Area Load works the same way on analytical panels.
Handing over to Robot Structural Analysis
Step 13 — Find the send command on the Structural Analysis panel
Look at the right end of the Analyze tab. With Revit alone installed, the Structural Analysis panel only holds Results Explorer, and it is greyed out.
The command that sends the model to Robot Structural Analysis is not part of the Revit installer. According to the Revit 2027 help, the integration extension is downloaded through Autodesk Access; once installed, it sits under Analyze › Structural Analysis › Robot Structural Analysis › Robot Structural Analysis Link. The Integration with Robot Structural Analysis dialog offers Send model, Send options for the scope, and an intermediate .smxx file for another computer. Revit's own tooltip says Results Explorer displays the analysis results brought back: reactions, member and floor forces, and deformation.
Installing Robot and the link for students is covered in installing Robot Structural Analysis for students. Still choosing between Robot and ETABS? Read Robot Structural Analysis vs ETABS and ETABS, SAP2000 and SAFE compared. Autodesk's own pages: Physical to Analytical Automation and Sending a model to Robot.
When the analytical model does not work
| Symptom | Cause | Fix |
|---|---|---|
| Show analytical model categories in this view is greyed out | The view template includes V/G Overrides Analytical | Remove the template as in step 1, or edit the template |
| Nothing visible after Analytical Automation | Analytical categories are off in the view | Do step 2, or click Show Analytical Model on the view control bar |
| Elements highlighted blue, ribbon greyed, no tab with Run; Esc does not exit | Not identified; Revit stops at the preselection stage | Close Revit, reopen the file, run the command again |
| Piles have no analytical members | The automation does not process isolated foundation families | Support the column bases, or draw pile members with Member |
| Boundary Conditions shows No Boundary Conditions Families Loaded | The project has no boundary condition families | Load the families, or start from the Structural Analysis-DefaultMetric template |
| Automate for load combinations is greyed | Region/Country and Design Code not chosen | Choose both, or build combinations with Add |
| No send-to-Robot command | Robot and the integration extension are not installed | Install them as in the student installation article |
Five common misconceptions
| What people say | What Revit 2027 actually does |
|---|---|
| A finished physical model already has an analytical model | You must run Analytical Automation or draw Member and Panel |
| Revit calculates internal forces | Revit prepares the diagram; the analysis runs in Robot or another program, and Results Explorer only displays returned results |
| Loads can only be defined in Robot | Revit has Load Cases, Point Load, Line Load and Area Load on members and panels |
| The analytical model is always right | It is right when physical elements sit on their grids and levels; nodes off level need checking |
| Installing Revit gives you the Robot link | The link is a separate extension installed with Robot |
In short, the analytical model in Revit is a calculation diagram built from the model you already drew. Clean it up in Revit before sending it, and there is much less to fix on the Robot side.
Frequently asked questions
Does the analytical model make the Revit file heavier?
It adds a noticeable number of elements: every column, beam and floor gets a member or panel, plus nodes. Create it once the structure is settled, and work on a copy if you are only experimenting.
If I change a physical beam, does the analytical member follow?
Yes. According to the Revit 2027 help, the analytical model is updated from changes in the physical model, because each member stays associated with its element. Remove Association on the member's tab is for detaching a member from its physical element.
Do I need Robot to define supports and loads?
No. Boundary conditions, load cases and loads are all defined in Revit. Robot is needed for analysis and design.
Why check the analytical model storey by storey?
After each storey, open the analytical view and scan it. A member detached from its node is much quicker to fix then than after the whole building is modelled.