Frame Analysis overview

Use Frame Analysis to understand the structural integrity of a given frame with respect to deformations and stresses, when subjected to various loading and constraints. Once you define the criteria, you can run the simulation and view the behavior relative to the conditions you defined. Simulations help you identify performance issues and find better design alternatives.

Beam elements are linear. Frame analysis does not support curved beams. So the curved beams must be split into small linear pieces.

Each beam element has six degrees of freedom at the beam start and beam end (three rotational and three degrees of freedom of displacement). Nodes on beams define somehow important points on the structure. They can be used to define forces, for example. In modal analysis, nodes can concentrate masses.

The following key functionality is available in Frame Analysis:

  • Structural static and modal analysis of one or more simulation studies.
  • Automatic adaptive features for controlling accuracy of results.
  • Large selection of boundary conditions (loads and constraints).
  • Extensive post-processing functionality for 3D viewing of the results, and publishing Web reports.

Frame Analysis environment

The Frame Analysis interface is divided into two main areas: the Frame Analysis browser, and the graphics region. These areas display content associated with the active simulation. Inactive simulations have a gray background.

Frame Analysis browser

Displays the simulations with assembly and simulation parameters in a hierarchical view with nested levels of feature and attribute information. You can:

  • Copy whole simulations.
  • Right-click a node for context menu options.
  • Expand the folders, select the nodes, and see the selection cross-highlight in the graphics region.

Graphics Region

Displays the model geometry and simulation results.

  • Updates to show status of the simulation.
  • Includes view manipulation tools.

Access the Frame Analysis

You can access the Frame Analysis commands using two panels on ribbon:

 
  • Click Environments tabBegin panelFrame Analysis
  • Click Design tabFrame panelFrame Analysis

Frame Analysis workflow

From a high-level perspective, a typical frame analysis workflow looks like the following:

  1. Set expectations: Estimate physical behavior using a conceptual model.
  2. Pre-processing: Enter physics into the model and define analyses to perform.
  3. Solving: Solve the mathematical model.
  4. Post-processing: Display and evaluate the results.
  5. Review expectations: Compare the results with the initial expectations.
  6. Conclusion (Improve Inputs): Do the results match the expectations?
  7. If the answer is NO, you review and modify the inputs to improve the results. The modifications could include, but are not limited to: suppressing unwanted beams, changing the loads or constraints, changing the analysis type, and so on. There are many avenues you can explore to refine the analysis results to bring them in line with expectations. The point is, the refinement is a highly iterative process.
  8. If the answer is YES, your analysis work is concluded. A likely result is that your design is refined and improved.

Inventor Frame Analysis workflow

When you start Frame Analysis, the Frame Generator assembly model is automatically converted to beams and nodes. The information that is read from the source model include:

  • Beam section data
  • Beam materials
  • References of boundary condition are validated
  • Start and end points of beams are joined within specified degree of tolerance
  • Report displays the insufficient materials, or improper cross-sections properties

The following is an example of a typical workflow for analyzing a frame structure using Inventor Frame Analysis. The steps are not exhaustive, and they do not represent the only steps you can use in your analysis.

In this numbered list, the following applies:

  • Steps 1 through 9 are pre-processing.
  • Step 10 is the solving step.
  • Step 11 is the post-processing step.
  • Steps 12 through 15 are steps for improving inputs.
  1. Open an assembly which contains frame components created using Frame Generator tools.
  2. Enter the Frame Analysis environment.
  3. Click Create Simulation.
  4. Specify the simulation properties. The beam model is automatically converted into idealized nodes and beams to conduct structural analysis. The graphics window displays beams, nodes, and the gravity glyph. The Status folder in the browser displays the insufficient beam materials and cross-sections.
  5. Exclude beams and boundary conditions you do not want in the simulation.
  6. Specify material and physical properties for beams participating in the analysis.
  7. Specify and apply the constraints.
  8. Specify location and magnitude for loads.
  9. Evaluate the connections and specify, as needed.
  10. Run the simulation.
  11. View the Results.
  12. Make necessary changes to refine the assembly. Changes can include adding nodes, loads, and constraints or suppressing problematic ones.
  13. Rerun the simulation to update the results.
  14. Repeat the process until you optimize the component.
  15. When ready, create reports based on the results.

Frame Analysis settings

The Frame Analysis settings are applicable on a per document basis. These settings define the defaults for all simulations. If you change the settings while working in a simulation, the simulation is affected immediately.

Specify values in Frame Analysis

When you define loads and constraints in Frame Analysis, you can use Heads Up Display (HUD) and grips to define the inputs. Or, you can set values in the appropriate dialog boxes.

When you select Use HUD in Application option in the General tab of the Frame Analysis Settings dialog box, Heads Up Display is used as default method during edit. You can still display dialog boxes, however. Select the appropriate command in the ribbon, right-click in the graphics window and select More Options.

Warning messages

Warning messages are listed in the Status folder in the Frame Analysis browser. When you create a simulation and assembly frame model is automatically converted to beams and nodes, the messages about insufficient beam materials and cross-sections display. When you run a simulation, all messages about simulation display. Sometimes the data are critical and simulation fails when you run the Simulation. Then, the separate dialog box displays as well. Warning messages display with icon. Error messages display with icon.

Error message indicates that the simulation cannot proceed without modification. For example, the simulation can fail if you have an insufficient material assigned to a beam.

This error message prevents the simulation from continuing without modification. In this case, change beam material. Click the Material command on the Beams panel and select the material in the Beam Material dialog box. Or, change the material in the source model directly, and click the Update command in the Beams panel to recompute the beam model.

Right-click and select How To… to open a Help page with a list of warnings and errors that can occur when you run simulations, and suggestions on resolving them.

Procedures

How to analyze frames using Frame Analysis

  1. Use the Frame Analysis environment to perform basic analysis of frame structures. Also use it to define boundary conditions (constraints and loads) and various connections between the nodes and beams (releases, rigid links).
  2. Open an assembly that contains frame structures inserted using Content Center.
  3. On the ribbon, click Environments tabBegin panelFrame Analysis. The assembly is automatically simplified to a beam calculation model. The graphics window displays beams, nodes, and the gravity glyph. The Status folder displays the insufficient beam materials and cross-sections.
  4. Click Frame Analysis tabManage panelCreate Simulation. In the Create New Simulation, set the simulation properties, and click OK. An assembly can keep multiple simulations with different properties.
  5. Beam Properties are based on the assembly data, but you can customize them for the simulation. On the ribbon, click Frame Analysis tabBeams panelProperties. Check the Customize box, enter the desired values and click OK. List of sections with overridden beam section properties is displayed in the Sections folder in the browser.
  6. Beam Material can be customized as well, to fine-tune the material values. To change the material, on the ribbon, click Frame Analysis tabBeams panelMaterial. Check the Customize box, use the drop-down list to select a desired material, and click OK. List of materials with overridden materials is displayed in the Materials folder in the browser.
  7. All constraints and loads use Heads Up Display and grips to define the inputs easily. More complex settings are available in the dialog boxes. (To display the particular dialog box, right-click the graphics window after you execute the command from the ribbon, and select More Options.) To avoid unnecessary usage of complex constraints and loads, typical simplified cases use appropriate simplified commands.
  8. Specify constraints. Select beam or node to specify their origin. Use glyphs or dialog boxes to specify the origin and values such as Magnitude or Angle in Plane.
  9. A similar interactive approach is used to define the loads. The HUD always corresponds to the currently selected grip. Enter an exact value of the given parameter directly. Define Offset using absolute or relative values.
  10. When the loads and constrains are defined, click Simulate to generate accurate results. By default, the simulation scene displays the displacement values.
  11. The Results incorporate different kinds of output properties. Selection of a browser node displays the appropriate results.
  12. To display important results for given beams, you can add user-defined diagrams to the graphics window. On the ribbon, click Frame Analysis tab Result panel Diagram. You can adjust the display of beam diagrams in the Diagram Scales dialog box. In the browser, select Diagrams, right-click, and select Diagram Scales .
  13. You can easily animate the results. On the ribbon, click Frame Analysis tabResult panel Animate.
  14. You can customize the Color Bar to fulfill your needs. On the ribbon, click Frame Analysis tab Display panel Color Bar.
  15. Report includes all the simulation data and outputs. To create a report, click Report on the Publish tab.

You can also edit the simulation properties. You can change Static analysis to a Modal Analysis. Modal analysis provides modal frequency results. To change the simulation properties, select the Simulation node in the browser, right-click, and select Edit Simulation.

Individual simulations can use different positional representations of the assembly. The beam placements differ.

Frame Analysis browser

The Frame Analysis browser shows the mechanism’s elements. It provides access to each of them so that you can select, modify, or remove them.

In an assembly, the Frame Analysis browser displays the document name with unique simulation nodes beneath it. The component, can have multiple simulations. Each simulation node contains the subfolders for Nodes, Beams, Materials, Sections, Rigid Links, Releases, Constraints, Loads, Results, and Status.

The component node displays the assembly components based on the View Representation you specify. You can select features in the browser and apply loads and constraints to the selection. When you select a feature in the browser, the feature highlights in the model.

Each simulation can have a different set of materials, loads, constraints, and corresponding sets of results. Expand a Results node to select results you want to display. In the graphics window, you can view the outcome of the simulations and compare iterations. The browser background for inactive simulations is gray to differentiate between the active and inactive state.

Each node has a context menu with commands available for that context.

Element names

The Frame Analysis browser contains the following folders:

Assembly

Name of the mechanism.

Simulation

Simulation name (assigned during simulation creation), a colon (:), and the occurrence number.

Nodes

"Node", a colon (:), and the node number (assigned according to the order of node creation).

Beams

"Beam", a colon (:), and the beam number (assigned according to the order of beam creation).

Materials

Contains set of beams with overridden materials.

Sections

List section types included in the structure.

Rigid Links

"Rigid Link", a colon (:), and the rigid link number (assigned according to the order of rigid link creation).

Releases

"Release", a colon (:), and the release number (assigned according to the order of release creation).

Constraints

"Fixed Constraint", "Pinned Constraint", "Floating Pinned Constraint", "Custom Constraint", a colon (:), and the constraint number (assigned according to the order of constraints creation).

Loads

Gravity, and "Force", "Continuous Load", "Moment", "Bending Moment", "Axial Moment", a colon (:), and the load number (assigned according to the order of loads creation).

Results

Contains all results graphs, including user-created Diagrams.

Status

Contains status messages with warnings or errors.

Browser hierarchy

Level OneLevel TwoLevel ThreeLevel FourLevel Five
Assembly Simulation    
    Nodes  
      Node
    Beams  
      Beam
    Materials  
      Material override
    Sections  
      Section override
    Rigid Links  
      Rigid Link
    Releases  
      Release
    Constraints  
      Fixed  
      Pinned  
      Floating  
      Custom  
    Loads    
      Force  
      Continuous Load  
      Moment  
      Axial Moment  
      Bending Moment  
      Gravity  
    Results (Static Simulation)  
      Displacement
      Loads  
        Fx
        Fy
        fz
      Moments
        Mx
        My
        Mz
      Normal Stresses  
        Smax
        Smin
        Smax(Mx)
        Smax(My)
        Smin(mx)
        Smin(My)
        Saxial
      Shear Stresses
        Tx
        Ty
      Torsional Stresses
        T
      Diagrams
    Results (Modal Simulation)  
      Modal Frequency
        F1 0.54 Hz
        F2 0.95 Hz
        F3 2.27 Hz
        F4 4.15 Hz
        F5 6.70 Hz
        F6 7.27 Hz
        F7 10.5 Hz
        F8 26.73 Hz
        ...
    Status  
      Solver

Browser node context menu commands

Besides the normal context menu entries, such as visibility, the following context menu commands are unique to the Frame Analysis environment:

Browser nodeCommandDescription
AssemblyCreate SimulationDisplays the Create New Simulation dialog box where you can modify the selected properties of the new simulation.
  Frame Analysis SettingsDisplays the Frame Analysis Settings dialog box where you can modify the selected properties of the new simulation.
SimulationActivateMakes the selected simulation the active simulation. Deactivates the current simulation if there is one.
  EditDisplays the Edit Simulation Properties dialog box where you can modify the selected properties of the simulation.
  SimulateRuns the simulation to obtain results for actual inputs.
  Copy SimulationCopies the selected simulation and pastes it into the current document browser, making it the active simulation.
  DeleteDeletes the selected simulation.
NodesCustom NodeEnables you to add a node to a beam you select.
BeamsBeam MaterialsDisplays the Beam Material dialog box where you make alternate material assignments for analysis purposes.
  Beam PropertiesDisplays the Beam Properties dialog box where you make alternate material assignments for analysis purposes.
MaterialsBeam MaterialsDisplays the Beam Material dialog box where you make alternate material assignments for analysis purposes.
SectionsBeam PropertiesDisplays the Beam Properties dialog box where you make alternate material assignments for analysis purposes.
Rigid LinksRigid LinkDisplays the Rigid Link dialog box to define a rigid link.
ReleasesReleaseDisplays the Release dialog box to define a release.
ConstraintsEditDisplays the Edit (Type) Constraint dialog box according to the selected type. Constraints can be modified at any time in the process.
  ReactionsDisplays the Reactions dialog box reporting reaction forces and reaction moments.
  DeleteDeletes the selected constraint.
  SuppressRemoves the selected constraint from the components being analyzed.
LoadsEdit (load type) Displays the Edit (load Type) dialog box according to the selected type. You can define or modify load parameters.
  SuppressRemoves the selected load from the components being analyzed.
  DeleteDeletes the selected load.
ResultsActivateMakes the selected simulation result the current and displays it in the graphics region. The command is disabled when not applicable.
  SimulateRuns the simulation to obtain results for actual inputs.

Browser node decorations

 

When you change components within the assembly, and switch to the Frame Analysis environment, the lightning bolt status icon displays to the left of the browser node of Beams and Nodes that are not up-to-date with the original model.. It alerts you to update the simulation or results.

Beams and Nodes

You can view the nodes and beams included in the structure under the Beams and Nodes folders.

  • By default, the nodes and beams are named as Node:1, Node:2, and so on. You can rename them if appropriate.
  • Click the node to select, and then click again to rename the node.
  • You cannot edit, delete, or exclude from simulation nodes that were converted from original assembly. Custom nodes can be deleted, edited, or excluded from simulation.
  • Beams that were converted from original assembly can be excluded from simulation.

Loads and Constraints

You can view the applied loads and constraints under the Loads and Constraints folders.

  • By default, the loads and constraints are named as Force:1, Force:2, and so on. You can rename the forces if appropriate.
  • Click the node to select, and then click again to rename the node.
  • Right-click the node, and then click Edit to open the selected load or constraint.
  • Right-click any constraint node to view Reaction Forces and Reaction Moment.

Releases and Rigid Links

You can view the list of releases and rigid links under the Releases and Rigid Links folders.

  • By default, the Releases and Rigid Links are named as Release:1, Release:2, and so on. You can rename the forces if appropriate.
  • Click the node to select, and then click again to rename the node.
  • Right-click the node, and then click Edit to open the selected release or rigid link.
  • You can also delete or exclude releases and rigid links from simulation.

Results

This folder displays the various analyses the structure has undergone considering the defined conditions.

Click the desired result to be displayed in the graphics window.

When you perform modal analyses, the Modal Frequency folder is created.

Right-click the Diagrams folder to display diagrams for selected beams or adjust diagram scales.

Status

This folder displays the various analyses the structure has undergone considering the defined conditions.

When you create a simulation and assembly frame model is automatically converted to beams and nodes, the messages about insufficient beam materials and cross-sections display.

When you run a simulation, all messages about simulation display.

Right-click and select How To… to open a Help page with a list of warnings and errors that can occur when you run simulations and how to resolve them.

References

Frame Analysis tab

The Frame Analysis tab is made up of a series of panels, each containing one or more commands that are grouped for ease of access. Each panel has a name.

NoteThe following descriptions are not meant to be high level, to be a simple and quick reference. For more information see the Quick Reference topic for a given command.

The Frame Analysis tab comprises of the following panels:

Manage panel

 
Create SimulationDisplays the Create New Simulation dialog box where you define the new simulation.

Beams panel

 
UpdateUpdates the beam model from source assembly within specified state.
 
PropertiesDisplays the Beam Properties dialog box where you can change the original beam geometry data.
 
MaterialDisplays the Beam Material dialog box where you define the materials to override the original material definition.

Constraints panel

 
FixedDisplays the Fixed Constraint dialog box from which you select geometry and further define the constraint.
 
PinnedDisplays the Pinned Constraint dialog box from which you select geometry and define the constraint.
 
FloatingDisplays the Floating Pinned Constraint dialog box from which you select geometry and further define the constraint.
 
CustomDisplays the Custom Constraint dialog box from which you select geometry and further define the constraint. You can set the displacement and the rotation of constraint.

Loads panel

 
Force Displays the Force dialog box from which you specify a force.
 
Continuous LoadDisplays the Continuous Load dialog box from which you specify a continuous load on the 3D sketch line.
 
Moment Displays the Moment dialog box from which you specify a moment.
 
Axial MomentDisplays the Axial Moment dialog box from which you specify an axial moment.
 
Bending MomentDisplays the Bending Moment dialog box from which you specify a bending moment.

Connections panel

 
ReleaseDisplays the Release dialog box from which you define specific release conditions at beam start and beam end.
 
Rigid LinkDisplays the Rigid Link dialog box from which you define rigid links in a structure.
 
Custom NodeDisplays the Custom Node dialog box from which you add a node to a selected beam.

Solve panel

 
SimulateRuns the simulation. The progress bar is shown during simulation. After the simulation is complete, a dialog box containing brief simulation warnings and errors is displayed.

Result panel

 
AnimateAnimates the results including loads, moments, stresses, and so on. You can record a video of the animation.
 
Beam DetailDisplays diagrams for selected beam loads, moments, and stresses.
 
DiagramDisplays the Diagram dialog box from which you define diagrams to display.

Display panel

 
Color BarDisplays the Color Bar dialog box where you define the location and gradation of the color bar.
 
Beam LabelsTurns on or off the display of the beam labels.
 
Node LabelsTurns on or off the display of the node labels.
 
Smooth ShadingDisplays the color transitions using smooth shading techniques.
 
Contour ShadingDisplays the color transitions in contours, providing a hard line contrast between colors.
 
No ShadingRemoves color shading.
 
Min ValueTurns on or off the display of the minimum result.
 
Max ValueTurns on or off the display of the maximum result.
 
Boundary ConditionsControls visibility of glyphs for the different loads and constraints applied in the simulation.
 
Local SystemsTurns on or off the display of the local coordinate system of the beam.
 
Load ValuesTurns on or off the display of the values of all loads.
Pull down listAdjust Displacement ScaleSets displacement scale for visualization purposes. The setting is for the graphical display and does not affect the simulation values.

Publish panel

 
ReportDisplays the Report dialog box where you define the report content and then publish the report.
 
ExportExports Frame Analysis data to RTD format.

Settings panel

 
Frame Analysis SettingsDisplays the Frame Analysis Settings dialog box where you specify the default parameters for all new simulations. You can override these settings on a per simulation basis.

 

Frame Analysis Settings - General tab

Frame analysis settings are applicable to all frame simulations. Whenever a new frame simulation is started, these preferences are used. You can override the global settings on a simulation basis by changing the simulation properties.

This section discusses the controls on the General tab.

Access:

Ribbon:Frame Analysis tabSettings panel Frame Analysis Settings
Heads Up Display (HUD)  
  Use HUD in ApplicationSelect to use Heads Up Display in Frame Analysis environment. Heads Up Display is set as the default method during edit.
Colors  
  Click the arrows at the end of the edit field to open the Color dialog box. You can specify the display colors for loads, constraints, gravity, nodes, custom nodes, beams, and rigid links.
Scales  
  Specifies the size of nodes, loads, and constraints as a percentage of the model bounding box.
Initial Label Placement Distance  
  Specifies the initial displacement distance of the labels relative to where you click in the model. The setting is a percentage of the diagonal of the model bounding box. Changes to the setting do not affect the positions of existing labels.

Frame Analysis Settings - Beam Model tab

Frame analysis settings are applicable to all frame simulations. Whenever a new frame simulation is started, these preferences are used. You can override the global settings on a simulation basis by changing the simulation properties.

This section discusses the controls on the Beam Model tab.

Access:

Ribbon: Frame Analysis tabSettings panel Frame Analysis Settings
Beam model  
  Create Rigid Links

Enables to create rigid links manually. Clear the box not to automatically create rigid links during model conversion. You can create them manually based on your needs and preferences.

  Tolerance

Specify the maximum distance between beams to consider in automatic conversion.

When the distance between two beams is smaller than sizes of sections multiplied by tolerance, then rigid link connection is created between nearest nodes.

The range of valid inputs is from -100% to 500%. If you set the value to 0, the beams must be positioned right next to each other. Due to an inaccuracy, it is possible that even beams next to each other are not connected. Therefore the default value is set to 2. Positive values create rigid links between beams that have gaps between them, gap weld for example. Negative values define that there must be an intersection between beams to create rigid links.

To learn more about rules applied during automatic conversion of frame assembly, see the Automatic Model Conversion Help topic.

  Trim Mitered Beam Ends

When selected, the overlaps are trimmed during automatic model conversion.

Original models  
  Display as:

Specifies the default visibility settings for all components (beams and other parts) after the conversion.

  • Invisible - the component visibility is turned off.
  • Transparent - uses the disabled component visibility characteristics
  • Shaded - uses the standard shaded component settings.

Frame Analysis Settings - Solver tab

Frame Analysis solver settings are applicable to all simulations. Whenever a new simulation is started these preferences are used. You can override the global settings on a per simulation basis by changing the simulation properties.

This section discusses the controls on the Solver tab.

Access:

Ribbon: Frame Analysis tabSettings panel Frame Analysis Settings
Solver Defaults  
  DSC Algorithm (Beam Releases)

Select to enable the discontinuity element during calculations of a structure where releases are defined.

Results  
  Beam PointsSpecify number of beam points that are calculated by solver.

DSC Algorithm

DSC Algorithm enables you to calculate a structure with releases.

For any beam, for which you defined any type of analysis, with the following releases:

  • Regular
  • Unilateral
  • Elastic
  • Elastic and unilateral

The following operations are performed:

  • A new node is generated in the structure when the structure model is generated.
  • The input element with the release is modified. The new node replaces the old one in the element (the old node remains in the other structure elements).
  • Between the old and the new node, Robot creates the DSC element (Discontinuity). See the following image:

The DSC element is a 2-node element, where the nodal forces are generated according to the following formula:

Using the DSC elements lets you define elastic releases in a beam.

Frame Analysis Settings - Diagrams tab

Sets options for displayed beam diagrams.

Access:

Ribbon: Frame Analysis tabSettings panel Frame Analysis Settings
Positive and Negative Values  
  Undifferentiated

Specifies the style of display of positive and negative values.

Select not to differentiate between positive and negative values in the graph results.

  Differentiated

Specifies the style of display of positive and negative values.

Select to differentiate between positive and negative values in the graph results.

Filling  
  Fence

Specifies the style of filling in the graphs results.

Select to use fence style displaying the graph results.

  Filled

Specifies the style of filling in the graphs results.

Select to use filled style displaying the graph results.

Colors  
  Click the Colors button to open Graphs Colors dialog box where you can select colors for loads and stresses displayed in the graphs diagram.

Diagrams Colors

Select colors for loads and stresses displayed in the Diagram dialog box.

Access:

Ribbon: Frame Analysis tabSettings panel Frame Analysis Setting. Switch to the Diagrams tab, and click Colors.

Click the buttons next to the stresses and loads edit fields to specify color to be displayed in the graph diagrams.