IMAGINiT Manufacturing Solutions Blog

Managing iProperties with an Inventor iLogic Form

One of the challenges we often face during the design and documentation process is getting our design team members to populate the iProperties required for Title blocks, Bill of Materials (BOM) and Vault.

Out of the box Inventor provides workflows that allow us to populate iProperties by using the iProperty editor for individual files or through the BOM editor for multiple files. However, end users often forget to populate the iProperties or miss some of the required iProperties. A couple of common excuses we hear are “the workflow is to cumbersome” or “I don’t know which iProperties to populate”.

One solution is to provide the design team with an “Easy button” that identifies the required iProperties. This can be accomplished by using Inventor’s iLogic to create a simple form that lists the required iProperties.

I know that you may be thinking “I am not a programmer”, however the workflow below outlines the basic process to create an iLogic form using simple “Drag and Drop” workflows that do not require any programming knowledge.

Creating the iLogic Form

Start by opening a new file from one of your existing drawing templates and then click on the “+” in the Inventor browser to display the iLogic Browser.

From the iLogic Browser, select the Forms Tab, right mouse click and select “Add Form”.

The Form Editor will start and will display a preview of the form.

From the Form Editor, select the “iProperties” Tab and then expand the iProperties groupings to select the desired iProperties. Drag  and drop the iProperty to the form design tree on the right. Repeat the workflow for each iProperty (Note: you can select multiple iProperties using the “Ctrl” & “Shift” keys).

Now that the basic form is created, lets make some modifications to it.

Naming the Form

In the Form Tree select “Form 1”. In the Properties Window below, edit the label name.

Add the Company Logo

If you have an image of your company’s loge, you can dress up the form by adding it to your form. This file can be one of the following formats .bmp, .gif, .png, .jpg, .jpeg, & .tiff.

From the “Toolbox” select and drag “Picture” into the Form Tree dropping it above the first iProperty in the list.
Select “Picture” from the list in the Form Tree and got to the Properties Window. Under “Appearance”, select the Browse button from the Image row and navigate the location of your logo image.

You can adjust the size of the image on the form using the settings for “Size Limits”.

Organize the iProperties

Organize your iProperties in the Form to make it easier for the users to identify the use of specific iProperties.

From the “Toolbox”, select “Group” and drag/drop it to the top of the Form Tree. In the Properties for the Group, rename the label to a meaningful value.

Select the exiting iProperties in the Form Tree and drag/drop them in to the Group(s) you just created.

Completing the Process

Now that you have created the form, save the Inventor file to your Inventor

Templates folder and distribute to the Design Team.

End User Workflow

To use the form, start a new drawing and display the iLogic Browser as described above. Click on the form button and fill in the iProperties

On-Demand: Licensing and Collaboration for Manufacturing Professionals

During our session yesterday, we covered how teams can access their Autodesk software from home, as well as ways to continue to coordinate and collaborate on designs.

 

If you have any questions about the processes and programs we discussed, please don't hesitate to reach out to your IMAGINiT representative.

Optimize Designs with Inventor Parametric Studies

When developing products, it’s important that engineers make informed design decisions. Factors like material, weight, and safety factor are typically key inputs that drive the design process. It’s an iterative process that can require hundreds of different configurations to be tested to see which performs the best and still satisfies the required criteria. Fortunately, the Inventor Stress Analysis environment has a tool called Parametric Study that quickly generates, analyzes, and sorts variations of models to help guide the designer.

Let’s use a bicycle crank arm as an example of parametric study. There are elements of the arm that might not change significantly (e.g. thread sizing, material, length). However, there are thousands of different thicknesses that could potentially work. Additionally, there are thousands of cutout shape and sizes that could be used to reduce the weight of the arm. Here are some potential arm designs with varying thickness and cutout dimensions:

Before jumping into a Parametric Study it’s best to name your key parameters in your model. For the crank arm, let’s focus on the thickness, slot depth, and slot length. Those elements will have a significant impact on the weight of the design and are easy to change.

To start a new study, click on the Environments tab in Inventor and choose “Stress Analysis.” Then click on "Create Study." In the dialogue box – use the drop-down menu to change the Design Objective to “Parametric Dimension.” Then select “OK” to begin the new stress analysis study.

Next, build a Linear Static load study in the typical fashion. This will involve assigning materials, defining loads, constraining faces, and generating assembly contacts. For the crank arm and pedal assembly, the threaded sections are assigned a bonded contact. The side faces of the pedal and crank arm are assigned a separation contact.

Both parts are assigned the material Aluminum 6061. The mesh is reduced to a global size of 3% the bounding box length. This will produce a converged and reliable result.

The square faces where the arm will attach to the crank assembly are constrained as Fixed. This means that the nodes on those faces cannot translate or rotate along any axis. A 100 lbf load is applied to the two horizontal faces of the pedal in the orientation shown below. This position of the crank arm and force value represents the maximum load scenario.

To setup the input parameters, begin by right-clicking on the model name below the analysis name in the Study browser. Then, choose “Show Parameters.”

From the dialogue box, choose the parameters that will be changing during the study. Click the check box in the “Model Parameters” column to add to the study. This will create the varying configurations for the solver. It’s best to start simple and only choose 2-4 parameters. Click “OK” to finish.

Next, click on Parametric Table from the analysis ribbon. Right-click in the Design Constraints table and select “Add Design Constraint.” The design constraints are the result values that are critical to the success of the design. These include things like Mass, Safety Factor, Von Mises Stress, Displacement, etc.

There’s list of design constraints to choose from. Highlight the constraint and select “OK” to add it to the study. For this study – Von Mises Stress (Maximum) and Mass will be used.

After you’ve selected the required design constraints, limits and criteria can be set in the table. This allows for the results to be filtered and sorted based on key values. For example – finding which configuration yields the lowest mass while still satisfying a safety factor of 2.

Parameter values can be configured in the lower table. Discreet values can be entered with commas in between. This method was applied for the thickness because the stock material will likely come in a standard size. A range of values can be entered with a dash in between. Adding a colon with an additional value specifies how many points in the range. (e.g. 2-4:5 would yield 2, 2.5, 3, 3.5, 4)

It’s recommended to create all the configurations prior to running the analysis. This will confirm that none fail and will improve the run-time of the study. Right-click in the lower table and select Generate All Configurations. Depending on how many values you’ve entered, this could take 5-10 minutes. Take a coffee break.

After generating all the configurations, it’s time to run the study. Click on Simulate from the ribbon to begin. From the drop-down menu – choose to run either an Exhaustive Set or Smart Set of configurations. Exhaustive Set will run a study on every single configuration. The Smart Set will solve the base configuration and each parameter change to the base – then interpolates the other results.

Now for the fun part! Once the study is finished, open back up the Parametric Table. For Max Von Mises Stress, I’ve entered an Upper limit of 35 ksi (the yield strength of AL6061) and a Safety Factor of 1.5. For Mass I’ve entered “Minimize” which will produce the configuration that satisfies the other criteria and minimizes mass. If the constraint is satisfied with the configuration – a green circle or checkmark will appear next to the result value.

To satisfy a safety factor of 1.5 – the study recommends a 0.5” thick crank arm with a 6” long and 0.25” deep cutout. This will produce a design that weighs 0.91 lb.

Let’s say that the design team wants to be more conservative and achieve a safety factor of 3. Simply change the constraint limit and the results will be sorted to find the correct configuration! As shown below, to achieve a safety factor of 3, the study recommends a 0.625” thick crank arm with a 5.2” long and 0.25” deep cutout. This adds some weight, but not much.

Once a satisfactory configuration has been identified it can be promoted to the model. Right-click in the lower table and select “Promote configuration to model.”

Hydrostatic Pressure loads with Inventor Nastran 2020

The most recent release of Autodesk’s advanced finite element analysis software, Inventor Nastran 2020, included some useful new features and upgrades. This includes automatic mesh convergence tools, Vault integration, corrected shell elements, and a new Hydrostatic load type.

This new load type allows the user to apply a fluid pressure that varies with the depth of fluid in a specific direction. Previous versions of Nastran In-CAD (2019 and earlier) required the user to create a variable pressure load using a table of coordinates and scalar multipliers. This approach also required the user to calculate the pressure at the bottom of the surface using the formula:

P = ρ*g*d

where the ρ (rho) is the fluid density, g is acceleration due to gravity, and d is the fluid depth. See the image below for more detail. Just like the standard Pressure load – the pressure will always act normal to the element face. NOTE: In Nonlinear Static studies, the pressure will continue to act normal to the surface even as it deforms.

Hydrostatic pressure loads can only be applied to the faces of shells and solids. With larger models and assemblies, it’s usually best to utilize shell elements to reduce the overall element count and prevent unusual stress concentrations. For the tank shown below, the walls are 1/4“ stainless steel. Due to the large size of the tank (10 ft. tall) a surface model was created so that shell elements can be easily applied. After applying a fine mesh the total element count is still only 10,000.

The process of applying a Hydrostatic Load is simple:

1. Create a new Load and use the drop-down menu to specify the type as “Hydrostatic Load.” There are no Sub Type selections for this load type.

2. Use the Fluid Density field to enter the weight density of the fluid causing the pressure. The default value will be 0.036 lbf/in^3 – the density of water.

3. Click In the “Point on Fluid Surface” box to activate the selection. Choose a work point, vertex, or use XYZ coordinates to define the top of the fluid. Only elements below this point will receive a hydrostatic pressure.

This work point can be created in the 3D model using Inventor’s work features on the 3D modeling tab. In this example – a work point was created 6 inches below the top of the tank to represent the maximum fluid volume height.

4. Define the fluid depth direction, either by selecting an entity in the model (work point or vertex), or by using the XYZ fields to define a vector. Typically it’s easiest to use the XYZ vector fields. In this example – the fluid depth direction is in the Z- direction. So the vector is entered as X=0, Y=0, Z= -1.

5. Use the arrow next to Fluid Depth Direction to change the normal direction that the pressure will be acting on the surface. The green arrows should be facing outwards in this example because the fluid is inside the tank. The arrows should also increase in size from the top to the bottom.

6. Constrain the model as required and run the analysis. In this example, the maximum displacement was 0.01” and the maximum Von Mises stress was 4198 psi.

I Now Pronounce You Revit and Vault

Adding Vault to your existing Revit environment can add a tremendous amount of value, power, and security to the current workflow.  Adding value by enhancing functionality such as, searching for specific families that are store and controlled in Vault.  Power to push and pull Vaulted files to and from BIM 360 for collaboration outside of your companies firewall.  Added security by controlling who can and cannot read, modify, and delete files once Vaulted. As well as, seeing the state the current project is in whether its currently being worked on, being reviewed by the customer or it is officially released at 100%.  Lets break down the Vault add-in below.

1. Select Go to Vault from the Vault ribbon to launch the Autodesk Vault client.
   
   
2. Log in and out of Vault from the Vault add-in.
   
   
3. Opening a file from the vault opens an existing Revit previously added to vault. When selecting the latest version of a file, Revit Server files and Central work shared files are opened from their respective locations just as they would be if opened from Revit.
   1. Opening a historical version of a file or a Read Only version of the file downloads a copy of the file from Vault and opens it for viewing.
   2. Opening a non-work shared file for editing automatically checks out the file unless the Read-Only option is selected.
      
      
4. Non-work shared files are added to a vault using the Save to Vault command. When a file is Saved to Vault, it is automatically checked into the vault.
   1. Save to Vault can only be used on Non-work shared files and Revit Family files.
   2. After Saving a file to Vault, if you continue to edit the file, the file is automatically checked back out.
      
      
5. Within Revit you can search or browse Vault for Revit family types and load, or load and place them into the current project.
   1. The Load Family feature supports files of type .rfa with or without type catalogs.
      
      
6. Link from Vault lets you link a file stored in the Vault to the current Revit Project.
   1. Link from Vault supports these file types:
      1. DGN, DWF, DWFX, DWG, DXF, IFC, RVT, SAT, SKP
         
         
7. Import from Vault lets you import CAD files or images stored in a vault into the current Revit project. If an imported file is updated it must be reimported back into Revit to see the changes.
   1. Link from Vault supports these file types:
      1. DGN, DWG, DXF, SAT, SKP, BMP, JPG, JPEG, TIF
         
         
         
         
8. Load groups from one project in the Vault into the active project with the Load Groups from Vault feature. (Make sure you are within a viewport)
   
   
   
   
   1.  Select a .rvt file and click Select to see which groups are available. Unlike in Revit, you can select which groups are loaded from Vault.
      
      
      
      
9. Use the Add Files command to add a selection of files to the vault or the Add Folder command to add multiple files contained in a Windows folder to Vault. Relationships between Revit files and associated files are created as new versions of the files are added to vault.
   
   
   
   
10. Add Sheets allows the user to print all sheets in the active Revit file and place them directly into Vault.
    
    
    
    
    
    
11. The Change Category command allows users to modify the lifecycle category for a file or group of files in Revit.
    
    
    
    
12. Changes the Lifecycle State in Vault of a currently opened model. It adds/saves model to Vault if needed.
    
    
    
    
13. Change the revision value for a file or an item in the Vault client.
    
    
    
    
14. Shared parameters are definitions of parameters that you can add to families or projects. Shared parameter definitions are stored in a .txt file independent of any family file or Revit project; this allows you to access the file from different families or projects. This file is referred to as the Shared Parameters file.
    1. Vault does not confirm the legitimacy of the shared parameters file, so if you select an invalid .txt file in the vault, it will still be activated as the Shared Parameters file.
    2. Autodesk recommends creating a shared parameters folder in the vault. Since there may be multiple types of .txt files a user can browse to inside a vault, a shared parameters folder makes it easy for users to differentiate which .txt files are parameter files.
       
       
       
       
15. There are two essential concepts to understand when working with the Revit Vault add-in.
    
    1. Using Revit Server or work shared central files – The Revit add-in does NOT require a check out. This behavior is unique and is unlike all other Vault add-ins where you must check a file out of the vault before you can modify it. Copies of the project file are added to Vault at specified milestones or automatically after a Revit Synchronization with Central.
    2. Note: Revit Server files and work shared central files can only be added to Vault using the Synchronize with Central command.
    3. Using Vault with non-shared project files – The project file can be downloaded using the Open from Vault command. This will automatically check out the file for editing. Once you are done editing the file, check the file back into the vault by using the Save to Vault command.
       
       
16.  Options:
    
    
    
17. For additional help, visit the Autodesk Vault Help webpage.