I am using inventor 2025 with Nastran. When I make a simple part, say a cylinder and then go to the nastran environment it will mesh fine. If I then go back and add a feature to the original cylinder I cannot get it to mesh. The feature I added will not mesh. If I highlight that feature in Nastran and try to apply an idealization to it I get notes saying I am making duplicate idealizations and it still won't mesh. Is it possible to do that? If so, how? Show More

Webinar below shows different methods to size welds: https://www.youtube.com/watch?v=K6MPCb6V02M   There are basically two different groups of methods shown: one that doesn't require the weld to be explicilty modeled, and other that requires the weld to be modeled in the FEA.   Modeling welds in FEA is prone to problems due to mesh density sensitivity and singularities. It's also impossible to do so for complex structures in aerospace, naval, big industrial plants. The webinar also shows a method that doesn't require the weld to be modeled. It is Weaver's Traction Stress Method. This has been shown to be inaccurate. I went through the webinar and several articles, and I can say with confidence that the software is currently outdated when it comes to weldment analysis. There are different processes for weld sizing, but the main methodologies are:   - Blodgett's Method (Handcalc): Uses analytical solutions to calculate the weld from elementary mechanics. It predates FEA analysis and doesn't account for local flexibility, eccentric stiffness, stress concentration, load distribution, complex geometries.   - Weaver's Traction Stress Method ((https://www.weavereng.com/feweld/dload/FEWeld_WhitePaper.pdf): Uses FEA and the traction stress state to calculate the weld. But the method is still sensitive to singularities and mesh density, and doesn't account for the local effect of the weld because it's not modeled in the FEA analysis. This has been proved to result in significant errors.   Also, the methods above assume the resisting throat is at 45°. This has been shown to be incorrect for welds with high shear loads in the longitudinal direction.   - Explicit Weld Modeling: Uses FEA with the weld modeled. It's prone to problems due to mesh density sensitivity and singularities, that cause peak stresses in the weldment that are not real.   All of these have been improved in Dong's Traction Stress Method (https://backend.production.deepblue-documents.lib.umich.edu/server/api/core/bitstreams/493b8549-b9c3...). This is the state-of-the-art, and the major improvements are:   - It's not significantly affected by singularities, which is a common problem for analyzing welds when they're modeled in the FEA. - In the publication above he created a fillet weld element for FEA that eliminates the hassle of modeling welds in the FEA, while the element itself still retains the structural effect as if the weld was there. - His method accounts for the fact that weld failure changes from 45° to 22.5° depending on the loading condition.   The difference is significant. I have been able to eliminate weld distortion problems and save a lot of money just because I'm not oversizing my welds anymore, which is what the old methods do.   Unfortunately, to use it in Inventor Nastran in its current configuration, I have to explicitly model the weld. But the article above shows the formulation for a weld element that eliminates the need to do this. My suggestion is to implement it in Inventor Nastran so weld sizing can be done properly. Show More

Creating a specialized module within the Inventor Nastran environment for end-to-end simulation of welding processes. This module will allow engineers to predict residual stresses, welding distortion (warpage), and the Heat-Affected Zone (HAZ) without the need to export geometry to third-party software. Show More

In InventorNastran's thermal stress coupled analysis, I would like an alert message to be displayed if the initial temperature is not set. Currently, the calculation is performed without any message even if the initial temperature is not set, which can lead to incorrect results being taken for granted. *This issue has been reported to Autodesk support in Japan (case_No. 25493022). Show More

In Inventor Nastran's thermal stress coupled analysis, I would like an error (or alert) message to be output if the element order used in the heat conduction analysis is different from the element order used in the stress analysis. Currently, even if the element orders are different (for example, if the element order used in the stress analysis is accidentally changed), the calculation is carried out without any message, which can lead to incorrect results being taken for granted. *This issue has been reported to Autodesk Japan Support (case_No. 25488122). Show More

I would like to add shell elements that can set front and back boundary conditions and calculate temperature gradients through the thickness in Inventor Nastran heat conduction analysis and thermal stress coupled analysis. *This issue has been reported to Autodesk support in Japan (case_No. 25493019). Show More

Hi, The percent modal effective mass is so useful and important in so many analyses in Inventor. Why do you force the user to dig through folders, open a file, type “P E R C” (otherwise it doesn’t even show up in the search), and only then try to make sense of the results? And if you run another analysis, you have to start all over again. That’s assuming you even know where to look—most users don’t even know this option exists. Please. Put these tables directly in the results, accessible with a single click. Come on, guys. Show More

I'm having trouble automatically generating contact surfaces for shell and solid contact issues. Specifically, even when I set the Contact Data Tolerance value in Options to a value greater than the clearance between the shell and solid, the contact surface is not automatically extracted. I contacted Autodesk support in Japan about this issue, and they told me, "There should be a function to automatically generate contact surfaces between shells and solids, but this issue has been occurring since around version 2016." I hope for an immediate improvement or fix. Show More

Howdy all! In my models, I typically use beam elements and RBE2/RBE3 connectors to simulate bolts. Everything starts off smoothly, especially with the initial free-free modal analysis, which is always the first step. However, I’ve been running into a recurring issue where these connectors randomly lose their connection after performing the modal analysis a few times — no rhyme, no reason. I find the simplest thing throws them off, like adapting Bolt No:30 will break the connection on Bolt No:06. Now, if we’re only dealing with a few bolts, it’s manageable (if you have the patience), but when you’re working with 30+ bolts in a model, this becomes a pretty hefty pickle to swallow. After poking around in the Inventor Nastran forums, it looks like I’m not the only one facing this. Others have mentioned similar issues, which makes me think it might be time for a closer look at the RBE2/RBE3 connector behavior - make them more robust and reliable - Show More

Hi We would like to be able to use the graphs created and be able to personalize it      -  change the axis name      - use value...etc..     and of course, being able to export it Excel or any equivalent tool Alain Show More

I find the meshing table a bit difficult to use as well as confusing at times. When using the meshing table I have noticed that sometimes it works, but most of the time it doesn't. Meshing failure? Okay, let's trouble shoot. The dialogue box indicates no problems found. So where does this leave the user? Is the issue with the element size, type, meshing settings, tolerance value? If this can be more clear and concise, with the meshing table made more robust and reliable it would be great Show More

Bolts.... Probably the singular most common cause of divergence in non-linear analysis, not to mention the tremendous doubt it can instill in you. Currently bolts can not be analyzed separately within an analysis. What is required is the ability to analyze the bolts in subcase 1 (without a dummy load) and then carry those results over to other subcases. That will be the most accurate reflection of a real world scenario. Show More

I find the dialogue box for creating loads on multiple entities confusing and unclear, particularly when the dialogue is not consistent. I have seen a few people asking the same question, and I see answers of varying clarity and correctness. The problem is: I create a load of 100N, and select 2 faces. Do I then apply 50+50N, or do I apply 100+100N ? The rest is maybe best explained by the enclosed picture.   Show More

When trying to delete contact conditions that you've created, the operations and expressions differ depending on whether you created the contact conditions "automatically" or "manually." I'd like this to be standardized. When you create a contact condition "manually," you can right-click the contact condition you want to delete and a delete button will appear, but when you create a contact condition "automatically," you have to press the Delete key on the keyboard to delete it. Show More

When trying to delete contact conditions that you've created, the operations and expressions differ depending on whether you created the contact conditions "automatically" or "manually." I'd like this to be standardized.   When you create a contact condition "manually," you can right-click the contact condition you want to delete and a delete button will appear, but when you create a contact condition "automatically," you have to press the Delete key on the keyboard to delete it. Show More

I would like to be able to specify and change the Y-axis range (min/max) and number of divisions for XY-PLOT. Show More

In Inventor Nastran, the element coordinate system Z direction (normal direction) of shell elements can be displayed and checked, but I would like to be able to display and check the XY directions as well. Show More

I would like to be able to select multiple idealizations with a ctl+click then right click to get the display toggle option to be able to hide/display multiple idealizations at once.   Currently when multiple idealizations are selected the display toggle option is not available in the right click context menu. This is true even if the two idealizations are of the same display state.   With a large FEA each one of these display/hide toggles requires a long time for the view to update. If multiple idealizations could be done with one toggle it would greatly reduce the time waiting on the view to update if the display state was updated for each idealization prior to displaying the results.   Show More

Hi, As FEMAP Nastran users, they require the ability to intercept nodes in RB2 RB3 beams and then connect them, for example, with rigid connectors. This makes it easier to study beam structures where I currently cannot divide sections unless I operate in the 3D model  with 2 beams instead of 1.   Show More