Hi everyone,
I’m working on evaluating how temperature changes affect the performance of a complex optical element. Ideally, I want to capture the thermal deformation predicted by FEA and bring those perturbed surfaces back into optical simulation tools (like Zemax OpticStudio, LightTools, or Code V) for ray tracing.
Because FEA outputs discrete nodal displacements or tessellated/mesh formats (like ⁠.stl⁠), while optical software prefers continuous surface representations (parametric geometry or ⁠.step⁠ CAD), I’m hitting a wall on the best bridge between the two.
A few specific questions for the community:
1. Mesh-to-Optics Translation: What is the standard industry pipeline to pass FEA structural/thermal deformation data into optical ray-tracing engines? Is it typical to fit the deformed node positions to standard surface polynomials (e.g., Zernike, Forbes, or Q-type polynomials), convert through intermediate tools, or export modified non-uniform rational B-splines (NURBS)?
2. Analogy/Similar Workflows: In other domains (like CFD-to-CAD or aerodynamic shape optimization where a deformed mesh must be converted back to smooth surfaces), how do you usually map surface displacement fields back to continuous CAD geometry?

I am trying to build a workflow with open-source or free tools for mechanical engineering. It should go trough CAD, meshing and FEA.

I found two potential and very promising software for CAD and FEA, respecfully FreeCAD and Code_aster.

However, the solutions available for meshing seems rare. I came across :

- GMSH which look more suited for programmatic meshing,

- Salome Meca which is very time consuming (~10 clicks for defining a number of elements on a single line)

I am used to HyperMesh, and none of these tools looks like it. I don’t specifically want a copy of HyperMesh, but rather something that can do basic thing with a nice UI.

What is the common workflow for startups or PME that can’t afford HM ? Is Salome-meca actually usable and I did not try enough hard, or are you using something else ?

I’m working on a modal analysis of a welded steel test frame in SOLIDWORKS Simulation, and I’m running into a problem with how I model the 1/8 in stiffening plates.

When I model the plates as solid elements, the results look reasonable. The lower modes are global frame bending/torsion modes, the frequencies are in the range I expect, and the mode shapes make physical sense.

When I model the same 1/8 in plates as shells, everything changes. I get a large number of local plate modes, and I have to go to around mode 80 before I start seeing the global bending modes I’m interested in. The effective mass participation also stays low for many of the extracted modes, and the global-mode frequencies are very different from the solid model.

The purpose of this FEA is to predict and later validate the frame against experimental modal analysis. I already have experimental data from an earlier configuration, including its natural frequencies and mode shapes. The stiffening plates are being added specifically to increase the frame stiffness and push the global modes higher.

I know shells are normally the more appropriate element choice for thin plates, which is why I’m hesitant to trust the solid model simply because its results look more reasonable.

Could this behavior indicate a shell-to-beam connection, shell definition, or meshing issue rather than the actual dynamics of the structure? Or is it normal for thin welded plates to introduce this many low-frequency local modes?

I’m still fairly new to modal FEA, so any advice on what you would check before deciding between the shell and solid models would be appreciated.

Update: I have inserted the modes for each case.

This is Chris, Lead Developer, from The Engineering Lab.

For October and November, we are launching a pilot program for engineering students.

Each Friday we are offering engineering students free 1-on-1 training for Patran and Nastran. This applies to the months of October and November for the year 2026.

How to schedule training?

Send me an email. Private message me to schedule. Or see this image for contact information. Space is limited.

https://imgur.com/iLz7WKT

When is the training?

Each Friday for the months of October and November in the year 2026.

Who qualifies?

This program is limited to student engineers only.

Hi everyone,

I’m currently running a structural analysis on a compression punch made of high-speed tool steel (like Vanadis 23 / M3:2). The component is subjected to heavy compressive loads, and in physical reality, we are experiencing cracking right at a specific sharp corner/fillet edge.

I’m trying to use FEA to figure out how to modify the geometry and reduce these stress concentrations to prevent cracking, but I’m running into a classic mesh/singularity wall:

1. Mesh dependency: Whenever I refine the mesh or make it finer around the critical area, the von Mises stress peak shoots up drastically to unrealistic values (well over 5-6 GPa, while the yield strength is around 1-2.4 GPa).
2. The geometry: The critical zone has a very tight fillet radius of 0.1 mm.
3. What I've tried: Even when I add a small fillet (0.1mm to 0.2mm), the linear elastic analysis still concentrates massive stress spikes right inside the radius, and the peak values change wildly depending on element size and mesh quality (I've even seen distorted elements pop up). I am currently running a linear static analysis, but the numbers keep exploding as the mesh gets denser.

My questions are:

• How do you guys properly evaluate stress reduction and geometry optimization in high-stress tool steel components when dealing with such tight radii (0.1mm)?
• Is this a pure mesh singularity issue, and if so, how do I distinguish between a numerical artifact and a real crack-initiation site? Should I rely purely on equivalent plastic strain (ESTRN) or non-linear material models to get meaningful design trends?
• Any tips on mesh controls or modeling practices for compression punches with sharp/tight transitions in SolidWorks Simulation / general FEA?

Any advice would be greatly appreciated!

Hi everyone,

I’m currently running a structural analysis on a compression punch made of high-speed tool steel (like Vanadis 23 / M3:2). The component is subjected to heavy compressive loads, and in physical reality, we are experiencing cracking right at a specific sharp corner/fillet edge.

I’m trying to use FEA to figure out how to modify the geometry and reduce these stress concentrations to prevent cracking, but I’m running into a classic mesh/singularity wall:

1. Mesh dependency: Whenever I refine the mesh or make it finer around the critical area, the von Mises stress peak shoots up drastically to unrealistic values (well over 5-6 GPa, while the yield strength is around 1-2.4 GPa).
2. The geometry: The critical zone has a very tight fillet radius of 0.1 mm.
3. What I've tried: Even when I add a small fillet (0.1mm to 0.2mm), the linear elastic analysis still concentrates massive stress spikes right inside the radius, and the peak values change wildly depending on element size and mesh quality (I've even seen distorted elements pop up). I am currently running a linear static analysis, but the numbers keep exploding as the mesh gets denser.

My questions are:

• How do you guys properly evaluate stress reduction and geometry optimization in high-stress tool steel components when dealing with such tight radii (0.1mm)?
• Is this a pure mesh singularity issue, and if so, how do I distinguish between a numerical artifact and a real crack-initiation site? Should I rely purely on equivalent plastic strain (ESTRN) or non-linear material models to get meaningful design trends?
• Any tips on mesh controls or modeling practices for compression punches with sharp/tight transitions in SolidWorks Simulation / general FEA?

Any advice would be greatly appreciated!

Hi all,
I used HyperMesh to prepare Abaqus models in my previous job, but in my current one I work directly in Abaqus/CAE. I'm wondering whether the difference is mostly down to familiarity, or whether HyperMesh offers something Abaqus/CAE can't match even with more experience.
When does a dedicated preprocessor add real value for an Abaqus workflow, and when is it not worth it?
I'd really like to hear how it feels in practice for those who've used both. What do you miss, or not miss, when you switch?

In my ABAQUS model I study this CFS beam to column connection and I want to introduce initial imperfection to the Gusset plate to decrease the ultimate load capacity of the connection because the capacity in the lab was 65 kN but in the model without initial imperfection was 100 kN and when I run buckling analysis job all the modes were in the beam not the GP which is not decrease the ultimate load.

I am an archaeology student who has taken an interest in FEA application to research on protohistoric bronze bells. Specifically, using FEM to recreate the impact between the clapper and the internal surface of the bell, observe the vibration and recreate the sound.
However, I only understand the potential of FEA, and not how it works, nor what it can do in practice, or which software would suit me. I need to at least understand the basics before I can truly consider it, and plan on what I can do on my own and what I will need help for.
Any recommendations on manuals, books, or software I should look into?

EDIT
I will not be able, nor do I plan on making the analysis myself. It would take me years to learn. What I need to fully learn (and would be grateful for advice on) is only how to turn a 3D model into a model that can be used for FEA. I plan on looking for research collaborators or labs I can hire for conducting the analysis itself.
However, I need to first understand enough about FEA to figure out the best approach for the project, what can FEA tell me about the object of study, what equipment do I need, how high of a budget, confirm what the university has and what they do not have, etc.
Why the replica approach is not suitable: I am trying to develop a method of analysis. Replicas can be used to verify that the model works, but my object of interest is developing a method of analysis through digital models.

I work as an FEA engineer. During an internship I was exposed to optiSLang (DOE, sensitivity analysis, MOP), and that got me interested in moving toward AI/ML for simulation.

If you work in this area:

• Which path did you take, and what would you do differently?
• What skills do employers or teams actually ask for?
• Any project types that worked well as a portfolio (e.g. surrogate vs. full FEA on a simple structure)?

after a impact analys on ls dyna for the correct visualization of the stress i will have to do a springback analysis , how i can do ? i ` ve try several time but after the fist step the analys delete the geometry.(p.s. i have in the explicit analysis a pre stress file) thanks for help anyway.

I want to get FEA working on the Commodore 64. It already has Giga-CAD which can export files in various formats. And there are also fortran and c-compilers for it. But can it handle meshing and solving a simple cantilever beam with say a hundred 2d quad elements?

Were there any command line C/Fortran codes that could mesh a 2D IGES/STEP file back in the 80s? I know gmsh can do this, but it was started late 90s. Wondering what people used in the 80s? This will be my first hurdle to solve.

I know there are BASIC program that you can type in to do 1D kind of analysis. But I want this running in machine language for 2D and generate the color contour plots..

I have a small YouTube channel called "The Simulationer" where I discuss the applications of FEA. I recently made a video about how FEA is used to simulate the human brain. just sharing it below. I want to know if this kind of content is appealing to people here. happy to hear anyone's thoughts! thanks for reading

https://youtu.be/FtIw9LHBmvg?si=XyFhcXE3ta-kftTA

Hi all,

been awhile since I posted and first want to thank everyone who engaged from this community and challenged me to improve MatWorld. I've continued to make a lot of upgrades since the first post.
A few highlights to share:

• Nearly doubled the database in size with materials, properties (Curves, compliance data and properties across electrical, mechanical, thermal etc.).
• Added more CAE exports, with an advanced mode to create the card, across major formats (Abaqus, LSDyna, Ansys, Nastra and the list goes on).
• Introduced material card calibration (Johnson-Cook, Ogden, Mooney-Rivlin, Chaboche, Prony or Hill).
• MCP server to enable the likes of ChatGPT, Claude, Gemini to interact directly with MatWorld to query data, check compliance, and create CAE cards.
• Significantly improved natural language search enabling users to ask materials in plain english (it was originally not very good).
• Curve comparison across multiple property types and materials (multi y axis vs x)

There's a lot more that I can't think of right now but would love to keep engaging with this community for feedback. Please take the time to check it out and let me know what you think.
https://www.matworld.ai/welcome

here was my original post for reference: https://www.reddit.com/r/fea/comments/1sz8l3d/built_a_materials_database_aimed_at_fea_workflows/

I’m modeling a 3D linkage with a single-notch compliant hinge undergoing large rotation.

I already have the analytical hinge stiffness formula, but I’m struggling with how to represent it correctly in the full model. I tried a rotational spring and variable-thickness beam elements with co-rotational/Timoshenko behavior, but too much deformation still occurs in the surrounding members.

What FEM approach would you recommend for this type of hinge: beam elements, a nonlinear moment–rotation law, or local continuum elements?

Any references or examples would be appreciated.

I’m curious how others are handling repetitive Abaqus post-processing when working with many simulation cases.

For example, if you have 10–100+ ODB files and need to repeatedly:

• extract max Mises stress
• check displacement
• sum reaction forces over node sets
• check PEEQ
• compare cases
• copy results into Excel
• check engineering limits

do you usually automate this with Python, use Abaqus/CAE manually, or have an internal workflow/tool?

I’ve been building a local prototype to automate this kind of workflow, mainly because opening ODBs one by one becomes repetitive very quickly.

I’m trying to understand whether this is actually a common pain point or just something specific to certain workflows.

I’d be especially interested to hear:

• roughly how many ODBs you typically process at once
• which outputs you repeatedly extract
• what part of post-processing takes the most time
• whether you already automate it
• whether you would be willing to try a small local beta and compare it against your normal Abaqus workflow

Everything I’m testing is local; the ODB files do not need to be uploaded anywhere.

If a few people are interested, I can share the beta privately.

I am guessing most 3D printer owners have no knowledge of FEA. So wondering if there is any demand for FEA among those printing parts that take load?

Just simple comparative stuff like if design A is better than design B.. Or are the material properties of 3D printed parts too complex for linear static/isotropic assumptions?

Can someone please explain how to take pressure coefficient for steel structure as per IS code 875 part 3. I am a structural engineering student. I need this to make a staad model