Everything is open (code MIT, data/CAD/reports CC BY 4.0): https://github.com/Shass27/curiosity-perseverance-wheel-fea

We're a team of four engineering students, and we've been looking at the wheel-skin damage on NASA/JPL's Curiosity rover as project for our Solid Mechanics course: the thin aluminium skin cracked and punctured on sharp rocks. Perseverance went to a thicker skin and a different grouser pattern, so we tried to put numbers on how much that actually helps and a develop a surrogate fea model for academic purposes

What we did

• Hand calc vs FEA: a flat skin segment between two grousers, modelled as a fixed stepped beam with a Peterson Kt, compared against an Ansys solid model along a surface path.
• Batch FEA: 458 linear-static Ansys 2025 R1 cases on a curved R250 wheel panel (Al 7075-T7351, ends fixed). The rock is a 300 N pressure load on a circular patch. We swept 5 grouser patterns, 2 skin thicknesses (2 / 7.5 mm), 3 grouser angles, 3 fillet radii and 5 patch radii. The whole batch was driven by a Workbench journal script.
• ML surrogate: each stress/strain field is gridded onto a common map, compressed with PCA (40 modes) and learnt with Gaussian-process regression, plus a separate GP for the peak value with a 95% band. It's wrapped in a MATLAB GUI that shows the nearest real FEA case side by side.

Results

• Full write-ups: Failure analysis (PDF) · Surrogate model (PDF)
• ML model: on fully unseen geometries, 3.1% median peak-stress error, R² = 0.993, and 94% coverage by the 95% band.
• GUI: pick a feature, thickness, angle, fillet, rock size and load, and it shows the predicted stress/strain maps next to the nearest real FEA case. Every input is flagged as sampled, interpolated or out of range. It warns at the fatigue limit, failure strain and yield, and exports the predicted field in the same format as the Ansys output.

Why we're posting

We'd like to write this up as a paper, and we'd value any critique before we do: modelling assumptions, what a reviewer would attack first, missing validation, or whether the surrogate approach is reasonable for ~440 cases. Feel free to criticise or give feedback

Everything is open (code MIT, data/CAD/reports CC BY 4.0): https://github.com/Shass27/curiosity-perseverance-wheel-fea

Both reports are linked as PDFs in the README.

Hello, I would like to ask how do you keep order in each FEA project?

Currently i feel like when Iam starting project i try to document everything, but later in Iam all over the place. Hundreds tabs open in browser, Multiple result files from each sensitivity study with odd meaning (after week you have no idea what that means)

I would like to become better at documenting my steps (for example, currently looking for materials) create material library for all materials with sources.

Are you using some special tool for this or just properly structured Excel with links to folders?

Thank you

hello guys , recently for better use of ls dyna i downloaded the manual, it`s very massive over 4000 pages (the vol I). My intention is create a sistem ai based where you can load the manual and after that you can ask how to do the task, a sort of tailored tutorial. it's a good idea ? i think i start to a project on claude . maybe there is a better system . If you have any insights, they would be appreciated.

Hi everyone,

I’m comparing a Python analytical global buckling model with an Abaqus shell FE model of a composite stiffened panel, as part of a sensitivity study covering different geometries and layups.

The FE model often produces many local skin or stringer buckling modes before a global panel mode appears. The global mode’s index changes between cases, so I can’t consistently compare the same numbered mode. Manually inspecting every mode across the entire study would also be quite time-consuming.

How do others handle this? Is there an established way to identify and track global buckling modes automatically, especially when local and global deformations are mixed?

Any practical experience, Abaqus workflows, or relevant references would be appreciated!

Assalamu Alaikum everyone,

​I am an independent researcher exploring high-pressure supersonic closed-loop fluid dynamics. I am looking to connect with a simulation expert who has access to CFD tools to discuss and test a kinetic-to-electrical energy conversion module under strict confidentiality. If anyone is interested, please DM me.

I conducted an external flow simulation of a robot and want to conduct load transfer for structural analysis. I am currently using Altair Hypermesh CFD and would like to ask how to export the load results for structural analysis. No tutorials in the internet would like some advice thank you.

Hi everyone!

I'm a mechanical engineering student working on a semester project about all-solid-state batteries, specifically the mechanical behaviour of cracks associated with lithium dendrite penetration in garnet-type solid electrolytes.

I'm looking for feedback from people with experience in fracture mechanics, finite-element modelling, solid electrolytes, or computational materials science. I'd appreciate honest criticism, especially if my idea is poorly scoped or if there's a simpler, more defensible approach.

Background and the problem

My professor pointed out that the general idea of deflecting dendrite-associated cracks using engineered defects has already been investigated. They asked me to compare my proposal with existing work and explain what my study would actually contribute.

One particularly relevant paper is:

• Zhang et al., Mechanically driven Li dendrite penetration in garnet solid electrolyte, Nature (2026): https://www.nature.com/articles/s41586-026-10415-9

My understanding is that the paper investigates mechanically driven lithium-dendrite penetration and reports that defect geometry can influence the propagation path. I still need to examine the supplementary information carefully before concluding whether my proposed parameter study has already been done.

My proposed project

Rather than claiming that void-induced crack deflection is a new discovery, I am considering a small, comparative 2D mechanical simulation in COMSOL.

The tentative research question is:

In a 20 µm-thick garnet electrolyte film, how does the depth of a buried, transverse flat void affect the stress field and the potential crack-deflection tendency, compared with a reference configuration and a circular void?

My initial plan is:

• Case A: no void — reference configuration.
• Case B: circular void.
• Case C: transverse, flat void at three different positions through the film.

The preliminary geometry uses a 5 µm surface-connected crack, a 5 µm-long void and a 0.5 µm void thickness. These are starting assumptions, not validated optimal dimensions.

For the first stage, I was planning to use 2D plane strain and linear elasticity, with provisional values of (E = 150) GPa and (\nu = 0.25). I was also considering a crack-face pressure of 150 MPa, with 600 MPa as a possible sensitivity case. I understand that crack-face pressure, external stack pressure, and hydrostatic stress in confined lithium are different quantities, so I need to justify the loading conditions carefully.

The initial outputs would be stress distributions around the crack tip and void, followed—if feasible—by fracture-mechanics quantities such as stress-intensity factors or a suitable crack-kink criterion.

I would not claim that a static elastic model proves actual dendrite deflection or prevents battery short circuits.

Questions I'd appreciate help with

1. Prior art: Has the effect of the position or depth of a transverse void on crack deflection in a thin garnet electrolyte already been studied? Which search terms, papers, or supplementary materials should I investigate?
2. Research contribution: If the general mechanism is already known, would a carefully defined parametric comparison of void position and shape be a reasonable student project? Or is there a more useful and manageable research question?
3. Model geometry: Is a 2D plane-strain model a reasonable starting point for a 20 µm garnet film with a surface-connected crack, or are there important limitations I should address first?
4. Fracture mechanics: Would you recommend starting with linear-elastic stress analysis and then extracting (K_I), (K_{II}), or the J-integral? Is there a suitable criterion for estimating the initial crack-kink direction in this situation?
5. Loading and material properties: Are the proposed pressure scenarios and provisional material properties defensible starting assumptions? What should I verify before using them?
6. Numerical reliability: What would be the minimum sensible mesh-convergence and boundary-sensitivity checks for a student-level model like this?
7. Scope: If you were supervising this project, what would you keep in the core deliverable, and what would you leave as an extension?

Another potentially relevant paper is Garnet-Based Solid-State Li Batteries with High-Surface-Area Porous LLZO Membranes (ACS Applied Materials & Interfaces, 2024): https://pubs.acs.org/doi/10.1021/acsami.3c14422

I understand that porous membranes designed to improve interfacial contact are not necessarily equivalent to engineered transverse voids intended to alter crack propagation, but I would appreciate suggestions for other relevant comparisons.

Thanks in advance! I'm especially interested in constructive criticism, useful references, and advice on how to make the project more rigorous without making it too ambitious for a semester.

While analysing safety factor in composite failure tool should I look at the minimal value on the left (0,94) or is it some numerical abomination on a node and I should beeter look at a whole elements and say in this specific simulation my safety factor is around 1.4?

Hey solidgangs! I have a question. I have a personal project where I designed a VAWT (wind turbine) and I want to optimize some parameters based on my actual measured wind speed (average wind speed/wind velocity) in our place. My problem is how can we get the RPM and torque of the turbine prior in doing the flow simulation. What are your suggestions or approach on this kind of project.

I'm conducting a simulation in Explicit Dynamics where a sample is compressed between two rigid plates. I want to specify the coefficient of friction for the plate-sample interaction as 0.2 and the sample self contact as 0.25. I tried many things: specifying manual contacts, body interactions and combinations of both, but it gives me an error saying some parts having inconsistent values for coefficient of friction.

Could someone please guide me?

For use of EMerge I have been busy with a Sparse Direct solver that works on both Apple Silicon GPUs, AMD and also Nvidea.

Downside is that its single precision with some iterative refinement options which may be an issue for some physics situations (nearly singular matrices)

Its currently the fastest sparse direct solver option for Apple Silicon and measures up well against CuDSS.

It does Float and Complex valued solves and uses a custom multi-threaded Nested Dissection implementation. Perhaps some will find it helpful here who are doing bespoke FEM simulations.

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 ?

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!

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?

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 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)?

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..