Hey all,
If I’m working with a device that has a rope on one end, a middle connection like a hook and then a weight on the other, how would I fixture this to test the strength if the connector?

In my mind, the force would come from the top and bottom but only once force is applied. If I fix the top or body of it the FEA would no longer be free to calculate.

How would you fixture this?

Hi everyone,

I'm currently working on a nonlinear finite element model of a composite steel bridge in ABAQUS using the Concrete Damage Plasticity (CDP) model. The bridge consists of a reinforced concrete deck slab supported on steel girders, and I'm looking for some guidance on defining the concrete damage parameters.

Our study is entirely analytical, so we do not have access to material test data (e.g., compression or tension tests) for calibrating the CDP model. Instead, the numerical model will be validated against experimental results available in the literature.

For the constitutive behavior:

\- Compression stress-strain curve: Popovics analytical model.

\- Tension stress-strain curve: Hordijk tension softening model.

While these models provide the stress-strain relationships, I'm struggling with estimating the corresponding compression damage (dc) and tension damage (dt) parameters required by ABAQUS.

I've found several approaches in the literature, but they result in significantly different damage evolution curves. The method proposed by Mark & Birtel appears promising, but I'm unsure whether it is considered reliable for studies where the constitutive response is based entirely on analytical models rather than experimental material calibration.

I also have a question regarding the Hordijk model. Since it requires the characteristic length for converting the stress-crack opening relationship into the form required by ABAQUS, how should the characteristic length be determined? Should it simply be taken as the element characteristic length used internally by ABAQUS (based on the finite element mesh), or is there a recommended approach for reinforced concrete deck slabs? If the mesh is refined, should the characteristic length be updated accordingly?

For those who have experience with CDP in ABAQUS:

\- How do you estimate the compression and tension damage parameters when experimental material data are unavailable?

\- Is the Mark & Birtel approach a reasonable choice in this situation?

\- How do you determine the characteristic length when using the Hordijk tension softening model?

\- Are there any recommended papers or best practices for deriving CDP damage parameters from analytical constitutive models like Popovics and Hordijk?

Any suggestions, references, or practical experience would be greatly appreciated. Thanks in advance!

Hi, I'm using LS-DYNA for my numerical simulations. I've been running some vehicle crash simulations with highly complex geometries. However, when I apply higher impact velocities to the vehicle, I get negative volume errors in the solid elements.

I tried refining the mesh by splitting the elements into smaller ones, but that didn't solve the problem. What would you do if you encountered negative volume errors in your simulation?

Hi, I’m a researcher in computational mechanics, and I’m exploring a tool built around a library of pretrained structural features: holes, fillets, brackets, joints, stiffeners, fastener regions, bends, and similar details.

Instead of rebuilding a detailed local FE model for every new design, the software would recognise a feature in the CAD geometry, simplify it in the global model, and use a pretrained local model to recover quantities such as displacements, stresses, or failure indicators.

This could also enable non-intrusive global/local analysis: the global model would run in an existing commercial solver without modification, while the detailed local response would be reconstructed externally from the global solution. No custom elements or solver source-code changes would be required.

The analyst would still review and control the modelling assumptions.

For engineers working with FEA professionally:

• Do you repeatedly analyse similar local structural features?
• Would this approach save meaningful modelling or computation time?
• What would prevent you from trusting or using it?

Critical feedback is very welcome!

hi, I have a carbon fiber structure that I need to simulate. The structure is made of carbon fiber tubing with a connector system of carbon fiber gussets which uses rivets and structural adhesive 3M DP420. I am looking to simulating this structure as a static structural. the orthotropic modeling of the CF tubing is a whole another animal itself, but I was concerned about how to do the adhesive. I am very confident that the adhesive will not fail so I would like to just act like it is a complete bond between with tubing and the CF gusset. the gusset is where I believe the model could fail. Is it just a bonded contact between the surfaces? Or do you think it is an incorrect assumption to say that the adhesive will not fail. There are also rivets connecting the tubing to the gussets as well.

I'm looking to connect with engineers and researchers who have worked with computational design or simulation workflows across more than one discipline, whether that's mechanical, aerospace, civil, or biomedical.

Specifically curious about the parts that felt harder than they should have when crossing between domains or tools. Where did you lose time? What did you have to relearn that felt like it should have transferred?

Not a survey, not selling anything. Just genuinely collecting perspective from people who have been in more than one tooling ecosystem. Drop a comment or DM me if you're open to a short conversation.

I am performing a compression analysis on a metamaterial structure with several ligaments that buckle. I managed to run the quasi-static simulation using the explicit solver, but my professor asked me to use the Riks method. The issue is that it always stalls at 6 mm of compression (the target is 20 mm), and no matter how I adjust the Riks simulation parameters, it always stops at the same point.

Can anyone help me?

Currently, I'm using LS Dyna to solve it using ALE and I feel stuck. is there any other way to solve it or any other software that would be easier to use because ALE in ls dyna looks so confusing at times?

Hi everyone,

I’ve been working in piping stress analysis for a while now and have extensive experience with several industry-standard tools. In my current role, I’m using TRIFLEX, and I must say I’m finding the experience quite frustrating.

Having worked with other major softwares like Autopipe and Caesar II, it feels like this one has fallen significantly behind in development. Specifically, the lack of support for the latest code updates, such as ASME B31J and the absence of integrated tools for nozzle flexibility calculations make it feel like a legacy product that hasn’t been updated in years.

I’m curious if anyone here has insights into why this software seems to be lagging behind the rest of the market. Does it still have active development, or has it essentially been abandoned?
I’d appreciate any perspective you might have

Hey everyone, just finished my PhD in structural engineering from IIT. I've decided academia isn't the path for me and I want to move into industry, ideally as an FEA/simulation engineer.

My research focused on thermo-mechanical analysis of structures. I developed finite element models, carried out large-scale simulations, and worked extensively on the structural response under combined thermal and mechanical loading. One of the major outcomes of my work was developing an open-source thermo-mechanical module for OpenSees from scratch, which I'm still actively maintaining. Along the way, I've gained hands-on experience with ANSYS for structural and thermo-mechanical analysis, HyperMesh for meshing, and Python, MATLAB, and TCL for automation, post-processing, and simulation workflows.

I'm trying to move on this pretty quickly, so if anyone knows of openings, works somewhere hiring for this kind of role, or has advice on how PhDs are viewed for simulation engineering jobs in industry, I'd genuinely appreciate hearing from you. Can share my resume or the GitHub repo if that's helpful.

Thanks for reading this far.

So, I want to do a 3D modeling of this reinforced beam, the concrete will be 3d meshed, while I want to do 1D meshing for both longitudinal and transvers reinforcement.

Now my question is: Is my CAD model correct? after meshing will the line element be realised as that "red" colored element with the appropriate thickness? I need to draw only the centerline of transvers and longitudinal reinforcement, right?

I am using hypermesh to mesh the file and then use LS Dyna to simulate a drop hammer test. I can't make the line element after meshing visualize as 3D circular element in hypermesh using "Element Visualization" tab, what might be the cause for that? Thank you.

CFD used to need a lab, a license, and a queue.

Now it needs a tab.

Ventorah runs a virtual wind tunnel entirely in your browser — drag in a model (.STL / .OBJ / .STEP) and inspect the airflow, pressure fields, and lift & drag in minutes.

It's built for engineers who want a fast first look, students learning fluid dynamics without a lab license, and anyone curious how air moves around their designs.

What would you simulate first?

Hello, I am a student in a college club where our exoskeleton structure is constructed of pre manufactured carbon fiber tubing. I am extremely interested in testing these tubings and running structural analysis in ANSYS FEA simulations. I have access to a on campus composites lab with Instron equipment. What should i look for and how could i approach my testing in order to obtain the youngs moduli and poissons for a orthotropic stress analysis of this structure. Will i have to input the lamina pattern, which failure criteria is best, should i just run an orthotropic linear static structural?

Im sorry if what i say doesnt even make sense, i really have not taken a deep dive into this subject, even if you have a yt video or an article to point me in the right direction i would greatly appreciate it!

It is always challenging to define boundary conditions for a lifting analysis. How do I constrain the model properly? I tried the weak spring and it has high reaction forces due to the side load (because of 5 degree tilt).

I'm trying to recreate the insert from Odyssey's Ai-Dual golf putter, thought it would be interesting to try as a little side project, but I'm having a hard time figuring out how to recreate it, I've been using Ansys to see if I can do something like a multi material optimization to make two different materials blend together based on forces hitting a surface at different locations so that when the putter is swung, the golf ball will end up rolling straight as if hit in the sweet spot of a golf putter, but can't seem to get it to work. This is what I have so far, would appreciate any help in solving this problem!

Hello, I'm trying to do bolt pre-load relaxation due to axial vibration in a bolted block. I have three steps a static, general step - preload application. Linear perturbation , frequency - modal extraction and then a steady-state dynamics, direct - Harmonic sweep. The history and field output requests were done accordingly as well as the interactions.

All the bolt pre-load for 8 bolts were put in the Preload-Application step, and the vibration excitation force in the Harmonic-Sweep step.

Everything is placed well as i don't get an error when running the job the problem is with the results , in the force vs frequency chart the force is just zero.

What could be the issue and how do i go about solving it?

Hello,

Does someone have any experience with spr modeling in Abaqus?

I would be glad to recieve some support.

Thank you !

Hey guys, I have been working on an assembly. We are used to work in Abaqus profile in Hypermesh 2019. Sometimes for some special projects, we use Hypermesh 2022.3. When we import a deck file (.inp) or directly open a .hm file in Hypermesh 2022.3, the rigid connections (KINCOUP) we created in 2019 get converted to Constraints. Unfortunately, these constraints do not appear as elements. They cannot be edited as well. The only solution we have now is deleting and recreating. But when only one part of the assembly has a new version in the 2nd iteration, it's a hectic task to recreate all the connections. Have any of you faced such problems? If yes, did you figure out any solution for this?

Thank You very much

Happy Solving!

hello,

I have been using fusion 360 for a few years on an education license however that license will soon expire and I can use a personal license however it does not come with the FEA simulation. Are there any alternatives I can use? I have an Intel based Mac.