# Butt and Lap Join ( welding analysis) **URL:** \ **Category:** General Questions\ **Created:** [September 1, 2025, 7:29am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942 "2025-09-01T07:29:59Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 1, 2025, 7:29am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/1 "2025-09-01T07:29:59Z")
Dear All, Can you guys please guide us on how to run Butt and Lap Joint ( welding analysis) i.e. how to build the model?. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 1, 2025, 7:36am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/2 "2025-09-01T07:36:39Z")
Do you mean analyzing the strength of a ready-made welded joint or simulating the welding process ? ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 1, 2025, 8:01am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/3 "2025-09-01T08:01:55Z")
we want to simulate and run fea analysis for butt and lap joint. After that we will physically build the units and we will test them to co- relate the results. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 1, 2025, 8:10am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/4 "2025-09-01T08:10:32Z")
So you want both - simulation of the welding process (weld being built during the simulation) and then strength analysis of the formed weld ? The latter is easy (here’s an example: [CalculiX-Examples/Thermal/Thermal distortion at master · calculix/CalculiX-Examples · GitHub](https://github.com/calculix/CalculiX-Examples/tree/master/Thermal/Thermal%20distortion)) but the former is tricky because CalculiX doesn’t have built-in features for that and workarounds are necessary to simulate the welding process. You can find some helpful resources on the CalculiX forum where this topic has been discussed a few times in the past. For example: [Welding analysis with DFLUX - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).](https://calculix.discourse.group/t/welding-analysis-with-dflux/1435) ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 1, 2025, 8:51am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/5 "2025-09-01T08:51:41Z")
Well for butt and lap joins which constraints can we use please?. Or not recommended as they may poduce wrong results?. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 1, 2025, 9:05am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/6 "2025-09-01T09:05:12Z")
There are several ways. Sometimes the mesh is made continuous and there are no constraints to avoid spurious stress concentrations. Often there are tie constraints and contact. With well matched meshes it shouldn’t be a problem. You will find a comparison of the different approaches here: [Modeling Welds for Finite Element Analysis (FEA) | Apollo Engineering](https://apolloedge.com/2018/07/19/model-welds-for-finite-element-analysis-fea/) ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 3, 2025, 8:12am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/7 "2025-09-03T08:12:42Z")
Thanks a lot. We created simple parts, joined the parts( in freecad) using boolean operation, and built the model( attached). Do you believe we can co-relate( with less error and certanity) the above results to butt welding results ?. > **[temp10.pmx - Shared via TeraBox](https://1024terabox.com/s/16P2pVkYFM5bZ55uXsK3MdA)** > > TeraBox offers up to 1024GB of free cloud storage. Download the app for secure storage and file sharing anytime, anywhere. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 3, 2025, 8:16am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/8 "2025-09-03T08:16:21Z")
I can’t download it without having to register on that website. Could you use a different hosting service like e.g. WeTransfer ? ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 3, 2025, 8:24am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/9 "2025-09-03T08:24:33Z")
Please share ur email id ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 3, 2025, 8:25am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/10 "2025-09-03T08:25:32Z")
> **[temp10.pmx](https://wetransfer.com/downloads/65128314e888fadf9d80264eb14fdd7420250903082501/896405?t_exp=1757147101&t_lsid=a7a7f8dc-68e3-4f26-8539-f7d79daa3630&t_network=link&t_rid=Z29vZ2xlLW9hdXRoMnwxMTYzOTA2NzMwMjkyNjIyNTA3MTQ=&t_s=download_link&t_ts=1756887901)** > > 1 file sent via WeTransfer, the simplest way to send your files around the world ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 3, 2025, 8:31am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/11 "2025-09-03T08:31:20Z")
Ok, I can download it now. If you want to get more accurate results in the weld area: ![image](https://global.discourse-cdn.com/free1/uploads/prepomax/original/2X/6/650c19e9b5d05f51cf497c4ee961551791780a25.jpeg) then apart from further refining the mesh locally in this global model, you can also use the submodeling technique: [https://www.youtube.com/watch?v=RNVE1rk1yps](https://www.youtube.com/watch?v=RNVE1rk1yps) and analyze only a small segment of the joint with a finer mesh. This is commonly used for weld assessments. ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 3, 2025, 8:36am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/12 "2025-09-03T08:36:54Z")
Great . In principle, you are ok with our approach right.. ---
**Author:** ![design](https://avatars.discourse-cdn.com/v4/letter/d/b5a626/32.png) [@design](https://prepomax.discourse.group/u/design)\ **Post date:** [September 3, 2025, 9:03am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/13 "2025-09-03T09:03:10Z")
Further, any example on how to run an impact analysis please. ---
**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Post date:** [September 3, 2025, 9:20am UTC](https://prepomax.discourse.group/t/butt-and-lap-join-welding-analysis/2942/14 "2025-09-03T09:20:59Z")
> [@design](#): > > In principle, you are ok with our approach right.. As long as you include the geometry of the weld (either merged with the welded parts or tied to them), it should work with a sufficiently refined mesh. The aforementioned article nicely shows which way may provide better results. > [@design](#): > > Further, any example on how to run an impact analysis please. CalculiX (unlike e.g. OpenRadioss) is not really good for that, you may encounter several limitations. But you can try with implicit or explicit dynamics: [https://www.youtube.com/watch?v=-X0Shj7UXE0](https://www.youtube.com/watch?v=-X0Shj7UXE0)