Screw and pin interaction

[Piccolo]

Hello, we are using your program to perform static simulations, so far it works very well with completely welded rigid elements. Today a different case occurred where I have a hole where a screw is inserted between the elements, I looked a lot and couldn’t find any fixing components for screws or pins. The question is how your program handles these interactions, how can I apply them? remembering that it is an interaction between components, not a fixed screw connection.

[FEAnalyst]

There are no predefined bolt connectors in PrePoMax. You could model the bolts as simple solids (cylinders) or using beam elements attached to the rest of the model via coupling/rigid body constraints but the latter approach requires keyword edits because beams and coupling constraints are not yet supported in PrePoMax. So the easiest way might be to tie cylinders there. Regardless of the chosen approach, you can even model pre-load using the pre-tension section.

On the forum, you will find multiple threads discussing various way of bolt modelling in PrePoMax. For example:

Modeling bolt connection with preloaded beam element

Hi everybody, it’s my first time here so i’d like, first, to say thank you to the people that are improving the software. I’m planning to test this software in some jobs where i’m using Ansys (some simple structures). The future objective is to use PrePoMax in the early stage of the design and Ansys only for the final checks. The software has almost all the needed features, the only thing that is missing is the design of bolt connections. I’m tryng to create the missing parts with the editor …

Best way to find force in bolted connection

[Screenshot 2024-02-12 082923] This connection is a part of a bigger assembly made of welded steel profiles. The two beams in the picture are supposed to be bolted together using two steel plates on the sides and 16 bolts. I already have the whole thing simulated in PrePoMax but now i wonder what the best way would be to find the force that needs to be held by the bolts. My first thought was to create a surface contact on the contact faces and then check the surface contact force with a his…

[synt]

bolt and weld is everywhere and commonly used, unfortunately only Catia and Ansys have this specific feature. Probably, both connector modeling approach still challenging.

[FEAnalyst]

@synt

unfortunately only Catia and Ansys have this specific feature

Not only, 3DExperience and SolidWorks Simulation also have bolt connectors. Fusion 360 too. Abaqus doesn’t but such predefined connections are more common in CAD-embedded FEA modules.

[synt]

interesting, is there any validation document for modeling approach of bolt and weld by Solidworks and Fusion including nonlinearity in boundary conditions (contact) and material maybe?

in modeling of bolt and weld, Catia or Ansys automatically generate spring and gap element, multi point constraint also.

[FEAnalyst]

Internally, the bolt connector available in SolidWorks Simulation is just a beam element and rigid links connecting it to the model. You can find some validation here: https://beacon-india.com/virtual-bolts-connectors-accurate-results-solidworks-simulation/

but also in the book “Analysis of Machine Elements Using SolidWorks Simulation” by S.S. Nudehi.

[synt]

even the bolt force prediction may sufficient., the simplest one using rigid links to connect will lead to lost in accuracy of result (stress and displacement) due to ignoring contact at bolt shank (body).