I want to perform a calculation via SW Simulation in order to check the strength of a bolt (screw/nut couple). I see 2 possible options to model this type of bond:
- Either I draw all the threads (screw side and nut side) in order to be able to do the calculation but it seems complex to me (as much to draw as to calculate).
- Either I model the parts to make it look as if they were together. This solution seems more appropriate to me but I am afraid of having results that are not representative of reality.
Does anyone have any advice on the most reliable/realistic way to proceed?
Simulation includes elements replacing screws (in imposed displacement/anchor bolts). It is roughly a beam element that is prestressed with a pre-tightening force (or torque) value. It's good for modeling a screw plating two parts for example.
It works in a lot of situations but it's not necessarily suitable in your case.
Modeling depends a lot on what you are looking for. If the problem to be solved is really the bolted connection, it is not the same as if we study a complete part with this connection locally (we can possibly simplify the model locally in this case).
Thank you for your feedback, but indeed in my case, I am trying to check the strength of the bolted connection so I cannot replace my assembly with another element...
Bolt connectors are a standard feature in simulation.
However, you need to add some information depending on your design.
If you have created your holes with the drilling function in SW, the diameters are automatically transferred to simulation, including and especially if you had countersunk heads.
If the stiffness of the bolt material is greater than the stiffness of the bolted parts, the adjusted shank option should be checked.
The bolt preload can be defined, either directly or as a torque (bolt suppliers give its values by universal codes). The value K = 0.2 is good for most cases.
A small precaution to take when you do a simulation with bolts, you must remove "global contact" for the two parts in contact. This makes it possible to check that neither of the two parts will be accidentally separated. With "global contact", it is the totality of the contacts between the two parts that is ensured as if there were a fusion in a single body. With "global contact" you will not see, for example, deformations in the event of a spill or any other movement that can twist the part at the height of the bolts.
One last tip when doing simulations on assemblies (considered as local assemblies), it is strongly recommended to simplify the simulation as much as possible by replacing the supporting parts with virtual walls, for example. This simplifies, among other things, the meshing and limits the artifacts of the second piece.
As you tell your message [[ Either I draw all the threads (screw side and nut side) ]], I also say on this forum that only the deformation of the part should be sought and never the solidity of the bolt whose technical characteristics correspond to very precise and international criteria of the ISO. This means that under no circumstances should a simulation be used to define the size of the screw between an M10 and an M12. The spirit of SolidWorks simulation is to focus only on the parts of your design and not on the standard screws and nuts, or the thickness of your sheets in relation to the screws.
I come back to your remark about the virtual wall.
As its name suggests, virtual means that it does not exist physically.
It's like in surface area, a surface is virtual and without thickness, etc...
The same goes for sketches that you use without realizing it with a virtual intersection that creates a sketch point at the point where two sketch entities virtually intersect. The dimensions and relationships of the virtual intersection point are retained even if the intersection itself no longer exists, such as when a corner is removed by fillet or chamfer.
The principle of the virtual wall is the same as when you do a remote charge. In this case you have a virtual point in the vacuum where the load will be applied.
Without going into too much detail, the virtual wall is a sliding support comparable to a plane support. However, you can specify a coefficient of friction and the elasticity of the wall.
(The texts say this:
Available for static studies only. This type of contact defines the contact between the entities in Set 1 and a virtual wall defined by a target plane.