If anyone has looked into the exploitation of the connector's constraints, I would like to exchange with him on the forum, I have questions about the proposed values ...
Ignoring the Re exceedance. I try to make the manual calculation coincide with the constraints obtained by the solder connector...
I'm going to be a little curt and I apologize for that.
The only connector I don't use is this one.
Because it is misleading compared to the reality of your part in the workshop in post-welding. In addition, really look at the choices of the different types of welding (apart from the continuous bead)
I prefer the welding charts which better take into account the different types of welding. Not to mention that in real life there are differences between welders and even with the same welder, even if he is duly certified. It is only welding robots that make it possible to get closer to the PEF calculation.
I find it curious that the little crank pin hole is so blue when it is the one that will eat the maximum effort. I also notice that the tube is recessed in your crank pin (control lever). I don't see if the solder is on both sides. Normally the force should be on the axis of the small hole at the top of the control lever and the tube locking force should be on the rotating tube of the tangential tube. (we can't see what is blocking the rotating tube).
If I see correctly, you are doing a static study, but this type of assembly is subject to vibrations and shocks during start-stop. However, welds usually give way due to vibrations or peak forces during start-stop operations. (I recently had the example of a machine breakdown due to a poorly evaluated weld) It is also necessary to know the number of start-stop stops as well as the conditions of use (automatic with slowdown or manual action), especially in the event of a punch stop.
Regardless of your request, you would have to tell us a little more about the conditions of all your settings. Whether your parts are integral or not (e.g. without penetration) and therefore are really only held together by the welding and the contacts without penetration.
I say this because if you compare the F E M A with your manual calculation, it is unlikely that you will find the same results.
I think the easiest way would be to post your ASM with a "pack and go" so that we can really diagnose your simulation.
Kind regards
(PS: Cf. several discussions on soldering and soldering connectors)
Personally, using a surface modeling for a problem of this size is clearly heresy. The only interest of this simulation would possibly be to better understand the simulation results in terms of its management of the welds between hulls (but SW's help must already explain quite a bit how this is calculated and what the assumptions are).
I would have the same calculation to do, I will draw in volume (including the exact volume of the welds). In a solidary multibody or a merged unibody depending on what is sought.
But whether the result is a 30mm weld on a tube that is 88.9mm in outer diameter, clearly there is a big problem somewhere (conversion, units, value of Young's modulus...)
Hello Here is my simulation attached. I use the shells to have access to the solder connector, only I based my shells (3.5 mm) on 0.7x thickness of my ISO tube, the variation of the shells causes a repercussion on the strain stress but no influence on the weld apothem. With a coefficient of 3, and an imposed weld strength of 137 N/mm² I obtain a 30 mm bead. MAQUETTE M1.7z (4.1 MB) By reducing the safety factor from 3 to 1.25 and a breaking strength of S235 to 390N/mm² I have the apothema at about 5 mm. This becomes more realistic, and by calculation I find 6.35 mm which is close but not with a practical welding strength of 137.39 N/mm² to support a force of 55602 N. Here is my problem, I can't find my values...
The weld is on both sides, the idea was to decode and analyze the stresses recorded by the connector to then orient a design study from the values of the simulation. Concerning the use of the part and the conditions and cycles... Not all the information at this point, I can do breakthrough tests on prototypes to start. Thank you for your comments.
Spectrum.
P.S: I'm going to model the cord by scanning, that's the advice posted on the forum and I'd have the constraints by probes.
Don't forget to leave a space of 2/10 to 5/10 of a mm on the spokes and to declare that these two parts do not touch each other (formerly contact without penetration) so that only the contacts of the cords are reached. Otherwise, the crank pin tube contact must already be very resistant without welding.
Kind regards
PS: I'm going to ramble (yes yes!) You have to put the fixed parts and the effort correctly, which is not the case when I see the latest images posted.
Before to understand the connector I am on two pieces welded with two cords Here is my handwritten calculation note... I arrive at constraint values that I can't find in the connector. I have in initial data the imposed resistance of my weld at 140 N/mm², my external cantilever load of 12100 N with a lever arm of 150 mm; I determine my center of gravity relative to the first corner in direct opposition to the torque generated and I am very far from the SOLIDWORKS values. If a person is familiar with this connector I am interested in an improvement track otherwise I will move on to another simulator to understand by comparison. Thanks for the help.
the calculation of the Mr , M is the torque in N.m here my gross lever arm with my imposed force of 12100N (imposed by the quality of the weld). The r is the angle at the center of gravity of the two parallel weld seams. In dimensional equation, I have N.mm (the M) and r in mm.
Thank you for looking at my parameters, I'm stuck on the interpretation that deviates from my calculations... The constraints given for the cords, if I make an exploitation of his apothem, from the connector, as his is more important, I integrate although the constraint is weaker to oppose the initial force (the latter does not change, this is my initial data). Kind regards. TD N°2.7z (31.9 MB)
Good! Ouch! I am going to have to tell you again that this is not right! Sorry!
I think that before you want to do triple backward jumps in SW followed by a Tail grab followed by a back flip, you need to better understand how SW simulation works.
Meanwhile
If your goal is to test the equivalent of weld seams, you have to do it differently.
1°) As you have put the interactions between the components, it would be equivalent to having a single part that would be created in a single volume. As a result, you will never be able to see anything on the cords.
2° For the previous problem of the apothem, I suggested that you put a space between the two welded pieces, but I see that you do not take this suggestion into account. It may sound silly but it's the only way for the simulation not to glue the two decks together and consider it as a single volume.
Small problem I am in 2022 version so I cannot send you my results. As you are students and nice, I will make you a little video, you will have it in the afternoon.
For the comments between the simulation and the manual calculation I let @m.blt explain to you because he is a teacher and will be able to explain to you better.
In component interaction I chose free, is this my mistake? Thank you for the help, attached is a PDF of apothema search on a lifting ear for a tank, with screenshots of my cords. Kind regards.
Note that I don't answer your question which is to compare the results of the theoretical calculation and the calculation from the simulation (nice zozo!)
I was especially interested in showing what happens at the level of the cords because what is important is to understand the material. Incidentally, it is possible to use simulation with certain parameters and results.
With the help of your video, you give me the framework to follow to understand the installation of a weld bead in an assembly (or leave a functional game, I was in balance to use a virtual wall, but you don't use it, I can know the configuration of the link contacts:
first we remove the link given by the assembly (OK, NOK) -in second contact no penetration of the two parts (OK, NOK)
For volume cords, which option to use?
no penetration (OK, NOK) -solidarity (OK,NOK)
. I had discussed the search for bending on a pivotal link axis on the forum and the use of the separation line was the recommended tool to use.
I didn't know about design dissection , but here, it's very demonstrative about the extent of the constraints within a localized area, with a hidden base. Thank you for this visualization tool. No problem with my desire to cross the results by hand and the connector, I had used the connector only to have stress reactions, but with your volume approach I can probe the critical area and reassure myself about the hold mechanics. The calculation approach is to start from the surfaces of the sheared bead and not to exceed the weld stress, it is an imposed data that informs me of the length of the compatible beads. Your demonstration allows me to better perceive the behavior of the cord, it was my initial request, I am happy to have an additional tool in my box! Thank you In the case of combined loads, the spillage is instructive.
Some thoughts in the attached document, based on your model of mechanically welded plates. The idea was to compare the " solid cord approach" with the " connector " approach of the SolidWorks EF simulation module.
The conclusion in two words: a certain convergence of behaviours, with differences of around 10%. And the suspicion of a singularity in the volume approach, which makes the analysis of the results delicate.
As for comparing the results of these simulations to those of a " manual " (in fact theoretical) approach, I find it hard to imagine... In particular, what answer should be given to the question: how to evaluate the distribution of forces in weld seams, an essential prerequisite for an evaluation of stresses? Perhaps the Eurocode gives some information on this point, but I do not know enough about it.
I have just read your analysis and it directs me more towards the use of forces in the cords. Depending on the approach used, the convergence of results provides a good idea. Concerning Eurocode 3, I am not a specialist in this standard, however by applying it I find the values of the calculation notes. The parallel tau is validated (close value) on the other hand the sigma is never in the measurement range of my tests, so I will follow an analysis from the forces and it already suits me very well, thank you for the work done and the remarks/advice, attached a calculation note and a Eurocode 3 supplement (the cords), my base used. Kind regards.
1°) Solidworks and Simulation are two totally different applications. as a result, static simulation does not care about the constraints of SW CAD. It uses the pre-positioning of the parts between them and depending on your parameters will manage the contacts in one way or another.
By the way, you will notice that the first action it takes is the management of contacts, it will analyze all the contacts (at nodes) between each room.
Depending on the criteria and simulation parameters, it will or will not allow interpenetration between the parts "for example, the old function without penetration made it possible to have a gap between two parts of several millimeters. If, under the effect of the forces imposed, these pieces ended up coming together, then touching each other without being able to interpenetrate. I have seen too often in the version below 2021 people focus on the 'No penetration without having understood what I have just explained about the management of global contacts.
So answer to questions 1 and 3 = KO For question 2, the cord in the case of your assembly is considered a triangular piece in contact with the two plates. If you have set at least two constraints, you don't have to worry about them. It is the management of contacts at the nodes that will manage.
On the other hand, a little advice, if one day you make mechanically welded frames with parts other than welded profiles, check that all the parts are with constraints (therefore with contact).
I have the 2022 version, see if you can have the 2022 student version, it will be simpler if you have other questions afterwards.
Thank you for your informative document on several points. I have read your document carefully except that I do not find the same values as you (strange). Could post your ASM in pack and go so that I can compare our two versions and settings.
How do you manage to have the two representations on page 3 (I don't know).
I put forward a hypothesis for the difference with the connector! When there is welding (i.e. fusion of metal between the two parts plus the material of the weld, Simu no longer considers as knot-to-knot contacts between 2 parts, but as if the three parts were made in a single body (a single PRT). We could make a single piece to see if the hypothesis has any value.
A first possible explanation for the differences in values between our respective models: I reduced the external load to 2000 N. Also a collection of details in the model parameterization that can induce differences.
As for the gap between the volume model and the connector model, it does not shock me insofar as the models are different. The SolidWorks simulation module is sometimes sparse with details on the principles used.
For the illustrations on page 3, there is nothing very mysterious:
The first is a von Mises constraint plot, by checking the " Show plot only on selected features" checkbox in the " Advanced Options" area, and then selecting the faces to use for the representation.
the second is a display of the values of forces exerted at the level of a surface: " Results " options, " List of resulting forces". Select the faces or edges to be examined, then click the " Update " button. Depending on the origin of the force (external load, force between components, etc.), you must tick the right box in the " Options " area. Moments are also offered if a torsor reduction point is selected.
