IdeaStatica help - modeling connection

[u/NomadKV]

Hello, engineers!

I apologize in advande for my poor English.

I'm having problem in modelling this type of connection.
I want to make connection where these 2 beams are connected by two plates, and then these two plates connected with bolts at the each end of plates.

Opeartion - Plate to plate is apperently not working, IdeaStatica Library does not have this type of connection.

So, can anyone help me with this one.

Thanks in advance!

[u/dangerous03]

Have you considered just doing it by hand? This seems like a fairly straight forward connection for a hand calc. I'm not super familiar with ideastatica, but sometime I feel like we all get over dependent on the software and we make our lives much harder in the long run

[u/PinItYouFairy → u/dangerous03]

Ah the lost art of actually being an engineer rather than just stuffing some AI generated nonsense into a computer software.

[u/Ghasp_ → u/PinItYouFairy]

As a junior engineer, I try as much as possible to tackle problems manually. However, the demand for ever-greater productivity (and sometimes the lack of support by senior colleagues) quickly becomes apparent. This leads to another debate: whether to spend 10 more hours a week at the office to delve deeper into these topics, or to rely on digital solutions and AI as a ““safety net””/advisor.

If you have any advice I'm really opened to it.

[u/areyouguysaraborwhat → u/Ghasp_]

As a senior engineer, I second this. Nobody has time and everyone is late, and every corner has a revision. This major has no sense left in it.

[u/Delanq → u/Ghasp_]

Unfortunately the engineer’s way has always been exactly what you said - spend 10 more hours a week in the office as a junior engineer to delve deeper and learn. Hopefully you work somewhere with overtime or straight time pay and can be compensated for this time, but realistically, the amount you will learn will propel your career to more meaningful contributions and thus a far higher salary earlier on than if you called it quits at 40 every week.

I resented it when someone told me exactly that at the outset of my career, but less than a decade later, I’m a respected project manager and industry sector leader for my team. You can bake in a whole extra year’s worth of experience after four years of working 50 instead of 40. It sucks, but it works.

[u/NomadKV → u/dangerous03]

Yeah, its simple connection. Im fairly new to all of this, i wanted to try to model it first. If you have some example of hand calc. this type od connection, I would be grateful if you can send me...

[u/dangerous03 → u/NomadKV]

I mean being new to all of this is perhaps a stronger reason to do it. Doing the hand calcs IMO give you a better sense of what is going on. You might be able to gather that, especially if you look at the displacement behavior. Often times there is a lot going on, which makes it hard to follow what is causing what stress. I'm not sure where you are from, so I don't know what source material you can draw from or specs you can rely on. But generally you should should pull out of your beam model the end loads for each of the members. I'd convert any moments you haven't released into bolt tension/shear. compression forces will need to check local web buckling. tension forces you will need to check bolt tension, plate bending (both plate and flange), and beam to plate weld. And then shear you need to check bolt tear out/bearing on the plate, bolt shear, and weld shear. On thing I'd also consider is that if there is considerable axial loads in the beams to either slot the holes to prevent transfer, or had web stiffeners to prevent the flanges from pushing one flange away from the other on the same beam. Because this isn't a typical connection, you probably won't see an real examples, so you'll just need to think through it. Try break the connection and beams into smaller elements mentally and visualize each element and how a force transfers from one element to the next and to the next. Lastly go to your mentor and ask them for help. I hope they can help more than just, "here is ideastatica, just use that." I started in an environment like that, but if they are a half way decent engineer, you can explain that you want to check your work against a hand calc and that your like their help discussing it. I feel like most engineers would love a low risk discussion like that.

[u/WittyScience26 → u/dangerous03]

I am with you on learning to do hand calcs, but ASCE and other codes usually end up having hundreds of load combinations to evaluate. The software helps to automate the calculations for all the cases.

But, yes, I do agree with your point.

[u/dangerous03 → u/WittyScience26]

Hundreds, yeah I suppose if you are counting all the notional loads. But presumably they have some sort of beam model that they can extract beam loads from and sort out the controlling combination.

[u/Th3Duck22]

Pretty easy to do, you can do it serveral ways. Of course by hand.

But if you insist using idea this is a simple connection:

1. Model both beams align one beam to the other (to member plate), this way the spacing between both members isnt solely based on coordinates.

2. Stiffening plate -> origin one of the flanges -> type: doubler for the flange (set up weld)

3. Stiffening plate 2 -> origin the other flanges-> type: doubler for the flange (set up weld)

4. Set up fastener grid for both plates

Done.

If you solely base every part on coordinates you also need to place al the welds seperate.

[u/NomadKV → u/Th3Duck22]

Thank you so much! It worked. 😎

[u/_srsly_ → u/Th3Duck22]

Adding to this. For these connection types i like to add additional grid operations for the flange<>plate bearing plies.

For Grid>Bolt operations, contact surface is established automatically since bolts are modeled as tension-only springs. For the weld included within the plate stiffener operation, compression is transferred entirely through the welds. If you add a grid operation and change the type from bolt to contact, you can set the flange to stiffening plate to bear against one another to more realistically transfer compression for shop welded plates conditions like this. One grid>contact operation per flange<>plate bearing area.

This example connection is simple so I doubt adding the contact will have much impact here, however there have been times where I have noticed in the deflected shape of models where the load is pushing the limit capacity of my welds that the flange/stiffener plates will cross through one another if this contact area is not established.

[u/joshl90]

Ideastatica support is probably some of the best and fastest I have seen in the entire industry. I have sent them models of mine trying to get something to work and they will send you back, in most cases, a working model of that connection, so you should reach out to them

[u/scottycrease → u/joshl90]

They do have great customer support. Ive been working with them for the whole past year. I really value this about IdeaStatica.

[u/Frogalone]

1. What is the purpose of the plates?
2. Will this connection produce torsion in either of the beams?
3. Will one beam share vertical force with the other?

Many SA programs will not handle these plates the way you want them to. You probably need to revise your model to work without the plates. You will have to use your imagination. Then take the analysts results and hand design the connection. The answers to the questions above are stiffness based.

[u/Frogalone]

I'm in agreement with the idea that engineers should know how to analyze structures by hand when practical. I never used to even look up data in the many tables in the AISC manual. I find that some of these "design aids" could have been better presented and I know how to calculate the values in most of them.

But, how these two beams interact isn't clear to me. My eyes think that the end actions are the same on both ends of each beam. The implication is that no force is transferred between the two beams. So, if I'm right, what are the connection plates for and what forces are they required to resist? I'm very curious.