FG - Custom Notches/Cut-Outs, Simple Connections & Back Marking

[Anonymous]

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FG currently creates Notches that are virtually impossible for a fabrication shop to produce economically.

In the UK there are de-facto standards, that fabricators all know, which means there's less chance of errors (p B-42 [yellow] of the attached Blue Book gives an example).

Further examples of Simple Connections and their related notch are given by Steel Construction Info

https://www.steelconstruction.info/Simple_connections

The bolts holes are determined by Back Marking, more info can be found here

http://www.roymech.co.uk/Useful_Tables/Sections/Bolt_Holes.html

I'm not suggesting these are the same everywhere around the world, which is why these need to be customisable for individual situations and circumstances etc.

[PaulMunford]

Hi @Anonymous,

Does this help?

http://autodesk.blogs.com/between_the_lines/2018/07/inventor-tip-frame-generator-custom-notch.html

[Anonymous]

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@PaulMunfordthat would do the trick

Begs a question, why was this option included, but never utilised by Autodesk ?

The Notches I mentioned are a combination of existing parameters rounded-up to the nearest MM.

Next, we just need "Back Marked" bolt holes that "pick up" dims/parameters from the selected FG/CC-beam etc.

[martin.pelak]

 Hi @Anonymous

   We are currently considering some improvements for frame generator and I would like to understand better how you design notch profiles. Could you please help me answer these questions?

1. Have you managed to create notch profiles for your frames?
2. What kind of profiles (U, L, I, ...) do you need to create notch profiles for?
3. Which parameters from the blue book do you use? Which are less important and which can be neglected?
4. Do you need multiple notch profiles per frame?
5. How would you proceed if size of a frame cannot be found in the blue book? Does it ever happen?  

  It would be great if you could share with us an assembly or content center library with frames which have custom profiles.

Thank you, Martin.

[Anonymous]

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@martin.pelakthanks for such a detailed response. I'll interleave my answers.

Have you managed to create notch profiles for your frames?

So far I haven't. Only found out about custom notch sketch the other week and am too busy at present.

What kind of profiles (U, L, I, ...) do you need to create notch profiles for?

I'm a Mechanical Design Engineer, not a Structural Design Engineer. I try to avoid structural steel work, but sometimes the things we design need to go on frames. Consequently, I tend to keep the joints between frame members simple. Furthermore, it is easier for the fabricators if we use consistent types of simple joints and as there are de-facto standards (p 108/708 {B-42} of Blue Book for example} and  The Green Books I would tend to use these. When connecting via a "fin plate" or to the web of another member . It also depends on whether the connection is bolted or welded. Welded needs to be fairly close, whereas bolted connections need more room. I think this might be something for iLogic, is the connection welded or bolted. Fortunately, both are related to existing parameters/dimensions of the relevant section - possibly +10mm - and then rounded-up to nearest MM. This means one sketch could cover all welded and another sketch could cover simple bolted. If these parameters were accessible through iProperties it might make it easier for somebody to switch between bolted and welded.

Which parameters from the blue book do you use? Which are less important and which can be neglected?

All of them are used one way or another. They are all calculated from the section profile and the orientation of the beam element. These parameters are given to save Designers from calculating them each time. Each one can be calculated from the parameters/dimensions and if made accessible or exportable from iProperties they could be used in other applications to produce the documentation needed for C.E Marking. Unfortunately, I can find out where at present, I'll keep looking. I can look at the list of parameters that I would likely use and unlikely use, it would be unlikely that I would use Surface Area as this would be related to effect of temperature changes, possible fires. You might want to undertake a larger survey - possibly Survey Monkey or similar.

Do you need multiple notch profiles per frame [element]?

The only difference I can see is between welded and Simply Bolted, you can include Moment Resisting but I'm unlikely to use it. The sketches could be easily driven from existing section parameters and rounded-up. Or in the case of Simply Bolted a nominal amount is added, I think 10mm for clearance and for steel workers to get the beam into place when fitting on site.

How would you proceed if size of a frame cannot be found in the blue book? Does it ever happen?

For stuff  I'm designing I would only use steel sections that could be purchased easily, namely stuff that's in Blue Book. The only time I've had this problem is when reverse engineering an existing structure so we can fit the new to the existing. Firstly I look elsewhere in FG/CC, if that doesn't work I customise the FG element in-situ - there is a way to get to the sketch and parameters, can remember at present. We wouldn't do that for new, just the existing so we had something to work too and we would cross check it with 3D Scan.

Hope this helps

[martin.pelak]

@Anonymous Thank you very much. Your post has helped a lot.

I found some formulas in the Blue Book (Steel Building Design: Design Data, published by The Steel Construction Institute and The British Constructional Steelwork Association Limited)

2.3.1 UB sections, UC sections and bearing piles

N = (b - tw) / 2 + 10 mm (rounded to the nearest 2 mm above)

n = (h - d) / 2 (rounded to the nearest 2 mm above)

C = tw / 2 + 2 mm  (rounded to the nearest mm)

2.3.2 Joists

N = (b - tw) / 2 + 6 mm (rounded to the nearest 2 mm above)

n = (h - d) / 2 (rounded to the nearest 2 mm above)

C = tw / 2 + 2 mm  (rounded to the nearest mm)

Note: Flanges of BS 4-1 joists have an 8° taper.

2.3.3 Parallel flange channels

N = (b - tw) + 6 mm (rounded up to the nearest 2 mm above)

n = (h - d) / 2 (taken to the next higher multiple of 2 mm)

C = tw + 2 mm  (rounded to the nearest mm)

[Anonymous]

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3.1 refers to Section 1.1, which refers to BS EN 10025.

This gives the Mechanical properties of different grades of steel, for example; S235, S275 & S355.

I'm in the process of compiling a new Invertor material library for the steel mentioned in EN 10025.

I was hoping you could help me.

Under American Standards are; Young's Modulus, Poisson's Ratio & Shear Modulus used for calculating the mechanical strength of the structure/component ?

Are they (Young's Modulus, Poisson's Ratio & Shear Modulus) used by the F.E.A environment in Inventor ?

As we don't tend to use them it isn't easy finding this information in relation to Structural (S) and Engineering (E) steels.

[Pavel_Holecek]

Hello @Anonymous,

Yes, we use these material properties for FEA.  If you do not have  all important material properties FEA will let you know that.

in case you do not have a material with these properties you can use another material from combo box which is relevant to your. It is enough to check 'Customize' and expand combo box with list of materials.

regards

[Anonymous]

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@Pavel_Holecek& @martin.pelak as Europe is now working to EuroCodes, most notably EC3 I have found the definitive answer from EuroCode 3 EN 1993.1. {p28}

Can't argue with that.

[martin.pelak]

@Anonymous I am glad you found it. A colleague of mine recommends this website http://www.matweb.com/

[Anonymous]

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@martin.pelak for more information about the gap for welded fins look at Chapter 5 of SCI P358

[Anonymous]

I've been an Inventor user for 17 years & have been modelling steel structures & architectural metalwork for the same amount of time for customers all over the UK, I use the FG every day, week, month for every project.

The notch command in FG has been totally unpractical since the beginning, but this is a solution & its been there all these years, but Autodesk didn't know it was there & what was more annoying the solution was simple.

But before I go on more, the new notch command isn't the solution neither, so Autodesk, stop it now, your wasting development time & still not providing the user with the ability to control variations in notches.

I found a solution to create notches in PFC, UB, UC & with square cuts, radiused cuts & any variation the user needs & I do it every day in my job & it works fine & I don't have any programming knowledge at all.

So, if I can do it, so can everyone else, only if Autodesk would listen, but I don't need a notch command, because I have one & it can be changed at any time when modelling to suit a non-standard situation.

I have explained to Autodesk how to do it & what's required for the benefit of the user.

[Anonymous]

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@Anonymouswrote:

I found a solution to create notches in PFC, UB, UC & with square cuts, radiused cuts & any variation the user needs & I do it every day in my job & it works fine & I don't have any programming knowledge at all.

So, if I can do it, so can everyone else, only if Autodesk would listen, but I don't need a notch command, because I have one & it can be changed at any time when modelling to suit a non-standard situation.

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Gary,

I'm curious about how you create notches etc.

Have you posted any examples to Adesk's public forums ?

TIA

[Anonymous]

Duncan,

The solution to custom notch is already there, the problem is, that Autodesk & the resellers haven't shown the user how to use it.

[martin.zatecka]

Hello,

At the moment you can author one own notch profile directly to your template. I apologise the missing details in help, you can use this link https://youtu.be/L8QRbBCxlXA to watch a short video tutorial.

Regards

Martin