how many rivets should i choose?

[jealous-fish]

hello guys,
I'm finishing the assembly of two parts,I did the design and everything but I'm stuck in choosing the correct number of rivets to use.As you can see in the image I have chosen a profile between the two parts for assembly and I already decided for riveting.The two parts are sheet metals with both thickness 0.6 mm there is no significant load that they should support they only should support their own weight, which is not that big (given their material), I already did all the calculation necessary for choosing the type of the rivets, but all of the references I saw said that the maximum distance between two holes of rivets should be 10*d, with d the diameter of the Hole, but this gives me about 65 rivets which I think is a lot.I know that I can choose a number of rivets and it mightbe enough, but I'm looking for a justified answer that I can give in my presentation.
I would really appreciate any help
thank you

 

[IRstuff]

The rule you found is for the smallest distance possible for rivets to be, before the material yields because there isn't enough material between the rivets. What you need is something that tells you the holding strength of a single rivet and then go from there

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[drawoh]

jealous-fish,

Are you optimising this thing for strength, or for cost? Fewer rivets is cheaper [—] fewer holes, fewer rivets, fewer install procedures, etc. How many rivets are strong enough?

--
JHG

 

[BAretired]

Part 2 appears to be a shelf. We don't know the weight of the stuff you intend to put on the shelf, and we don't know the width of the shelf, but the applied load is eccentric to the vertical plate, so it will cause a moment.

The strength of the connection depends on the tensile capacity of each rivet and the flexural capacity of the attachment plates, which appear from your sketch, to be considerably thinner than the 0.6mm plate.

It is not clear how the attachment plates are to be fastened to the vertical plates. Why did you opt to make two parts? It would have been much better to combine Part 1 and Part 2 into a single piece; then you wouldn't need any rivets.

BA

 

[jealous-fish]

I know that I didn't include a lot of information about the assembly. The two parts represent two sheetmetal for the exterior of refrigerated Display unit I know that this might seem like a noob question, but I really could not find a justified answer, like I said I found in The references that the maximum distance between two rivets in my case is 31 mm which will give me about 65 rivets And I'm afraid of the ' why did you choose that many rivets'. There is no load applied on the two parts they only need to be assembled, simple assembly. I already did a design of a structure that holds the shelf and the outer layer of the unit including the two parts in the pictures. I really appreciate any help guys.
Thank you

 

[jealous-fish]

part 2 is in contact with ground and it weights 17 kg, part 1 weights 8.5 kg

 

[jealous-fish]

drawoh
i'm optimising it for cost

 

[BAretired]

That is an entirely different story. Does that mean Part 2 acts as the base of a standing display? If so, what is the weight and location of the displayed material? Is Part 2 adequate to prevent the contraption from falling over? Also, can you come up with a simpler way of attaching Part 1 to Part 2 other than two "Z" shaped connectors?

BA

 

[jealous-fish]

BAretired
yes part two acts as the base but like i said there is a structure that holds everything the shelfs and the exterior of the unity including the two parts in the picture. there is no load on the two parts just their own weight.

 

[BAretired]

I take it that the unit is approximately 2000mm long (31*65 = 2015). If the top of Part 1 is laterally braced to prevent it from falling over, the rivets are essentially just keeping the two parts in line where they meet. In that case, a spacing of 100mm seems reasonable. If part 1 is not laterally supported, the whole thing is likely to fall over with a whiff of wind or nudge by a passerby.

I still don't know how you propose to attach the "Z" shaped pieces to the vertical walls of Parts 1 and 2. Have you considered overlapping Parts 1 and 2, then riveting through both walls?

BA

 

[jealous-fish]

yes there is a lateral support , i could not upload the step files since the assembly is too big ( app 400 Mo ) and also there are some parts that i did'nt finish yet , but i i will upload the whole thing when i'm done . its a whole project with a big part of it calculating the power of condensing unit and the evaporator . there is also a numerical simulation to verify if the structure that i choose will hold.

 

[jealous-fish]

how can i explaind that 100 mm is enough?

 

[BAretired]

there is also a numerical simulation to verify if the structure that i choose will hold.

Really? Why don't you show us?

how can i explaind that 100 mm is enough?

Explain to whom? And why does it have to be explained? If Part 1 is attached to a structure, Part 2 is not required, or if required for aesthetic reasons, does not have to be connected to Part 1.

BA