Splicing Stainless Steel

[JNEnginr]

Hey Everyone,

Seemingly simple situation. I have two 1/2" thick by 5" wide by 15ft long stainless steel members. I need to splice them together and load the whole member in bending (strong axis), and wanted to know if it was possible to do so with a 1/2" splice plate simply by screwing screws in a row into the splice plate, and half the total screws into each 15 ft member. (i.e. 8 screws total, 4 into each member) The constraints are that the screws cannot penetrate completely through both members, just through the splice plate and into the 1/2" thick member. Due to the loading of the member, there is a 2 kip-ft moment at the location of the splice. And welding is not permissible due to the finish of the stainless steel.

Now I know AISC has no say on the connection of structural members using machine screws. Is there any code/design guide that addresses the use of machine screws?

 

[fegenbush]

Machinery's Handbook is the reference I use for machine screws.

 

[ztengguy]

Handbook of bolts and bolted joints might have something too about it.

Are you worried about deflection? I would think the plate would need to have some tolerances, unless you thread it all at once, and if not, the screws would need to be pretty tight for it not to deflect. Also self weight deflection on a 5" tall member might be alot. Is your span going to be 30' when done?

 

[JNEnginr]

Actually, the member is vertical, so self weight isnt an issue. And yes, deflection is a concern, but my bigger issue is justifying the development of the moment out of the member, through the screws, into the splice plate, and then back into the screws and into the next member.

 

[shobroco]

You're just looking at shear in the screws, if you can analyze what that is through the splice. Resolve the moment into forces across the screws & size them to carry it.

 

[MikeHalloran]

Before you get too deeply involved in designing a splice, call your steel suppliers and see if you can get 1/2 x 5 flats in 30 foot lengths.

You never know what's available until you ask.




Mike Halloran
Pembroke Pines, FL, USA

 

[JNEnginr]

Shobroco: My intent is to do just that. My question lies in the sizing of the screws themselves and their corresponding shear capacities. Is it simply a matter of taking the shear capacity of the screws? Are there any other failure mechanisms that need to be addressed? And is there a governing code/design guide that these connections should conform to?

I know I may be overthinking this, but I'm just looking for something like the aisc manual design for connections, telling me criteria to be met and checks to perform. Is there such a manual?

Thanks again for all the feedback.