Bolted and Welded Joints

[luzerne22]

I'm studying for my professional engineering exam and came across a problem that was never really covered in my courses in school. I was wondering if I could get some input from some people.

Design a bolted joint to attach a suitable american standard steel channel at an 18 degree angle to store a bundle (16) of 8x8x1/2 x 26 feet long square structural tubing. An identical member 16 feet away supports the other end of the bundle which can vary off center by two feet. The W18X55 vertical members and the channels are made from ASTM A242 steel,. Specify the number of bolts, pattern, material grade, diameter, length, and maximum torque.

Additionally, the same problem except a welded joint instead of a bolted joint. Specify the minimum weld pattern, the type of electrode to be used, and the size of the weld.

Thanks for any help!

 

[GregLocock]

And what do you have so far, and which school was this?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[luzerne22]

I have the weight of the 16 lengths of tubing. Which is roughly 20,500 pounds. The weight of the channel of course will be dependent on the length I chose to design with. Where I'm stuck is the Moment. I feel as if the problem is missing information regarding the distance the beams are from the support. Unless that distance can be chosen or assumed, just a bit of a road block right now. And the University of Toledo. I checked my mechanical design book, it was the last chapter that we never got to and the chapter very roughly goes over the design of bolted and welded joints.

 

[dvd]

One way to tackle this would be to block out one flange of the beam and bolt the web of the channel to the web of the column. The problem seems ambiguous for a PE exam question.

 

[luzerne22]

I thought the same thing.. but its in a big packet that was given to me at the advising office of the school. Using that approach, the R value is the part that I'm struggling to determine

 

[dvd]

How close can the centroid of the bundle get to the column? Draw a picture.

 

[luzerne22]

the picture that is given is the 16 lengths of tubing in a 4 x 4 bundle. The top left corner of the bundle is shown against the column. So with the 18 degree angle I guess I can do some trig to figure out the centroid of the 32" x 32" square. Then use the resulting forces to find the moment about the center of the bolt pattern? equally divide the load on each bolt, determine diameter, stress for material? Do you feel as if I'm headed in the right direction?

 

[rb1957]

you're designing a rack to hold the 16 pieces of sq. tubing, right? you're designing one end of the rack (and the other is 16' away). since the tubing is 26' long, there is some variability in the load reacted by the two supports (so you can make a story for the conservative load on your support; wait, they tell you how to account for this).

you're right ... how wide to make it ? (ie the distance between the columns) ... well, how wide do you want to make it ? certainly there's a minimum ... and you might think how easy? it might be to stack 4" tubes 8 high if it was easy to the top tube to roll off ??

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