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Rivet Design
- Thread starter ToadJones
- Start date
- Thread starter
- #22
I see old texts that list the allowable shear and allowable bearing values for rivets.
Unless I'm over thinking this, its not making sense to me.
check rivet shear, bearing at the rivet hole. Should I be checking bearing on the rivet itself?>
Unless I'm over thinking this, its not making sense to me.
check rivet shear, bearing at the rivet hole. Should I be checking bearing on the rivet itself?>
paddingtongreen
Structural
I have to confess to designing a few riveted joints, The rivet is assumed to, and usually did, fill the hole so it is correct to check the hole size. It really doesn't matter, if the rivet size was checked, then slightly higher stresses would have been allowed. Intuitively, it might have been better to use the rivet size.
The best thing about rivets, for me, was drawing the girders, I worked with a designer who was assigned to the "Cat Cracker" structure for Fawley Refinery, I had just enough drawing experience that he let me do the drawing. The vessels weighed in the region of a thousand tons so the structure was massive.
I found a picture of the actual unit that I worked on:
Michael.
Timing has a lot to do with the outcome of a rain dance.
The best thing about rivets, for me, was drawing the girders, I worked with a designer who was assigned to the "Cat Cracker" structure for Fawley Refinery, I had just enough drawing experience that he let me do the drawing. The vessels weighed in the region of a thousand tons so the structure was massive.
I found a picture of the actual unit that I worked on:
Michael.
Timing has a lot to do with the outcome of a rain dance.
We get so soon old, and so late smart, was what my Father always said. But, BA has it all, a quick 39 year old mind and about 70 years of experience. I‘m guessing that’s total years BA, not years of engineering, because you started computer programming a few years before I did. It’s a shame we can’t bottle it and sell it, right BA?
My take on soft pins, rivets or bolts; without the benefit of Toad’s “allowable shear and allowable bearing values for rivets” is that given a dia. and a matching steel grade, the shear stress at yield or ultimate is generally enough lower than the bearing stress at ultimate, that the shear stress usually governed the design. I considered bolt bearing in some joints because, given fit-up and over sized holes, I knew that some bolts would be causing considerable yielding in bearing on the hole edges (and thus high shears at those bolts) before all the bolts were brought into play, thus joint slip. This was not a perfectly rigid joint it had to move some before it became fully effective. And, this same thinking is likely what causes some of the cracking you see in your crane rail girder webs. Despite the fact that you didn’t read that into one of my earlier posts. That’s very high localized stresses and fairly low cycle fatigue or fracture problem. This same thinking is why bolts and welds in a joint are not additive for a total joint capacity, the bolted joint must move and the weld is rigid and takes all the load. If we cared, and particularly on plate girders, we decreased the hole oversize and match drilled the holes on splice plates and webs or flanges. This minimized the joint movement and gave us more confidence that most of the bolts were acting. Since rivets filled the holes they tended to act in proportion to their number too.
My take on soft pins, rivets or bolts; without the benefit of Toad’s “allowable shear and allowable bearing values for rivets” is that given a dia. and a matching steel grade, the shear stress at yield or ultimate is generally enough lower than the bearing stress at ultimate, that the shear stress usually governed the design. I considered bolt bearing in some joints because, given fit-up and over sized holes, I knew that some bolts would be causing considerable yielding in bearing on the hole edges (and thus high shears at those bolts) before all the bolts were brought into play, thus joint slip. This was not a perfectly rigid joint it had to move some before it became fully effective. And, this same thinking is likely what causes some of the cracking you see in your crane rail girder webs. Despite the fact that you didn’t read that into one of my earlier posts. That’s very high localized stresses and fairly low cycle fatigue or fracture problem. This same thinking is why bolts and welds in a joint are not additive for a total joint capacity, the bolted joint must move and the weld is rigid and takes all the load. If we cared, and particularly on plate girders, we decreased the hole oversize and match drilled the holes on splice plates and webs or flanges. This minimized the joint movement and gave us more confidence that most of the bolts were acting. Since rivets filled the holes they tended to act in proportion to their number too.
- Thread starter
- #27
ha! ha!- Thread starter
- #29
jheidt2543
Civil/Environmental
Toad:
You didn't mention the author of the book the page is from, could you??
You didn't mention the author of the book the page is from, could you??
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- #31
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