Shear web with unstiffened holes
Shear web with unstiffened holes
(OP)
Hi all.
Can anyone suggest a design guideline for a shear panel that has holes without stiffening? I am actually evaluating a shear plate with certain cracks, and I figure that replacing cracks with holes for one time proof loads is a decent approximation for the order of magnitude of capacity lost due to cracking. This is for resisting buff loads on a passenger railcar.
Thanks!
Can anyone suggest a design guideline for a shear panel that has holes without stiffening? I am actually evaluating a shear plate with certain cracks, and I figure that replacing cracks with holes for one time proof loads is a decent approximation for the order of magnitude of capacity lost due to cracking. This is for resisting buff loads on a passenger railcar.
Thanks!






RE: Shear web with unstiffened holes
and buffet loads implies out of plane loading ?
RE: Shear web with unstiffened holes
RE: Shear web with unstiffened holes
I certainly can provide fea of various cracked arrangements, but it's not clear to me what allowables I could use given buckling.
I'm not a big fan of FE eigenvalue buckling analyses because it's been shown they tend to overestimate buckling loads.
Any suggestions would be appreciated.
Tg
RE: Shear web with unstiffened holes
I’d look at these shear plates like buckled webs on a plate girder. They first start acting in shear, then buckle out of plane, and then start acting as a tension field of some depth, from the stub sill web to the side sill. And, I would certainly use FEA to study this problem, just not expect exact (certain, absolute) answers from it. I’d do the FEA model to represent the as built end frame, on two supports at the side sills, and loaded at the rear draft lugs, and run that through the normal draft and buff loads, and the 800k impact load. Then introduce the cracks one at a time (a linear discontinuity 1" long, for example), and only one at a time, to see what these did to the stress picture After the impact a slightly crumpled car end outboard of the body bolster is o.k. as long as the rest of the car is intact. Are these transit cars or over the road passenger cars, how old? I don’t think there is an exact answer to your problem, the next crack will be slightly different, starting at a slightly different defect. All you can do is offer some good engineering judgement about a range of failure loads and the nature of the failure. You might see that some cracks and the details that caused them should be welded up and cleaned up, while others are of little consequence, but I’d still drill the tips. I’d like to see an end arrangement drawing and some details.