Cat Excavator Bucket impact

[trainguy]

Hi all.

We are trying to size a steel member that will receive impacts from a Caterpillar excavator bucket's bottom edge (with teeth!). Think of this as a steel pad welded to a flat steel floor. Can anyone suggest a design load for the pad to floor connection if the bucket is expected to impact this? We are not sure where to look.

Bucket weight?
Portion of boom weight?
Deceleration in g's?

Other sources of info?

tg

 

[WARose]

I'm not 100% sure I follow the situation......are you saying you are trying to design for a "impact" as in the bucket slamming (horizontally) into a member attached to the floor?

 

[Deadblow]

Can you tell us what model excavator? What size bucket? Will the operator be hitting the steel as hard as he/she can or will he/she just be scraping it? What is the purpose? What will be considered a "failure"? A quick sketch would go a long way here!

EIT

 

[cvg]

cat performance handbook
chapter 7 Hydraulic Excavators

http://www.albancat.com/content/uploads/2017/08/SEBD0351_ED47.pdf

 

[dhengr]

Trainguy:
You are talking about a backhoe type excavator, and not a rubber tired or tracked front end loader, right? The questions above still need answers too. For the most part, it is not a dropping weight type impact, as all of these buckets are driven down hydraulically, not too fast, but not free falling. But, the hydraulics are strong enough to actually lift the front of the machines, so the potential vert. load is about half the weight of the machine, with some impact. They are also strong enough horiz., in bucket/boom movement, to almost push/pull the machine laterally. If the bucket hits the stl. fl. with the flat bottom of the bucket, the loads are fairly nicely distributed. But, if they tip the bucket so the teeth can hit the stl. fl. then you really have a punching/ripping action on the fl. pl. The actual weight/load is something of a judgement call, as the operator could go out of his way to try to drive the bucket down. I would talk with a typical machine supplier for their guidance on possible loads from a given machine. I would space the wear/reinf’g. plates at less than a bucket width, and have their width be a couple teeth spaces wide, so several teeth hit the wear pl. at any one time. If this is the stl. fl. of a railcar, I would pay some attention to the crosstie and cross bearer spacing, but you probably can’t prevent some fl. pl. bending without the wear pl. getting so thick you can’t clean the railcar out. You just don’t want the bucket teeth scrapping or piercing the stl. fl. pl. You might want a heavy angle iron protecting the side to fl. corners also.

 

[oldestguy]

Make a full depth weld and be done with it.