Signs of mechanical wear/damage and their origin 1

[Walterke]

Does anyone know of some kind of website/book that lists different kinds of possible wear/damage on metal and their origin? We received pictures from a customer (which I am not at liberty to share) with a kind of damage I can not seem to place.

I apologize for the vague description.

NX 7.5.5.4 with Teamcenter 8 on win7 64
Intel Xeon @3.2GHz
8GB RAM
Nvidia Quadro 2000

 

[chicopee]

You should be a little more specific as to what was worn out or damaged.

 

[kingnero]

visit your local tribology research center at university, they'll have plenty books about this subject.

 

[DRWeig]

Yes, please do what chicopee asked. You can be generic so as not to identify the company.

Just in case your problem is with bearings, attached are a couple of good references.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[DRWeig]

Here's the other one:

Best to you,

Goober Dave

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[Walterke]

The damage situates in telehandler booms. We see straight lines on the boom, almost like someone carved them in.
Weird thing is that most of them are in the bottom part (=pressure part, not tension part) of the boom.
Lines run in a plane perpendicular to the length of the boom.

Not allowed to post pictures, sorry.

NX 7.5.5.4 with Teamcenter 8 on win7 64
Intel Xeon @3.2GHz
8GB RAM
Nvidia Quadro 2000

 

[MintJulep]

You might find something useful here:

http://www.asminternational.org/portal/site/

http://www/store/storeList2/?category=,T02,&categoryName=Failure Analysis

 

[dhengr]

Walterke:
Imagine the concept of giving enough info. so that there could be a meaningful discussion about an engineering problem. Then imagine sharing some photos which probably don’t identify the equipment designer or builder, but might show something that an experienced engineer might have seem before and recognize, and be able to comment on. Then, imagine not doing any of that dumb stuffr and being silly enough to think you will get some meaningful comments from people who can’t see it from here. You have just created/posted the perfect thread. I would just go to www. answers/is/us. They have millions of answers for everything. You pick the answer that best covers your a.. And, they don’t confuse the issue with a need for any meaningful question, with enough info. to start a serious discussion.

Something is rubbing or grinding at a bearing point or an inadvertent touching point, within the boom, at any boom extension length where it remains while some lateral action out at the boom tip can cause lateral motion back in the back span of the boom.

 

[Artisi]

Alternately, visit the local fair when it comes to town and go see the fortune teller - results guaranteed for the appropriate fee.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[bigTomHanks]

http://www.sciencedirect.com/science/article/pii/S0924013609002829

Shot in the dark.

Without any information it sounds like it could be a result of the manufacturing of the tube extrusion.

 

[tomwalz]

+1 for bigTomHanks

Any idea how the part was made. If extruded, any post treatment? I am thinking maybe extruded just a little cold. If post treated maybe a short cycle and not treated all the way through.

dhengr and Artisi make good points. However, in my world, it is not at all unusual it get a call that goes something like "I have a part here that is maybe steel and it broke. Can you tell me why and how to fix it?" We start from there and eventually figure something out.

My problem solving method sometimes works like yours. Quite often someone will pipe out and say "I'll bet that is an Acme 423 boom from 1998. They got bad steel for those."

Good Luck,
Tom

P.S. I don't suppose you or anybody previously is doing anything strange with that equipment?



Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[chicopee]

Telehandler booms, so we are, I think referring to telescopic booms on such items as manlifts or aerial lifts. Lines gouged perpendicular to the longitudinal axis of the boom signifying to me that boom elements within their outer boom elements have contacted (metal to metal) the bottom edge of the outer boom openings during lifts. There should be be wear pads whithin these boom segments and either, these wear pads are missing or badly worn out.

 

[Walterke]

Chicopee
That was our first thought, and that's exactly what they look like.
Unfortunately, the position of the lines doesn't add up to where they would be should the wear pads be worn out/missing.


to all:
Thanks for all the info (even the fortune telling part). I know I am not giving enough info for you people to solve this problem, but I was more looking for places I could search, then for an actual answer to my problem.

@BigTomHanks
Booms are cut out of steel plates, bent in U-shapes and welded together. No extrusion here. Thanks anyway though.

If anyone could suggest a none-destructive way of checking the material, that can be done in-situ, that would be awesome. (for now, I said: mark the lines, step way back, overcharge the machine, and see if the lines get bigger)

NX 7.5.5.4 with Teamcenter 8 on win7 64
Intel Xeon @3.2GHz
8GB RAM
Nvidia Quadro 2000

 

[Tmoose]

Are these parts painted?

I think some visual inspection of the "lines" with good light and magnification would be useful.
Dye penetrant inspection, and better yet fluorescent DPI might offer something , at least to determine if they are "wear" or perhaps material defects that have opened up because the plate was bent transversely (parallel to rolled grain) and the material started with a bunch of seams, etc.

http://t3.gstatic.com/images?q=tbn:ANd9GcRc9TkjJ0ciOnlLVOj1QXuliP-4S7rRQVmsfWzd94ag8M2PoGaF

http://michigantoday.umich.edu/2009/05/bendable-concrete.jpg

 

[MintJulep]

So your immediate interest is in finding what is causing the lines?

Fill them in with something like wax or spackle. Run machine. Look for little pile of wax or spackle.

 

[bigTomHanks]

Another shot in the dark. Since the lines look like typical wear lines, could it be possible that something happened to the machine, a service was performed and the cylinder was rotated so that good material was contacting the wear location. In this situation the customer knows what's going on and now is trying to get a warranty claim.

 

[chicopee]

Since the actual damage has not been clearly identified, I'll take another shot at guessing. You told us that the damage is on the boom segement compression side close to the boom pin, it is possible that when the boom first segment is resting and there is contact with the machine structure, every time someone would hop on the basket which then the boom would vibrate up and down, the boom would get scored more and more.