Wheel loading analysis on crane runnway beam 5

[tnteng]

Can anyone lead me to a reference that gives allowable stresses on an I-beam flange due to wheel loading from a bridge crane end truck.

Thanks in advance for any help.

Tony Billeaud
Mechanical Engineer

 

[BENDOG]

Try American Iron and Steel Engineers(AISE)Technical Report No.13 "Guide for the Design and Construction of Mill Buildings". The AISC Steel Design Guide No.7 on Industrial Buildings is another.

 

[ahunt]

Check out the Modern Steel magazine on the AISC website. Here's a link to an artical in steel exchange from December 1999 on calculating bottom flange capacities.

http://www.aisc.org/MSCTemplate.cfm...tomSource/Faq/SteelInterchange.cfm&FaqID=1976

 

[CanuckMiner]

tnteng,

Check Crane Manufacturers Association of America (CMAA) Specification #70 and/or #74. Spec 70 is for multiple girder top running cranes, #74 is for top or under running single girder cranes.

Both documents give load combination criteria and allowable stress ranges based on Crane Class.

Website...

http://www.mhiastore.org/category.cfm?Category=39

Cheers,
CanuckMiner

 

[dozer]

In my opinion that AISC article is grossly oversimiplified. CMAA Spec. Nos. 70 and 74 both have a detailed design guide for the local bending of flanges due to wheel loads. It's not for the casual user though. You actually need to understand solid mechanics to understand what it is you are looking at.

 

[tnteng]

ahunt,

Thanks for the link. Can you give any input on the difference between the formulas used on the website you provided and those in section K.1.2 and K.1.3 of the AISC ASD spec.

Thanks,

Tony Billeaud
Mechanical Engineer

 

[ahunt]

K1.2 refers to local flange bending, it's a check to see if you need to provide stiffeners on a column due to a gusset pulling at the flange. The stiffeners are required according to k1.2 if the flange is thinner than

0.4*(Pbf/Fyc)^1/2

Where Fyc is the column yield stress in ksi, and Pbf is the computed force to the flange times 5/3.

K1.3 is for local web yielding, if you are away from the end of the member by more than the depth of the member, the following applies:

R/(tw*(N+5k) < 0.66*Fy

R is the reaction
tw is the web thickness
N is bearing length
and k is distance from outer face of flange to web toe of fillet.

This is from AISC ASD 9th edition. You can get the latest spec from AISC's website for free. It's updated for strength level design rather than allowable stress methods.