Crane - Telescopic boom calculation 2

[Muon1]

Hi All,

I've been asked to calculate the bending moments of a 4 stage telescopic boom. I've looked at the BS ISO standards for crane design but there's nothing about a telescopic crane. The crane has to pickup 500kg's using a grab at the max extension of 4m (horizontal).

Can someone please direct me to some relevant info (examples, standards, etc) please.

Regards

Muon.

 

[desertfox]

This link might help

http://ijmerr.com/ijmerradmin/upload/ijmerr_4ff308efb75dd.pdf

 

[dhengr]

Desertfox.... That link looks like a real good example of a telescoping boom for him to chew on. He has to know much more about the exact make-up of the boom construction if he is going to do a complete job. And, he might look for the crane boom/load charts which are part of the operators manual. They will help him pin down the manufacturer’s design criteria.

 

[Muon1]

Thanks desertfox.

I spoke to a stress engineer today, and he's given me a rough idea how to tackle the problem. I was having trouble of how to work out the bending moments on the sliding joints (were the stages overlap). It seems that the stages can be modeled as lever arms. All I need to do now is work out if the stainless steel rectangular hollow sections (the stages) will take the 500kg load.

 

[desertfox]

Hi Moun1

You're very welcome.

 

[chicopee]

Your OP puzzles me because manufacturers will incorporate load charts in their cranes regardless of the types ,i.e., telescoping booms or lattice booms. So whatever your answer turns out to be, it will be a lot different than that provided by the manufacturer. Also don't forget that load charts are broken down in two categories of failure being overturning the crane or structural failure of the boom when lifting loads. Load charts are further broken down for load ratings, on tires, outriggers fully extended, travelling. There are further break down of load charts for lifting loads, so get a book on cranes and one author that I have read in the past was Shapiro's " Cranes and Derricks"

 

[mecheng1001]

The design standard for telescopic cantilever crane boom is SAE J1078. I have attached an old version which should be sufficient.

 

[chicopee]

A quick review of SAE J1078 lead me to believe that only the structural aspect of the boom is being addressed, however, it does not cover the issue of crane stability while lifting which load charts would also cover.