Lifting Beam Design to BS13155:2020

[JLC123]

thread507-502446
@jedstress
I am struggling to interpret the requirements of BS13155:2020 for a lifting beam design. The thread referenced above asked the same questions I am struggling with, but without a resolution. I am hoping the original poster (jedstress) might read this thread and share the conclusion he come to and how he came to it.
Thanks.

 

[JAE]

Bump - anyone?

 

[human909]

Rather than bumping, if you are interested in the answer it might be a good idea to make the question extremely clear. Having to click through to another thread and read that isn't clear.

 

[JLC123]

Thanks for the responses. Below is the original question posted by @jedstress. I am struggling with the same issue. The lifting beam will be designed for less than 16,000 load cycles.

I am currently working on a lifting beam which has to be designed/analysed in accordance with BS13155:2020.

The following is an extract from bs13155:2020 Annex A:

"A.1 Verification of mechanical strength by calculation
The mechanical strength shall be proven for the specific working load limit in accordance with EN 13001-3-1.
The maximum permissible tilting angle specified for the attachment shall be taken into account in calculations.
The design load used in calculations shall be derived using coefficients as given in 5.1.2 and 5.2 for both yielded and elastic conditions.
The mechanical strength shall be calculated in accordance with EN 13001-1 and the limit design stress shall be in accordance with:
— for the elastic condition, the allowable stress method;
— for the yielded condition, the limit state method."

§5.1.2 states that:
"5.1.2.1 Load lifting attachments designed for a maximum of 16 000 load cycles
— Elastic condition: the mechanical load bearing parts shall be designed to withstand a static load of two times the load they are required to sustain under the intended operating conditions without permanent deformation.
— Yielded condition: the mechanical load bearing parts shall be designed to withstand a static load of three times the load they are required to sustain under the intended operating conditions without releasing the load even if permanent deformation occurs.
The coefficients mentioned above cover the uncertainties of the value of the actual load and the impact factor for hoisting a grounded load (dynamic effect) in general applications. The proof of fatigue strength is not necessary, it is covered by the global safety of the proof of static strength."

As stated above, and referring to BS 13001-1, the limit state method for the yielded condition mentions dynamic factors, partial safety factors and risk coefficients to be applied to the applied loads.

So, based upon §5.1.2 (above), is BS13155 suggesting that these individual load factors/risk coefficients etc (from BS 13001-1) be replaced by a single load factor of 3 for the yielded condition? And the limit design stress (allowable stress) is material Ftu/1.10?
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