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jimbo2009 (Mechanical) (OP)
15 Sep 09 17:03
Hi, I have for the last few weeks dedicated a serious amount of time producing an Excel calculation table for EN 1591-3. I have managed to get so far but for some reason can not calculate FGΔ. Can anyone tell me what the max all I≠0 means in the calculation as im sure I am missing a trick here. Thanks
jimbo2009 (Mechanical) (OP)
15 Sep 09 17:45
Sorry its 1591-1,got confused with 13445-3 Annex G.
hartsa (Mechanical)
16 Sep 09 3:19
Hi,

I too spent quite a long time few years back in producing excel calcs according to EN13445-3 annex G. Nowadays there are commercial softwares such as VVD that does these calculations.

But calculating FGΔ according to EN1591-1 (equation 51) means that you have to calculate FGΔ in every subsequent condition and then the max value calculated is FGΔ.

For example: Subsequent conditions 1, 2, ...n

FGΔ1=(FG1min x YG1+(FQ1 x YQ1 +(FR1 x YR1 - FR0 x YR0)+ ΔU1)) / YG0

FGΔ2=(FG2min x YG2+(FQ2 x YQ2 +(FR2 x YR2 - FR0 x YR0)+ ΔU2)) / YG0

FGΔn=(FGnmin x YGn+(FQn x YQn +(FRn x YRn - FR0 x YR0)+ ΔUn)) / YG0

and finally

FGΔ = max(FGΔ1 ; FGΔ2 ; ... ; FGΔn)

Hope this helps...

Regards
Harri

 
jimbo2009 (Mechanical) (OP)
16 Sep 09 8:42
Thank you.
jimbo2009 (Mechanical) (OP)
16 Sep 09 15:17
If possible can some one give me some further clarification on the following from EN1591-1:

When checking the admissible loads in Section 6 if for example the conditions in the table state that ψZ=ψmax is ψmax calculated at Js=+1, ks=+1 and km+1. Also if the conditions state that ψZ=ψopt is ψopt calculated at Js=0, ks=0 and km=0. Thanks a lot for any help.


 
hartsa (Mechanical)
18 Sep 09 6:09
Hi,

Calculation sequence is presented after table 2 in the standard EN1591-1. When calculating for example ψmax, calculate ψmax with the equation 82 using js=+1, km=+1 and ks=+1. ψmin is calculated with js=-1, km=-1 and ks=+1 and so on.

Then you have to determine the value of jm (equation 80) and ψopt (83).

Finally for example if jm=+1 and ψopt >= ψmax, then km=+1 and ψz = ψmax.

I attached some example from calculation of integral flanges. I think that this was very useful when I did my calculations. It has all the required initial data to begin the calculations like dimensions, materials, etc. And there are results so that it was easy to compare my own calculations and this example. It should be reliable, one of our NB inspectors gave it to me.

Regards
Harri
     
jimbo2009 (Mechanical) (OP)
18 Sep 09 9:27
Thank you very much for an informative response once again and especially for the attached example which I will use to perform checks. I suspected that to be the case for ψz = ψmax, however my confusion came in the for of equation 84, which has no explanation but indicates that ψopt should equal ψ(0,0,0)??? I have produced my model after three weeks and just now checking that I have removed all potential errors. Thanks once again for your help.

Regards,

James
 

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