Dear All,

Currently I am using PV Elite 2006 to design a saddle support during shipping using G-loading : Gx = 0.28, Gy = 0.68 7 Gz = 0.57.
However, I have some queries that I very appreciate if you could advise which are as follows :

1)Saddle Reaction Force due to Earthquake Fl or Friction
Fsl = Max (Fl, Friction Force, Sum of X Forces)*B/Ls
a)How is Fl calculated and does it include G-loading value?

2)Saddle Reaction Force due to Earthquake Ft
Fst = Ftr*(Ft/Num of Saddles + Z Force Load)*B/E
a)What is Ftr? Where can I change this Ftr value?
b)How is Ft calculated and does it include G-loading value?

3)Load combination Results for Q+Wind or Seismic
c)Q = Saddle load+Max(Fwl,Fwt,Fsl,Fst)
d)How is saddle load calculated and does it include G-loading value?

4)Total Saddle Load
In saddle calculation output
Left saddle load = 1182098 N
Right saddle load = 927329 N
Total saddle load = 2109427 N = 215100 kgf

In weight summary output
Fabricated / Empty Weight = 120624.4 kg
Operating weight = 144784.4 kg

a)Why total saddle load different from empty weight / operating weight?

I much appreciated anyone kind respond and advise on above matter.

Thanks & Regards,
koleque

Can anybody help me here?
I most appreciated.

Regards,
koleque

Dear Koleque,

I will try to answer your questions,

1)Saddle Reaction Force due to Earthquake Fl or Friction
Fsl = Max (Fl, Friction Force, Sum of X Forces)*B/Ls
a)How is Fl calculated and does it include G-loading value?

==> Fl should be operating weight of the saddle times the "gx" X-component of the acceleration. Fl is in the longitudinal direction and is assumed to be taken by 1 saddle (other saddle is sliding).


2)Saddle Reaction Force due to Earthquake Ft
Fst = Ftr*(Ft/Num of Saddles + Z Force Load)*B/E
a)What is Ftr? Where can I change this Ftr value?
b)How is Ft calculated and does it include G-loading value?

==> Ftr is the factor to convert horizontal force to a vertical load on the saddle. It is an input parameter "Moment factor" on the saddle dialog, the recommended value is 3. Review the help entry for this field.

==> Ft should be load in the transverse direction. It is the vessel weight times gz.


3)Load combination Results for Q+Wind or Seismic
c)Q = Saddle load+Max(Fwl,Fwt,Fsl,Fst)
d)How is saddle load calculated and does it include G-loading value?

==> The gy is the vertical saddle load, it is combined with the weight load on the vessel. You should also run an additional case with -gy acceleration. This will add to the vessel weight.


4)Total Saddle Load
In saddle calculation output
Left saddle load = 1182098 N
Right saddle load = 927329 N
Total saddle load = 2109427 N = 215100 kgf

In weight summary output
Fabricated / Empty Weight = 120624.4 kg
Operating weight = 144784.4 kg

a)Why total saddle load different from empty weight / operating weight?

==> the weight of the saddle is not acting on the vessel. It can also be modified by the gy component.

Dear Mandeep,

Thank you very much for your respond.

Recommended Ftr value is 3. In Mr. Moss book also mentioned this as 3. However,it is possible to reduce it to 1?
In what condition value 1 will occured?

Appreciated your respond.

Thanks & Regards,
Rosdi

Further to the above, may I ask if anyone can share the original paper by L.P. Zick or recommand the articles with more detail about Zick's Analysis except those in Pressure Vessel Design Manual or Process Equipment Design?
Appreciate if anyone can email this to me at koleq@yahoo.com

Thanks & regards,

rosdi

Dear Mandeep,

Forgot to mentioned in above post that I would like to use Ftr = 1 for designing transportation saddle. Is it possible?

Secondly, as mentioned in other post for; Q = saddle load + max (Fwl, Fwt, Fsl, Fst); saddle load is excluding saddle weight. However, base plate design take this Q value to check the base plate thickness.
In my opnion, saddle weight has to be considered in the design of the saddle base plate. Why PV Elite does not considered this?

Please advise or correct me if I'm wrong.

Sorry I've ask so much question since I am beginner in PV Elite software design.

Thanks & appreciate your respond.
koleque

Ftr = 3 is correct and cannot be 1. Try google for international forum discussions regarding this number and Dennis Moss's manual. Look in the eng-tips forum for guidance.