Topic Options
#6954 - 08/20/01 05:59 AM Vessel/Nozzles centerline direction cosines
Yoshida,Gilberto Offline
Member

Registered: 08/20/01
Posts: 7
Loc: Brazil
I'm having some difficulties to run wrc 107 program in coadecalc when entering the loads from Caesar II global coordinates, so I hope somebody could give me some tips.
The problem is the following:
When I enter the loads in the wrc 107 convention I don't get the stress summations, so I'm entering the loads in global coordinates. But the problem is that I'm not felling confident of entering the direction cosines rigthly since I didn't understand the convention described in the user's guide.
I just know that the nozzle vector is always defined to point to the centerline of the vessel. But what is the convention I have to use, for instance, when analying a horizontal vessel with a nozzle on the shell?
And another situation is when I have a nozzle on the head. What is the vessel direction cosines?(I know that it can't be colinear with the nozzle centerline.)

Regards,
_________________________
Gilberto Yoshida
Engineering
Construtora Norberto Odebrecht

Top
#6955 - 08/21/01 09:42 AM Re: Vessel/Nozzles centerline direction cosines
Mandeep Singh Offline

Member

Registered: 12/15/99
Posts: 600
Loc: Houston, Tx, USA
The direction vector for a nozzle is along the nozzle centerline pointing towards the vessel. For a cylinder or a cone, the direction vector is along the vessel centerline. The +/- direction does not matter, as it will only have the effect of switching the location of the A, B points.

For a spherical vessel the direction is tangent to the vessel at the nozzle-vessel junction. Since WRC-107 only addresses 90-degree nozzles, hence the nozzle and vessel direction vectors will not be collinear.

It helps to draw the vessel, axis, nozzle and the loads all on 1 page and then figure the direction vectors from there.

Program converts the global loads to the WRC system before doing the stress computations. A good check is to check the loads in WRC convention from the output.

Regards,
Mandeep
_________________________
Best Regards,
Mandeep Singh
CADWorx & Analysis Solutions
Hexagon PPM

Top



Who's Online
0 registered (), 26 Guests and 1 Spider online.
Key: Admin, Global Mod, Mod
May
Su M Tu W Th F Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
Forum Stats
12065 Members
14 Forums
16973 Topics
75151 Posts

Max Online: 303 @ 01/28/20 11:58 PM
Top Posters (30 Days)