sacs 1

[mohammed43]

Hello All,

I have civil engineering experience & recently switched to offshore (esp design of hull structures(lift boats))..
Can anyone guide me some material for lift boats design, I know that there are ABS, DNV guides. But Iam looking for some basic indetail material..

Also I started learning SACS, I couldnt understand the pupose of wish bone element. Can someone plz explain the concept..

Thanks

 

[London]

I can help with the SACS question.

A wishbone element is a normal element that is preconfigured to provide restraint for lateral forces local to the element (local y and z axes). This is used to connect two elements together, allowing them to slide past one another.

A typical example - Riser in a guide support. Riser is allowed to expand vertically and free to rotate, but restrained laterally.

You need coincident joints to create a wishbone, and also a third joint along the line to be created. The program offsets one end from one coincident joint to the direction of the local (x) axis, and therefore the and (z) axes for the restraint.

Treat is as a normal member otherwise, ie, flood and override the drag on the member as appropriate to avoid double dipping.
The SACS manual has more information on wishbones.

 

[mohammed43]

Thanks London!!

As I mentioned earlier Iam new to offshore field and also to SACS..

If we want to restrain or release members then why cant we use member release options (111000 or 000111). I tried searching SACS manual before asking for help but couldnt get much info in the manual. May be I didn't looked in the right place..

Can you please elaborate ...

Thanks

 

[London]

No Problem!

Yes, you are right in asking if you can restrain or release members. In effect, this is what SACS does. The wishbone is a preconfigured element, with appropriate member releases and densities already applied. The same can be achieved by manually changing the element properties.

The manual is a little archaic in places, I agree.

Regards