Stress Analysis, sway braces

[samuelo]

Hi:

I'm in a new work, and my first task is to survey a pipe support installation on a ship. The question is that there are several supports, called sway-braces (Lisega is the manufacturer). I know how they work, but:

1. How are they modelized in a stress analysis?

2. I have the analysis already done. There I can see the movements of the node where the sway-brace is put. Should the sway-brace be calibrated to that movements? I mean, I have the loads, the displacements and the stiffness of the hanger; should the hanger accomplish with F=-kx?

3. What's gooing on if the travel of the spring in the sway-brace is not according to the displacements shown in the stress analysis?

I hope you can tell me something about this, I'm really confused.
Thank you very much

 

[LSThill]

Hi samuelo (Marine/Ocean)

Referenct to Mr. John Breen

Hello All,

Call me dense, but I only now became aware of a recently released MSS (Manufacturers Stardardization Society of the Valve and Fittings Industry) Standard:

Bracing for Piping Systems Seismic-Wind-Dynamic Design, Selection, Application
MSS, SP-127-2001, $55.00

I wanted to pass this along to the group in case I am NOT the last one to discover this Standard. This should be useful for application with the B31 Standard for Seismic Design (B31S, Standard for the Seismic Design and Retrofit of Piping Systems) that is currently being voted upon by the B31 Mechanical Design Technical Committee.

While you are at the MSS web page:

http://normas.com/MSS/index.html

You might want to consider other hanger/support/restraint Standards for your library:

SP-58-1993 Pipe Hangers and Supports -- Materials, Design and Manufacture

SP-69-1996 Pipe Hangers and Supports --
Selection and Application

SP-77-R2000 Guidelines for Pipe Support Contractual Relationships

SP-89-1998 Pipe Hangers and Supports -- Fabrication and Installation Practices

SP-90-2000 Guidelines on Terminology for Pipe Hangers and Supports

Best regards, John Breen

Leonard@thill.biz

http://www.thill.biz

 

[LSThill]

Hi samuelo (Marine/Ocean)

THE MARINE TECHNOLOGY DIRECTORATE

http://www.mtd.org.uk/pubs.html

99/100 Guidelines for the Avoidance of Vibration Induced Fatigue in Process Pipework

Leonard@thill.biz

http://www.thill.biz