Dear Habib,

Forces,moments and movements could be found from header analysis report to include them into branch analysis but how will you get stiffness values from header analysis report and most important how you will input it in caesar II.

The header-branch analysis as two seperate analysis is a common situation encountered by every stress engineer.

The general practice is first to analyse header portion considering branch disconnected with it and note down the displacements at branch connection point.While anlysing branch portion at that time define the earlier noted displacements at the branch connection with applicable SIF and evaluate stress at the connection point.

Stiffness is a system property and depends on modulus of elasticity,cross-sectional area,thickness and length of piping element for any simple piping system including header-branch configuration.

We incorporate stiffness of the system by modelling branch piping with portion of the header upto first support on either side of branch.

My question is why we do not consider forces and moments together with displacements to evaluate stress at the connection point.

Explanation supported theoritically will be highly appreciated.

Regards,
Aslam