ISO 14692 - Buckling calculation

In order to satisfy the requirement of ISO 14692 - Part 3, Section 8.7 meant for "Axial compressive load", is there any method to refer axial compressive forces from CAESAR II output? Could anyone address on this?

Hi Thiagarajan

I suggest you can pick the critical axial stress data from standard report "stress extended" for the load case operating & sustain.
Last time I follow UKOOA code there was needed to compare axial stress V/s hoop stress.
If you required Axial load may be you can multiply axial stress with area, or just creating a cnode at that particular point to find out axial laod.

May be you can follow global element force extended.

Regards

Habib

The column labeled fx in the Local Forces & Moments Report (as opposed to FX in the Global F&M report) is the axial stress in that element. A positive value is tension, a negative value is compression.

Hi Dave
Thanks for your comments. Yes we need to consider local element fx for axial load.

Regards

Habib

From the local element forces & moments, + ve sign indicates value along postive local x axis and - ve sign indicates value opposite to that of positive local x axis. Hence, + ve sign may be compressive or tension in nature depending on the expansion / contraction behaviour of the system. That is why I am unable to depend on the sign alone. Is there any other method to pick compressive force directly from the CAESAR II output?

Hi Thiagarajan

Don't you understand Dave's comments "A positive value is tension, a negative value is compression"

Where from you got idea "+ ve sign may be compressive or tension in nature depending on the expansion / contraction behaviour of the system"

Hi Shr,

I am sorry that I differ with you. For local co-ordinate system, refer the Technical reference manual in Fig 11 clearly explains about local co-ordinate definition. Considering the example given in Fig 11, if anchor is placed at Node 30 and at Node 40 fx is positive, the force is tension in nature. On the other hand, if anchor is placed at Node 40 and fx is positive, the force is compression in nature. That is why I was enquiring whether it is possible to get the compressive load directly from CAESAR without considering the sign value of fx.
I prefer to have good technical discussion / feed back without using HARSH language.

Thiagarajan,

I do not see a Figure 11 for Local F&M in the Technical Reference Manual.

That "fx" in the Local F&M report is the axial force with respect to the pipe. Positve fx is pointing from the From Node and pointing to the To Node. C2 reports element F&M's in pairs - the From Node and the To Node. You should see equal and opposite axial loads on either side of the element.

If fx for the To Node load is positive (and the From Node is negative), the pipe is in tension - your load is directed away from the element. If fx is negative for the To Node (and the From Node is positive), the pipe is in compression - your load is directed towards the element.

You are right, what I posted earlier was incomplete. But if you only consider the To Node, it works just fine.