Hello all,

we have a underground FRP fire fighting pipe having design pressure of 25 bars.

I modelled the piping with caesar.

For to size thrust blocks at bends, and connections I need to calculate the loads on the thrust block.

How shall I treat the thrust block points in Ceasar. Should I treat them as anchor points and read the loads on this anchor restraint.

Or

buried piping model automatically places bilinear restraints. Should I read the loads on this bilinear restraints and use these loads for thrust block sizing calculations.

thanks in advance

saliba

Thrust Blocks should be modeled as anchors. CAESAR II of course doesn't know where you need (or will put) thrust blocks. So, after the model has been buried, edit the buried model and change the appropriate restraints to anchors.

I have placed thrust blocks to bend points.



My question is following:



Does Ceasar treats FRP pipe as if CS pipe.? CS pipes are modelled continuosly as far as I know. CS pipes are welded or flange connected.



Our FRP pipe has Adhesive taper joint, so at the test condition there is a possibility of failing at these joints. The joints can take apart.

Does Ceasar take into account this property of FRP pipe






Thanks in advance

The allowable stress in fiberglass pipes are subject to an interaction formula (i.e., longitudinal stress allowable is impacted by the level of the hoop stress in the pipe), but in adhesive joints it is not. For this type of joints, there a single limit for axial force and another limit for hoop stress, my colleagues in the field inform me that joint capacities are usually sized such that they are non-limiting (they are greater than the pipe capacities). So there are a couple of ideas:

• If the joint capacities exceed those of the pipe, don’t bother modeling them. Modeling everything as pipe will be conservative.
• If the joint capacities are limiting, then:
  1) Set up a node at the location of each joint, and use the extended stress report to ensure that the normal (bending plus axial) and hoop stresses are less than the joint allowables, or:
  2) Set up an anchor with CNODE at each location (so the joints are very easy to find) and then verify that the forces and moments are below the allowable stress.