Hello to everybody.

I have a calculation model relevant to a subsea pipeline with concrete coating affecting bending stiffness.
According to client indication, bending stiffness of the system (piping+concrete) should be increased by a certain factor >1 in comparison to bare pipe.
The only way I know to do this is increasing pipe thickness in order to reach the required value of pipe moment of inertia, but this will affect also axial and torsional stiffnesses.

Does anybody know if there is the possibility to specify a flexibility factor < 1 in order to increase bending stiffness for the whole piping system?

Thanks in advance.

The bend flexibility factor appears in a number of terms in the bend stiffness matrix. You can adjust this, but it will affect more than bending.

Richard thanks for your answer, from which I understand that, if desired, flexibility factor can be adjusted for bends, but nothing can be done about straight pipe run.

Am I correct?

Thanks in advance.

Regards

Correct, the input for the (bend) flexibility factor will only affect bends. Others who have faced this problem have modified "E" (the elastic modulus) to account for the combined material cross section. (There is an old paper from Stone & Webster on this idea. You should be able to find this on the Internet.)