Introduction:
For cathodic protection of subsea pipeline, the distance between Lowest Astronomical Tide (LAT) and Highest Astronomical Tide (HAT) is about 80 meter, and the subsea pipeline is buried before shore line into onshore (presuming for the subject length it is buried in both offshore...
DNV-RP-F102 calls the Field Joint Coating (FJC) applicable on the steel cleanliness of Sa2 1/2 treated by blast cleaning. In offshore FJC is applied on the pipelaying barge, and the field joints are not blast cleaned (there is not blasting station on pipelaying barge, and the field joint are...
Thanks APipeliner, I will run a FEM considering concrete stiffness effect. (I had run a simple beam without concrete and the FEM and manual results were nearly the same)
In F105 Sec. 6.2.3 it is quoted “the positive effect on the stiffness and strength is normally disregarded”, of course the...
Introduction:
Ref. DNV-RP-F105(Feb 2006) for subsea pipeline free span analysis, I want to calculate STATIC vertical soil stiffness.
I understand there are 2 methods to calculated it as follows:
1)Simple method is to use table 7-5 / 7-6
2)Based on static vertical soil reaction sec 7.4.1 to...
Introduction:
Ref. DNV-RP-F105(Feb 2006) for subsea pipeline free span analysis, I want to calculate the DYNAMIC lateral/vertical soil stiffness. Since the calculated specific mass ratio between the pipe mass and displaced water is not in the range of 1.2 and 2, the formula in sec 7.4.10 can not...
In ANSYS, I wanted to carry out a STATIC analysis (load step 1, using LSWRITE command) (NLGEOM is on) and maintaining the same results to go on MODAL analysis (load step 2, using LSWRITE command). However it is not possible. Can somebody advise how it is possible to do this modeling in ANSYS...
Thanks Gurmeet, it depends how the modeling is done, what you said is generally correct provided that (i think) the modeling is near to reality and simplification is reduced, for instance in case a subsea pipeline (with concrete) is modeled by solid elements (not beam elements as is normal...
To carry out bottom roughness analysis (subsea pipeline on seabed), I use ANSYS, and for this purpose I use a pipe element (e.g. Pipe20) along with a gap contact element (e.g. contac52) based on the bathymetric data (geophysical survey) and writing a program file (macro) and defining various gap...
For pipe modeling I need to apply stress concentration in pipe model. In ANSYS the element Pipe20 allows stress concentration in the bending, however I do not know how to model stress concentration in ABAQUS (in ABAQUS i use Pipe21 or Pipe31 element). Kindly advise.
Regards,
Amir
Introduction:
To carry out free span analysis (DNV-RP-F105 Feb 2006)for subsea pipeline, at 1st bottom roughness analysis is done to identify the span length and gap, and also moments and effective forces (or stresses/ strains) along the pipeline for various phases (as laid, flooding, hydro...
For wall thickness calculation as per DNV-OS-F101, the follwoings shall be checked:
1) Pressure containment (buresting)
2) Local buckling - external over pressure only (system collapse)
3) Propagation buckling
In general local buckling - combined loading criteria should be checked in other...
