Journal of Applied Mathematics / 2012 / Article / Tab 1

Research Article

A Theoretical Approach to Predict the Fatigue Life of Flexible Pipes

Table 1

Possible contact pressures and stress in the high-strength (HS) tape for a typical unbonded flexible pipe considering different annulus conditions and axisymmetric loading.

ShapeInterface Stress (HS tape) Annulus
12345

1ContactContactContactContactContactUnloaded
2No contactContactContactContactContactTensioned
3No contactContactContactContactContactUnloaded
4No contactContactContactNo contactContactTensionedDry
5No contactContactContactContactNo contactUnloaded
6No contactContactNo contactNo contactContactTensioned
7ContactContactContactContactNo contactUnloaded

8ContactContactContactContactContactUnloaded
9No contactContactContactContactContactTensioned
10No contactContactContactContactContactUnloaded
11No contactContactContactNo contactContactTensioned
12No contactContactContactContactNo contactUnloadedFlooded
13ContactContactContactContactNo contactUnloaded
14ContactNo contactContactNo contactContactTensioned
15ContactNo contactContactContactNo contactUnloaded
16Pure external pressure

Interface 1: inner carcass and internal plastic sheath; interface 2: internal plastic sheath and pressure armor; interface 3: pressure armor and antiwear tape (or tensile armor); interface 4: pressure armor (or antiwear tape) and internal tensile armor; interface 5: external tensile armor and polymeric layer upon it. In all other interfaces, contact between layers was observed.