OS-C501

Offshore Standard DNV-OS-C501, November 2013
Sec.14 Calculation example: two pressure vessels – Page 200
Table 14-24 Elastic ply properties
Property New component After 25 years in water
No matrix cracks No matrix cracks With matrix cracks in
±15 plies
±15 plies
E 1 fibre 23.7 GPa 21.3 GPa 21.3 GPa 21.3 GPa
E 2 matrix 7.6 GPa 6.8 GPa 0.08 GPa 0.08 GPa
ν 12 0.29 0.29 0.003 0.003
G 12 linear 3.2 GPa 2.9 GPa 0.03 GPa 0.03 GPa
±85 plies
E 1 fibre 23.7 GPa 21.3 GPa 21.3 GPa 21.3 GPa
E 2 matrix 7.6 GPa 6.8 GPa 6.8 GPa 0.08 GPa
ν 12 0.29 0.29 0.29 0.003
G 12 linear 3.2 GPa 2.9 GPa 2.9 GPa 0.03 GPa
6.2.3 Using properties of the laminate in water addresses possible diffusion of water into the laminate.
6.2.4 A load-model factor of 1.05 is chosen, for the same reasons as described in [5.2.4]-[5.2.5].
6.2.5 The following results are obtained from the stress and laminate theory analysis (without using a load
factor):
Table 14-25 Results for vessel for water without liner
Laminate
na: not applicable, since the matrix is cracked.
6.2.6 The component is checked for the pressure of: 1.48 MPa.
After 25 years in water, with
no matrix cracks
Pressure MPa 1.48 1.48
Diameter mm 250 250
Thickness mm 6 6
Average axial stress MPa 15.8 15.8
Average hoop stress MPa 31.6 31.6
E axial GPa 11.02 6.22
E hoop GPa 16.34 14.0
±15 o plies:
ε 1 % 0.108 0.233
ε 2 % 0.168 0.217
ε 12 % 0.035 0.009
σ 1 MPa 27.0 49.5
σ 2 MPa 13.9 NA
σ 12 MPa 1.01 NA
±85 o plies:
ε 1 % 0.17 0.216
ε 2 % 0.10 0.234
ε 12 % 0.01 0.003
σ 1 MPa 39.9 45.9
σ 2 MPa 10.7 NA
σ 12 MPa 0.35 NA
6.2.7 For each ply the local stress and strain components are applied in the failure criteria.
With matrix cracks in ±15
plies and ±85 plies
matrix cracks
DET NORSKE VERITAS AS