Abstract

Fracture mechanics tests according to British Standard 3505 have been made on two unplasticized polyvinyl chloride (uPVC) pressure pipes. The applied load was varied and time to failure was measured as a function of load. The results were fitted to an empirical power law, using the concepts of linear elastic fracture mechanics, relating crack growth rate, v, to the stress intensity factor, K1, according to v = A K1, where , where A and α are α constants. The parameters A and α were then applied to uPVC pipes provided with assumed Flaws of different sizes and shapes, and lifetime was calculated as a function of internal pressure.

Close agreement with published ductile failure data of uPVC pipes were obtained for elongated, axial flaws on the inside wall, between 0.8 and 1.0 mm in size.

References

1.
BS 3505
1986
, Unplasticized Polyvinyl Chloride (uPVC) Pressure Pipes for Cold Potable Water.
2.
Marshall
,
J. M.
,
Marshall
,
G. P.
, and
Young
,
D. N.
, “
The Use of Fracture Mechanics in the Development of Tough Polymers for Use in Water Distribution System of NWWA
,” in
Plastic Pipes VII
.
International Conference
,
Bath University
,
UK
.
1988
, pp. 40.1-40.6
3.
Truss
,
R. W.
, “
Temperature Derating of Unplasticized Polyvinyl Chloride (uPVC) Pressure Pipes
,”
Plastic and Rubber Processing Applications
, Vol.
7
,
1987
, pp.
51
-
56
.
4.
Truss
,
R. W.
, “
Understanding Brittle Failure of uPVC Pipe
,”
Pure and Applied Chemistry
 0033-4545, Vol.
57
, No.
7
,
1985
, pp.
993
-
1000
.
5.
Brock
,
D.
,
Elementary Engineering Fracture Mechanics
Noordhoff, Leyden, The Netherlands
,
1974
.
6.
ABAQUS, Hibbitt, Karlsson & Sorensen, Inc.
, 100 Medway Street, Providence, RI 02906.
7.
Marshall
,
G. P.
and
Birch
,
M. W.
, “
Design for Toughness in Polymers 3—Criteria for High Toughness in uPVC Pressure Pipes
,”
Plastic and Rubber Processing Applications
, Vol.
2
,
1982
, pp.
369
-
379
.
8.
Williams
,
J. G.
,
Fracture Mechanics of Polymers
,
Ellis Horwood
,
Chichester, UK
,
1984
, pp.
149
-
151
.
9.
Roobe
,
D. P.
and
Cartwright
,
D. J.
,
Compendium of Stress Intensity Factors
,
Her Majesty's Stationary Office
,
London
,
1976
.
10.
Benjamin
,
P.
, “
Quality and Quality Control of Unplasticised Polyvinylchloride (uPVC) Pressure Pipes
,”
Plastic and Rubber Materials and Applications
,
11
1980
, pp.
151
-
60
.
11.
Gaube
,
E.
and
Kausch
,
H. H.
, “
Bruchteorien bei der industriellen anwendung von thermoplasten und glasfaserverstärkten Kunstoffen (Fracture Theories When Using Thermoplastics and Glass Fiber Reinforced Plastics in Industry)
,”
Kunstoffe
, Bd.
63
,
1973
, pp.
391
-
7
.
12.
Truss
,
R. W.
, “
Ensuring Satisfactory Service Life of uPVC Pressure Pipe Under Static Load
,”
Materials Forum
 0883-2900, Vol.
9
,
1986
, pp.
45
-
52
.
13.
Joseph
,
S. H.
and
Leevers
,
P. S.
, “
Failure Mechanics of uPVC Cyclically Pressurized Water Pipelines
,”
Journal of Materials Science
 0022-2461, Vol.
20
,
1985
, pp.
237
-
45
.
14.
Hitch
,
M. J.
, “
Structural Design in Thermoplastics, With Particular Reference to uPVC Pipelines
,”
Plastics in Southern Africa
,
12
1979
, pp.
21
-
27
.
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