Surface embrittlement of polyethylene pipe-grade resins. Final report, september 1, 1979-july 1, 1986

Technical Report · Sun Mar 01 04:00:00 EST 1987

OSTI ID:5494874

Broutman, L J

A specimen has been developed which simulates the behavior and failure modes of polyethylene pipe subjected to sustained internal pressure. The specimen is uniaxially tensile loaded, but surface grooves constrain deformation producing a plane strain state in the grooved area which results in a stress state simulating that of internally pressurized pipe. When this specimen is subjected to a constant tensile load as in a creep rupture test, a ductile-brittle transition occurs agreeing closely with transition times measured for pressurized pipe. This specimen offers many advantages including the ability to observe visually the microscopic nature of the failure process during test. Of most importance, the specimen lends itself to controlled and uniform surface embrittlement (e.g. by ultraviolet radiation), so that its influence on lifetime can be easily determined. Results to date show that for a medium density pipe grade resin, the ductile-brittle transition time can be reduced by a factor of at least three when the surface is embrittled by U.V. radiation.

• Research Organization: Illinois Inst. of Tech., Chicago, IL (United States)
• OSTI ID: 5494874
• Report Number(s): PB-91-194373/XAB
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
032000* -- Natural Gas-- Transport
Handling
& Storage
36 MATERIALS SCIENCE
360603 -- Materials-- Properties
AGING
CREEP
DEFORMATION
DENSITY
DUCTILE-BRITTLE TRANSITIONS
ELECTROMAGNETIC RADIATION
EMBRITTLEMENT
ENERGY SYSTEMS
FAILURE MODE ANALYSIS
FAILURES
FRACTURE MECHANICS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
MECHANICS
NATURAL GAS DISTRIBUTION SYSTEMS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PHYSICAL PROPERTIES
PIPES
POLYETHYLENES
POLYMERS
POLYOLEFINS
PRESSURIZATION
RADIATIONS
RUPTURES
SERVICE LIFE
STRAINS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TENSILE PROPERTIES
TESTING
ULTRAVIOLET RADIATION
WEATHERING