Steel wire mesh skeleton polyethylene composite pipe slow crack growth resistance test method

Abstract

The invention discloses a steel wire mesh skeleton polyethylene composite pipe slow crack growth resistance test method and belongs to the polyethylene composite pipe test tooling technology field. Asteel wire mesh skeleton polyethylene composite pipe is a composite layer structure and comprises an inner and outer polyethylene layer. The test method comprises an outer layer slow crack growth resistance test and an inner layer point load crack growth resistance test. The method has advantages that dual tensions promoting crack growth are provided in a mechanical force and a hydrostatic test, alength of crack growth is recorded and is compared with an initial length, a slow crack growth resistance performance method in an inner layer of a composite pipe is evaluated, and an actual simulation in a complex external environment of the composite pipe is really simulated; and a special tool for making a notch in the inner layer of the composite pipe and a tooling capable of providing a point load in the inner layer of the composite pipe are provided. .

Description

[0001] Technical field: [0002] The invention belongs to the technical field of polyethylene composite pipe testing tooling, and more specifically relates to a test method for slow crack growth resistance of polyethylene composite pipes with steel mesh skeletons. [0003] Background technique: [0004] At present, the known HDPE pipes require resistance to slow crack growth. The wall thickness e≤5mm (cone test) is based on GB / T19279-2003, and the wall thickness e>5mm (notch test) is tested according to GB / T18476-2001. , has formed an international general standard and accurately evaluated the crack growth resistance of HDPE solid-wall pipes, and thus produced HDPE solid-wall pipe products with high resistance to slow crack growth. For HDPE pipe products in trenchless, original The promotion of application fields such as soil backfill has a good promotion effect, and effectively improves the service life of the pipe. [0005] Polyethylene composite pipe with steel mesh skel...

AI Technical Summary

Problems solved by technology

[0014] The first technical problem to be solved is: at present, it is not only the damage of the outer wall that affects the crack growth performance of the pipe, but the damage of the inner wall has not been paid attention to. However, the damage of the inner wall is under the action of external mechanical force and the working state of high pressure. Under this condition, the crack growth of the pipe is a problem that cannot be ignored;

[0016] The third technical problem to be solved is: apply a point load, that is, an inward mechanical force to simulate external force to promote crack growth. When encountering conditions such as hydrostatic test pressure increase and temperature increase, deformation and displacement are easy to occur, and it is impossible The problem of measuring the depth of the sinking pipe body and adjusting the depth according to the test requirements

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