ISO 18489:2015
Polyethylene (PE) materials for piping systems — Determination of resistance to slow crack growth under cyclic loading — Cracked Round Bar test method
Polyethylene (PE) materials for piping systems — Determination of resistance to slow crack growth under cyclic loading — Cracked Round Bar test method
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 11
- Дата публикации:
- 2 сентября 2015 г.
- Издание:
- ISO IS 18489 edition 1 version 1
- ICS:
- 23.040.20
ISO 18489:2015 specifies a method to determine the resistance to slow crack growth (SCG) of polyethylene materials, pipes, and fittings. The test is applicable to samples taken from compression moulded sheet or extruded pipes and injection moulded fittings of suitable thickness. ISO 18489:2015 provides a method that is suitable for an accelerated fracture-mechanics characterization at ambient temperatures of 23 °C of different polyethylene grades, especially for PE 80 and PE 100 types for pipe applications. NOTE This test method could be adapted for other thermoplastics materials by developing the procedure using different test parameters.
Abstract
Overview
ISO 18489:2015 specifies the Cracked Round Bar (CRB) test method to determine resistance to slow crack growth (SCG) in polyethylene (PE) materials for piping systems. The standard defines an accelerated fracture‑mechanics test performed at ambient temperature (23 °C) suitable for PE pipe grades-especially PE 80 and PE 100-and for specimens taken from compression‑moulded sheets, extruded pipes and injection‑moulded fittings. The method can be adapted for other thermoplastics by adjusting test parameters.
Key topics and technical requirements
- Test principle: cyclic tensile loading with a constant load range on a cylindrical specimen containing a circumferential razor‑sharp notch to promote crack initiation and SCG to final failure. Final result is failure cycles (Nf) as a function of initial crack length and stress range.
- Specimen geometry: preferred specimen diameter D = 14 mm and length L = 80–100 mm. Target initial crack length a* = 1.50 +0.15/‑0.0 mm, producing a target initial ligament diameter D*.
- Notching: notch tip radius
Технические детали
- Технический комитет
- ISO/TC 138/SC 5 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
- SKU
- ISO 18489:2015
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