BS ISO 13586:2018 pdf download

BS ISO 13586:2018 pdf download.Plastics — Determination of fracture toughness (G IC and K IC ) — Linear elastic fracture mechanics (LEFM) approach
1 Scope
This document specifies the principles for determining the fracture toughness of plastics in the crack- opening mode (mode I) under defined conditions. Two test methods with cracked specimens are defined, namely three-point-bending tests and compact-specimen tensile tests in order to suit different types of equipment available or different types of material. The methods are suitable for use with the following range of materials, including their compounds containing short fibres of the length ≤ 7,5 mm: — rigid and semi-rigid thermoplastic moulding, extrusion and casting materials; — rigid and semi-rigid thermosetting moulding and casting materials. In general, short fibre lengths of 0,1 mm to 7,5 mm are known to cause heterogeneity and anisotropy in the crack tip fracture process zone. Therefore, where relevant, Annex B offers some guidelines to extend the application of the same testing procedure, with some reservations, to rigid and semi-rigid thermoplastic or thermosetting plastics containing such short fibres. Certain restrictions on the linearity of the load-displacement diagram, on the specimen width and on the thickness are imposed to ensure validity (see 6.4) since the scheme used assumes linear elastic behaviour of the cracked material and a state of plane strain at the crack tip. Finally, the crack needs to be sharp enough so that an even sharper crack does not result in significantly lower values of the measured properties.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles
ISO 604, Plastics — Determination of compressive properties
ISO 2818, Plastics — Preparation of test specimens by machining
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.4 critical stress intensity factor
value of the stress intensity factor (3.3) when the crack under load actually starts to enlarge under a plane-strain loading condition around the crack tip
Note 1 to entry: It is expressed in Pa × √m.
Note 2 to entry: The critical stress intensity factor K IC of a material is related to its critical energy release rate GIC by the formula: