ISO 21971:2019 pdf download.Fine ceramics (advanced ceramics, advanced technical ceramics) — Mechanical properties of ceramic composites at ambient temperature in air atmospheric pressure
1 Scope
This document specifies the conditions for the determination of hoop tensile properties of ceramic matrix composite (CMC) tubes with continuous fibre-reinforcement at ambient temperature in air atmospheric pressure. This document is specific to the tubular geometries since fibre architecture and specimen geometry factors in composite tubes are distinctly different from those in flat specimens. This document provides information on the hoop tensile properties and stress-strain response, such as hoop tensile strength, hoop tensile strain at failure and elastic constants. The information can be used for material development, control of manufacturing (quality insurance), material comparison, characterization, reliability and design data generation for tubular components. This document addresses, but is not restricted to, various suggested test piece fabrication methods. It applies primarily to ceramic and/or glass matrix composite tubes with a continuous fibrous- reinforcement: unidirectional (1D filament winding and tape lay-up), bi-directional (2D braid and weave) and tri-directional (xD, with 2 < x < 3), subjected to an internal pressure. Values expressed in this document are in accordance with the International System of Units (SI).
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 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment: Micrometers for external measurements — Design and metrological characteristics
ISO 20507, Fine ceramics (advanced ceramics, advanced technical ceramics) — Vocabulary ASTM E2208-02, Standard Guide for Evaluating Non-Contacting Optical Strain Measurement Systems
3 Termsand definitions
For the purpose of this document, the terms and definitions given in ISO 20507 and the following 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/
4 Principle
A prepared tubular test specimen of specified dimensions is inserted into an appropriate test fixture assembly and subjected to monotonic loading via indirect internal pressure up to fracture. Uniform radial pressure is produced using hydraulic oil injection with a piston through an elastomeric bladder located inside the tubular test specimen. The elastomeric bladder mates to the inner diameter of the tubular test specimen, thus causing its expansion under pressure. The test is performed at constant piston displacement or constant strain (or constant loading rate). Both the applied pressure and resulting hoop tensile strain are measured and recorded simultaneously. The hoop tensile strength and corresponding strain are determined from the burst pressure while the various other hoop tensile properties are determined from the stress-strain response data. Generally, the test is carried out under conditions of ambient temperature and environment. NOTE 1 The resulting force from internal pressure loading is applied in the radial direction. Monotonic refers to a continuous non-stop test rate with no reversals from test initiation to final fracture. NOTE 2 The method described in this document does not cover the possibility of applying pressurization via a dense rubber material in compressive without fluid.
ISO 21971:2019 pdf download
