GB/T 46444-2025Test method for tension-tension fatigue properties of carbon fibre reinforced ceramic matrix composites at elevated temperature (English PDF)

1 Scope

This document specifies the tensile-tensile fatigue life curves and conditional fatigue limit tests for carbon fiber reinforced ceramic matrix composites under high-temperature conditions.

The principle of the test method, instruments and materials, test specimens, test conditions, test procedures, result calculation and test report.

This document applies to the determination of tensile fatigue strength of ceramic matrix composites reinforced with continuous carbon fibers in a high-temperature environment of 600°C to 1650°C.

The SN curves and fatigue limits under fatigue loads are used as a reference for continuous silicon carbide fiber reinforced ceramic matrix composites.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 1446 General Rules for Test Methods of Properties of Fiber Reinforced Plastics

GB/T 2611 General Technical Requirements for Testing Machines

GB/T 12160 Calibration of extensometer systems for uniaxial testing of metallic materials

GB/T 16825.1 Inspection and calibration of static uniaxial testing machines for metallic materials - Part 1.Tensile and/or compressive testing machines

Inspection and calibration of force measurement system

GB/T 16839.1 Thermocouples - Part 1.Electromotive Force Specifications and Tolerances

GB/T 40724 Terminology for Carbon Fibers and Their Composites

3 Terms and Definitions

The terms and definitions defined in GB/T 40724, as well as the following terms and definitions, apply to this document.

4 Principles

Under high-temperature conditions, at different tensile stress or strain levels, the specimen is subjected to constant stress or strain amplitude, stress ratio, and frequency.

Apply alternating stress or strain until the specimen fails or reaches the specified number of cycles. Analyze the test results and plot the stress life.

(SN) curves or strain-life (epsilon-N) curves are used to obtain the conditional fatigue limit. […]