Calibration and traceability of notch creep strain measurements

Abstract

Blunt circumferential (Bridgman) notched tensile creep testpieces are used for determining material property data under a multi-axial stress state at high temperatures. Aspects of calibration and traceability for diametral strain measurement are considered, with particular reference to creep strain measurement on Bridgman notched testpieces. Details are given of a new laser interferometer calibrator rig used to provide traceability to the National Measurement system for diametral and axial extensometers used for notch creep strain measurement.

Keywords:

• calibration
• diametral extensometer
• creep strain measurement
• Bridgman notches
• triaxial stress state
• standards
• laser interferometer