A mechanical test for remanent creep life.

Completed

Not Energy Related
Other Power and Storage Technologies(Electric power conversion)

Basic and strategic applied research

ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Dr M Evans
Engineering
Swansea University

Standard

EPSRC

01 December 2003

30 November 2006

36 months

£174,102

Materials sciences

Wales

Metals Programme -- Materials, Mechanical and Medical Eng

Dr M Evans, Engineering, Swansea University

Professor R Evans, Engineering, Swansea University

Project Contact, National Physical Laboratory (NPL)
Project Contact, Institute for Energy and Transport (IET), Joint Research Centre (JRC), Petten, The Netherlands
Project Contact, GenExP Limited
Project Contact, RWE Innogy
Project Contact, Johns Hopkins University, USA

The estimation of remanent life for high temperature plant is best performed through post exposure creep testing. Conventional creep specimens are large and their removal from components often destroys their useful service life. The small disc creep test eliminates this difficulty but the interpretation of the test results is difficult and at present entirely empirical. This research will properly characterise the mechanics of the disc creep test so that quantitative estimates of remanent lifecan be made. It will build a finite element model of the test, which will be verified using existing in house disc creep tests on virgin and creep damaged rotor steels. The model will be elastic-viscoplastic and will incorporate real creep properties obtained from the IRC (Swansea) data bank. A critical part of the model will be the inclusion of work hardening, thermal softening and Kachanov type damage accumulation. The accumulation rates will incorporate the effects of general three dimensional stress states.The model will then be used optimise the test conditions (geometry, surface conditions etc.) so that the test has the maximum sensitivity to pre-imposed levels of damage. The optimisation will be through Response Surface Methodology. The work will include an analysis of variability so that the effects of scatter can be estimated. The overall research will produce a auide to aood practice disc creep testing and will provide a quantitative methodology for remanent life estimation

01/01/07