Crack Modelling In Power Plant Components
R. Chandwani, C. Timbrell, M. Wiehahn
International Conference On Pressure Vessels And Piping, Chennai, India, Feb 7-9 2006
Abstract:
Much of the process plant designed in the early 1970s, in response to
increased demand for power, is now 'ageing' and necessitates an on-going
'fitness for service' assessment. This is necessary to satisfy
licensing authorities requirements for continuous operations. Fitness
for service assessment involves many issues including evaluation of
structural flaws, material degradation, damage due to creep, fatigue and
plasticity and the overall effect on the residual life of components.
Codes of practice such as API 579, BS 7910 and R6 give detailed
assessment procedures and may involve very detailed and time consuming
finite element analyses. The authors have developed an FEA tool,
Zencrack, to accurately evaluate single or multiple cracks in any
structure (e.g. pressure vessels, piping, etc.). Further, 3D non-planar
crack growth under general fatigue or time dependent loading is
possible. The software can help to increase efficiency in performing
sensitivity studies, thus allowing more accurate assessment of the
residual life of the plant than would otherwise be possible in a given
timeframe.