Reviews of Previous FESI Seminars and Workshops:

 

FESI and ESIS TC12
Meeting Using Probability Modelling in Structural Integrity Assessments
Chaired by Professor Peter Flewitt, Bristol University and British Nuclear Group
Date: 9th June 2006
Venue: The Royal Academy of Engineering, London, Great Peter St SW1P 3LW

 

Purpose

All major industry sectors are faced with the safe running and economic management of the lifetime of their plant, including machines, structures and components; from design and manufacture, through operation to retirement and decommissioning. As a result, common engineering structural integrity technologies are emerging across industry.

The purpose of this seminar is to review and discuss the use of statistical methods for the interpretation of materials property, data design of experiments and the use probabilistic methods in structural integrity assessments.

Seminar Review

The ESIS Technical Committee TC12 is concerned with application of probability and statistical modelling to structural integrity assessments in general, and material property data in particular. In order to pursue these objectives TC12 actively seeks collaboration with other Technical Committees within ESIS. To progress the TC12 activities a one day workshop was organised by TC12 in conjunction with the UK Forum for Engineering Structural Integrity (FESI). The latter is the ESIS national group for the UK. The meeting was held in central London at the Royal Academy of Engineering.

The workshop opened with a welcome to the 30 delegates pointing out that, in addition to the informed presentations and discussions, it was hoped to identify future topics for inclusion in the forward programme for TC12. A short introduction was given by Professor Peter Flewitt, chairman for the day, setting the background to this important area of probabilistic assessments for both the industrial and business communities across many sectors of transport, power generation, petrochemical, civil structures and aerospace.

A wide range of high quality presentations followed covering modelling of fracture toughness by different statistical techniques which include both the Master Curve approach and statistical analysis. In addition to these, presentations were given on modelling of creep crack growth, fatigue crack growth, evolution of pitting in stress corrosion cracking and use of partial safety factors in fracture mechanics. Each presentation was followed by a lively discussion highlighting the many challenges that remain to achieve broad acceptance and application of probabilistically based structural integrity assessments for structures and components. In the course of the concluding discussion it was recognised that future topics to address would cover the use of computer simulations in modelling and application of probabilistic methods.

Programme

Session 1

Kim Wallin, Finnish Academy, VTT Materials Performance, Finland:
Statistical Aspects of the Master Curve to Consider in Structural Integrity Assessment

John S Kent and J D G Sumpter, QinetiQ:
Characterising Scatter in Ship Plate Fracture Toughness

Robert Moskovic, British Nuclear Group, R A Ainsworth, British Energy:
Estimation of Lower Bound Engineering Fracture Toughness in The Ductile to Brittle Transition Temperature Region.

Kamran Nikbin, K Wasmer and G A Webster, Imperial College:
Sensitivity Analysis Using Monte Carlo Simulations on Creep/Fatigue Crack Growth.

Session 2

Amin Muhammed, TWI:
Partial Safety Factors in Fracture Mechanics Assessments

Michele Carboni, S Beretta, Politecnico di Milano, Italy:
Stochastic Description Fatigue Crack Growth Including Near Threshold Regime

Thomas Svensson, Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Sweden:
An Uncertainty Weighted Safety Factor for Fatigue dDsign

Alan Turnbull, NPL:
Statistical Considerations in Predicting the Evolution of Pitting and Stress Corrosion Cracking

TC12 will be making a significant contribution to the forthcoming European Conference on Fracture to be held in Greece at the beginning of July. It is planned to hold a meeting of TC12 during ECF16 so that the way forward for this group is agreed. If you are attending ECF16, a notice will be posted giving the time and venue for the meeting. Please come along.

Robert Moskovic

Chairman TC12
June 2006