Session: CS-17-03 Environmental Fatigue Issues (Joint with M&F)-3: INCEFA SCALE & International Studies

Paper Number: 154809

154809 - Environmentally Assisted Fatigue Component Test Transient Benchmarking and Inspection Qualification 

Abstract: 

Environmentally Assisted Fatigue (EAF) correlations have been developed based predominantly on testing performed on small, simple specimens under mechanical loading and isothermal conditions.  EPRI is currently leading an effort to conduct testing on realistic components with plant-representative transients.  This work aims to assess whether using components and/or component-like features under plant-representative loading conditions will provide additional insights on the current EAF models for both fatigue crack initiation and propagation that have been developed from small-scale specimens tested under mechanical loading conditions. A test loop was designed in 2018 to subject a multiple-stepped pipe to thermal strains generated by changing fluid flow conditions.  The planned test transients were thermal shocks, moderate ramp rates, and slow ramp rates.  After a series of delays, in 2023 the project was restarted and the test loop commissioning activities began.  This paper details the results of thermal and strain benchmarking, along with non-destructive examination (NDE) qualification efforts.  Test specimens fitted with a series of strain gauges, thermocouples, and through-wall temperature sensors were subjected to the various test transients.  The data were used to assess the original design calculations and test duration predictions and refine them for the upcoming prototype testing that will be performed in the next phase of this effort.  Additionally, the NDE procedures were evaluated and sized through a separate qualification test aimed at determining the sensitivity of the equipment that will be used to identify the onset of fatigue crack initiation and track fatigue crack propagation from the initiated flaws.   

Presenting Author: Thomas Damiani EPRI

Presenting Author Biography: Dr. Thomas M. (Tom) Damiani is a Principal Technical Leader within the Materials Reliability Program (MRP) at the Electric Power Research Institute (EPRI). Dr. Damiani’s research focus within MRP will be related to structural fatigue analysis and the impact of Light Water Reactor (LWR) environments on both the fatigue and fracture characteristics of primary pressure boundary and related internal materials.

Prior to joining EPRI in December 2021, Dr. Damiani was the Manager of Structural Methods Development and Implementation at the Naval Nuclear Laboratory (NNL). Serving in this position for six years, he was NNL’s cognizant manager for the Naval Structural Design Basis document SDB-63 and the affiliated software that implements the design and continued use procedures for the U.S. Naval Nuclear fleet.

Previously, Dr. Damiani worked within the Structural Methods and Analysis Development unit at NNL for ten years. Research focuses during this time included Finite Element (FE) based fatigue analysis and explicit flaw crack growth methods. Dr. Damiani received his BS degree in Engineering Physics from West Virginia Wesleyan College, and a MS and Ph.D. in Mechanical Engineering from West Virginia University.

Dr. Damiani is a member of the ASME Boiler and Pressure Vessel Code Committee’s Working Group on Fatigue Strength and Environmental Fatigue Evaluation Methods within Section III.

Authors:

Thomas Damiani EPRI
Andrew Morley Rolls-Royce Submarines Limited
Sam Cuvilliez EDF