Damage mechanism of High Frequency Mechanical Impact (HFMI) Treated Welded Structures under Service Loading to Increase the Fatigue Life for Lightweight Design

Información del proyecto

Hi-Life

Identificador del acuerdo de subvención: 702233

DOI

10.3030/702233

Proyecto finalizado el 31 Diciembre 2018

Fecha de la firma de la CE 17 Marzo 2016

Fecha de inicio 1 Septiembre 2017

Fecha de finalización 31 Agosto 2019

Financiado con arreglo a

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Coste total

€ 175 419,60

Aportación de la UE

€ 175 419,60

Coordinado por

ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Switzerland

Objetivo

The use of high-strength steel (HSS) grades leads to significant weight reduction and increased service life, especially in complex-welded structures. However, their implementation is limited in practice due to the fatigue issues at welds, welds which have the same fatigue life as those in lower strength steels. High-frequency mechanical impact (HFMI) treatment allows for important fatigue life improvement based on the induced compressive residual stress (RS), improved weld shape and cold-worked surface region. In current drafted guidelines, these factors were derived according to the weld toe failures obtained under constant amplitude loading (CAL) and also verified by a limited dataset under variable amplitude loading (VAL), the latter being more realistic of service loadings. Current knowledge on HFMI-improved welds has also shown that fatigue failures may also initiate at other regions, rather than weld toe. In spite of the fact that relaxation of induced RS state has been claimed to be the main reason of different damage mechanisms resulting in the failure location change, scientific questions such as: why, how and under what conditions this effect occurs or what damage mechanisms play a dominant role, remain unanswered. Based on the above context, the objective of this proposed project aims to solve the damage mechanisms of HFMI-treated welds under service loading by considering fatigue tests, investigating the microstructures and developing analytical approaches. The proposed scientific approach includes investigations on the development of grain structure size/orientation through the depth of HFMI groove by neutron scattering, and on the relation of grain-orientation-dependent RS state under service loading. This training will also allow transferring of the obtained knowledge obtained to the industrial partner for the implementation of this novel treatment technique by utilizing HSS in the shipyard.

Ámbito científico (EuroSciVoc)

• ciencias agrícolas › agricultura, silvicultura y pesca › agricultura › granos y semillas oleoaginosas
• ingeniería y tecnología › ingeniería civil

Palabras clave

• Fatigue strength improvement
• high-frequency mechanical impact treatment
• high-strength steel
• damage mechanism
• lightweight design

Programa(s)

• H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions PROGRAMA PRINCIPAL
  
• H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility
  

Tema(s)

• MSCA-IF-2015-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF)
  

Régimen de financiación

MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)

Convocatoria de propuestas

H2020-MSCA-IF-2015

Coordinador

ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE

• Aportación neta de la UEn: € 175 419,60
• Dirección: BATIMENT CE 3316 STATION 1 ; 1015 LAUSANNE ; Suiza
• Región: Schweiz/Suisse/Svizzera › Région lémanique › Vaud
• Tipo de actividad: Higher or Secondary Education Establishments
• Coste total: € 175 419,60