INBJUDAN TILL SEMINARIUM I HÅLLFASTHETSLÄRA Civ. ing Erik Lundström presenterar sin licentiatavhandling i ämnet Hållfasthetslära. Seminariet hålls på engelska. Modelling of fatigue crack propagation in Inconel 718 under hold time conditions Fredag den 21 mars 2014 kl 10:15 Plats: Linköpings universitet, Campus Valla, Hus A, Ingång 17, plan 3, föreläsningssal A34 (karta till föreläsningssalen finns på baksidan av detta blad) In this thesis an investigation and modelling of fatigue crack propagation in the nickel based superalloy Inconel 718, with a special emphasis on the effect of hold times, is presented. The modelling work has been concentrated on describing the hold time fatigue crack propagation by using the concept of a damaged zone in front of the crack tip, which is believed to have a lowered resistance against crack propagation. The modelling framework is built on physically motivated parameters, which are all easy to calibrate through one specially designed test type. Later evaluation through many experimental tests has also shown that the model is capable, within reasonable scatter level, to predict the hold time fatigue crack propagation for many different temperatures and loading conditions. Further, evaluation of a complex flight spectrum, with the incorporation of crack closure within the model, was also carried out with a satisfying result. This thesis is divided into two parts. First, a background and a somewhat deeper discussion of the modelling of fatigue crack growth under hold time conditions is presented. The second part consists of five appended papers, which describe the work completed so far in the project. VÄLKOMNA IEI-salar
LOKE-salar
AG31 AG32 AG33AG34 AG35
A31
A32
A30
DELTA
A301
A1
A33
ISLA
(Island)
A34
A35
A2
NOBE
Studentkök
Hus A plan 3
AG36
A36
A37
A38
IPLA
A39