Fatigue impact of residual stresses from manufacturing processes
Typ
Examensarbete för masterexamen
Program
Applied mechanics (MPAME), MSc
Publicerad
2022
Författare
Tegnemyr, Klas
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This study was done to investigate how residual stress from different manufacturing
processes could be simulated and what effect they would have on predicted fatigue
life of the components.
The two manufacturing processes investigated were forming and welding. The forming
process was simulated through a two-simulation process, an explicit forming
simulation and an implicit springback simulation were used to evaluate the residual
stress formation. There were results from the forming simulation that need further
investigations to ensure trustworthy results. The welding process featured a simplified
simulation divided into two parts, a heat transfer simulation and an implicit
static simulation.
Results from the forming simulation gave similar stress levels as the measured values.
The welding simulation did not give as good results as the forming simulation.
A different method should be investigated to get more accurate results.
Residual stresses impact on the predicted fatigue life was examined by comparing
a component safety factor to fatigue with and without residual stress added to the
simulation. The result showed that the safety factor decreased moderately when
accounting for the residual stresses due to the elevated mean stress.
This master thesis was done on behalf of Azelio in collaboration with Uniso Technologies.
Azelio develops a thermal energy storage called TES.POD that uses stored
thermal energy to provide energy through a Stirling engine. The system has a storage
capacity of 13 hours that could work as an off-grid solar system storage.
Beskrivning
Ämne/nyckelord
residual stress , simulation , forming , welding , fatigue