Numerical welding simulation

Magistrsko delo predstavlja numerično simulacijo varjenja. Varjenje je spajanje kovinskih ali nekovinskih delov s postopki dodajanja materiala. Proces varjenja je v programskem paketu Abaqus/CAE obravnavan kot nevezana toplotno – mehanska analiza z ločenim izračunom temperaturnega in napetostnega polja. Gibajoči toplotni varilni vir je modeliran na način definiranja začetne temperaturne porazdelitve v zvarni kopeli. Zaradi kompleksnosti fizikalnega dogajanja v zvarni kopeli je potrebno določene fizikalne procese zanemariti. Temeljno oviro pri numeričnem modeliranju varjenja predstavlja pridobitev ustreznih toplotnih in mehanskih lastnosti materiala v odvisnosti od temperature. Iz tega razloga so enaki podatki uporabljeni za osnovni in dodajni material. Analiza prenosa toplote je obravnava kot časovno odvisen problem in je uporabljena za izračun zaostalih varilnih napetosti pri napetostno – deformacijski analizi.The master’s thesis presents numerical welding simulation. Welding is a fabrication process that joins metal or non-metal materials, by adding molten filler material to base material. Welding process is modelled in Abaqus/CAE software as uncoupled thermo – mechanical analysis with separated calculation of thermal and stress field. The approach of defining the initial temperature distribution in weld pool is used to model moving heat source. It is necessary to simplify and neglect some physical processes in welding pool in order to decrease the level of complexity. The main problem by welding simulations is to obtain a temperature dependent characteristic material data. For that reason the same data were used for filler and base material. Transient heat transfer analysis was imported in structural analysis to calculate residual stresses