부산대학교 도서관

In this work, a transient three-dimensional finite element model (FEM) of the laser micro spot welding (LMSW) process was established considering three heat source approaches: static heat source model (SHSM), dynamic heat source model (DHSM), and double dynamic heat source model (DDHSM). Each model was computed according to the aspect ratio of spot width to depth and the absorptance of the material. The numerical simulation computed the conduction-to-keyhole transition using an AISI 302 stainless steel alloy. Our results showed that the DDHSM results were based on the experiments reported in the literature. The conduction-to-keyhole transition for the SHSM and DHSM was observed to depend on the average laser power, having a constant keyhole aperture at 75 ms exposure time and 220 W average laser power. Additionally, the DDHSM configuration gave a conduction-to-keyhole transition with a similar constant aperture at 75 and 50 ms of exposure time for 200 and 220 W average laser power, respectively. The percentage errors for the DDHSM were 8%, 15%, 17%, and 20% for the penetration depth, top, middle, and bottom width, respectively.