Degree Type


Date of Award


Degree Name

Master of Science


Industrial and Manufacturing Systems Engineering


Industrial and Manufacturing Systems Engineering

First Advisor

Matthew Frank


This thesis presents an algorithm to automatically select the positions for friction stir spot welding (FSSW) in a laminated rapid tooling process. The work combines a two-dimensional structural analysis with tool path planning to realize the overall process planning for the rapid tooling of a plastic injection mold. The work starts from a two-dimensional cantilever beam model, defining the effective distance of a single spot joint strength, and also considers the effect of a single layer thickness. Secondly, an efficient medial axis transformation algorithm, which is suitable for the general two-dimensional boundary curves, has been proposed to generate the adaptive equidistance offsetting curves. In addition, through different working conditions of the internal and external spot welds, an adaptive discretization method is presented. Then, a selection principle for choosing the initial spot weld location and processing order with optimization to avoid redundancy is presented. Finally, the authors compare the advantages of this novel algorithm and traditional path planning algorithms with respect to strength and processing efficiency while taking into account structural strength.

Copyright Owner

Ziyang He



File Format


File Size

75 pages