The　cutterhead　is　the　most　important　part　of　a　shield　tunneling　machine.　The　bracket　part　commonly　generates　cracks　on　the　surface　due　to　the　harsh　working　environment.　The　laser-generated　surface-acoustic-wave　(SAW)　detection　method　is　a　promising　non-destructive　method　for　detecting　such　cracks.　In　this　paper,　we　present　a　method　of　locating　the　defect　by　analyzing　the　interaction　between　laser-generated　SAWs　and　cracks　in　the　bracket　structure　with　the　finite　element　model.　Complicated　propagation　phenomena　are　observed　from　displacement　fields　at　different　times.　The　SAWs　interact　with　the　junction　first,　and　generate　transmission,　reflection,　and　mode-conversion　waves.　Then,　the　newly　generated　SAWs　interact　with　the　crack　and　undergo　the　same　phenomena.　Detailed　analysis　on　out-of-plane　displacement　waveforms　is　discussed　to　identify　the　wave　mode.　The　results　show　that　the　newly　generated　trtR　wave　in　the　out-of-plane　displacement　at　the　receiving　point　on　the　horizontal　plate　can　be　used　to　locate　a　crack　with　an　error　of　only　1.5%.　©　2022　SPIE.