Peak stress reduction in the laser contouring of CFRP

At the outer edge of highly stressed CFRP parts, critical stress peaks arise at notches. In fatigue testing of tensile specimens with a centred circular notch, an unpredictable fibre based breakage was observed for specimens manufactured by abrasive waterjet cutting. Using a remote laser cutting process changed the failure mode to well predictable matrix based. The finite element simulation shows that the peak stress on the loaded fibres within the heat affected zone was reduced to a noncritical value based on the elimination of the material's shear force capacity. Consequently, laser cutting demonstrates significant potential for lightweight construction with CFRP.