Laser cutting of Kevlar laminates and thermal stress formed at cutting sections

Laser cutting of Kevlar laminates is carried out and thermal stress field developed in the cutting region is predicted using the finite element code. Temperature predictions are validated through the thermocouple data. The morphological changes in the cutting section are examined by incorporating optical and scanning electron microscopes. It is found that temperature predictions agree well with the thermocouple data. High values of von Mises stress are observed at the cutting edges and at the mid-thickness of the Kevlar laminate due to thermal compression formed in this region. The laser cut edges are free from whiskers; however, striation formation and some small sideways burning is observed at the kerf edges.

► Parallel sided cut edges are formed; however, shallow striation patterns are observed.
► Small sideways burning results due to high temperature combustion at the cut sections.
► Surface temperature predicted agrees well with the thermocouple data.
► von Mises stress reaches its maximum in the neighborhood of cut edges.