Laser heating of a moving slab: Influence pulse intensity parameter on temperature and stress fields

• von Mises stress behaves similar to temperature distribution along x and y-axes.
• Influence of laser intensity parameter is significant on stress levels.
• Gaussian distribution of laser pulse intensity results in large amplitude pulsation of von Mises stress.

Laser repetitive pulse heating of a moving slab is considered. Temperature and stress fields in the irradiated region are predicted for various laser pulse intensity distributions at the workpiece surface. The laser pulse intensity parameter is introduced to alter the intensity distribution at the workpiece while keeping the pulse energy constant for each distribution. An experiment is carried out to validate the predictions of surface temperature. It is found that surface temperature predictions agree well with the experimental data. Laser intensity distribution has significant effect on temperature and stress fields. In this case, Gaussian intensity distribution results in high values of von Mises stress in the irradiated region, which oscillates with the laser repetition rate. Altering the laser intensity through increasing the pulse intensity parameter (β) while keeping the pulse energy constant minimizes the effects of high cyclic thermal and stress loadings of the surface.