The objective of this work was to develop a phenomenological model of pulsed CO 2 laser interaction with reinforced composite materials. Experimental observation has shown that the multilayer composite material delaminates under pulsed CO 2 laser irradiation. This is a consequence of the energy storage mechanism arising out of a finite absorption depth to the laser radiation. A heat transfer model was developed to describe the observed delamination behavior of the composite materials. Good agreement was obtained between the model predictions ami experimental data. The model has been used to extrapolate to high average power irradiation.
Nomenclaturec -specific heat E R = residual fluence E R() = residual fluence for surface at ambient temperature E v = heat of varporization h = laminate thickness R = pulse repetition frequency t = time T = absolute temperature T 0 = ambient temperature x = distance from target surface a. -thermal diffusivity A = laminate displacement Aw = velocity differential across laminate Ap = differential pressure d = constant in Eq. (5) p = material density X = conduction depth X a = absorption depth for laser radiation 8 = temperature, = T-T 0 r -shear stress in laminate li = glass viscosity i] = heat transfer parameter, = x/ (2^fai) £ = heat transfer parameter, =E RQ R/[pcaQ v ] f = mass removal parameter in Eq. (19) o) = Vctf/X Subscripts D = delamination V = vaporization R = removal