Residual stress modeling of mitigated fused silica damage sites with CO2 laser annealing

Abstract

A numerical model based on measured fictive temperature distributions is explored to evaluate the residual stress fields of CO2 laser-annealed mitigated fused silica damage sites. The proposed model extracts the residual strain from the differences in thermoelastic contraction of fused silica with different fictive temperatures from the initial frozen-in temperatures to ambient temperature. The residual stress fields of mitigated damage sites for the CO2 laser-annealed case are obtained by a finite element analysis of equilibrium equations and constitutive equations. The simulated results indicate that the proposed model can accurately evaluate the residual stress fields of laser-annealed mitigated damage sites with a complex thermal history. The calculated maximum hoop stress is in good agreement with the reported experimental result. The estimated optical retardance profiles from the calculated radial and hoop stress fields are consistent with the photoelastic measurements. These results provide sufficient evidence to demonstrate the suitability of the proposed model for describing the residual stresses of mitigated fused silica damage sites after CO2 laser annealing.