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

Abstract

A numerical model based on the 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 thermoelastic contraction differences of fused silica with different fictive temperatures from initial frozen-in temperatures to the ambient temperature, and the residual stress fields of mitigated damage sites for the CO2 laser annealing 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 measurement. These results provide sufficient evidence to demonstrate the availability of the proposed model in describing the residual stresses of mitigated fused silica damage sites for the CO2 laser annealing case.