LASER EFFECTS ON THE DYNAMIC-RESPONSE OF LAMINATED COMPOSITES

Transient response of a moving composite laminate suddenly subjected t o combined mechanical load and high intensity laser irradiation was in vestigated. The three thermal effects, which are caused by rapid laser heating and influence the structure's dynamic behavior, are material property degradation, burn-out and induced thermal loading. To determi ne temperature distribution and material burn-out due to the high lase r energy deposition, a modified Crank-Nicholson finite difference sche me, which includes the effects of surface ablation, degradation of the rmophysical properties at elevated temperatures and heat losses from r adiation and convection, was employed. The predicted thermal results w ere then used for thermal loading calculation and, subsequently, force d vibration analysis. Both small and large deflection composite plate theories were adopted. The inclusion of temperature-dependent mechanic al properties in the analysis was also of particular importance. It wa s shown that the escalation or reduction of vibration response of a la minated composite subjected to transverse loads by laser irradiation d epends not only upon the laser intensity, but also, which plate surfac e is irradiated. It was also found that a higher power laser irradiati on ensures neither greater escalation nor reduction of the vibration.