Patent ID: 8519337

Claim:
A method of determining a physical property of a composite material, comprising: providing at least one of a composite material and a surfacing film standard; irradiating said standard with near-infrared energy; detecting near-infrared energy reflected from said standard; performing pre-processing on infrared spectra from said standard with a plurality of pre-processing methods; performing multivariate analysis on a spectrum of said near-infrared energy reflected from said standard; subjecting said standard to mechanical tests to obtain a residual strength of said standard; obtaining a correlation of a spectrum of near-infrared energy reflected from said standard; quantifying a degree of thermal effect to said standard by comparing results of said multivariate analysis with said correlation; predicting thermal exposure or mechanical properties of a material in question based on said degree of thermal effect; calculating root mean square error of prediction for each of said plurality of pre-processing methods; and selecting from said plurality of pre-processing methods a pre-processing method having a lowest prediction error for future use.