Characterization of Optical and Surface Parameters During Particle Impact Damage

The damage caused by sand impingement can be severe and detrimental to canopies, radomes, wind screens, and structural components resulting in loss of transmittance, communications, and premature failure. Extensive parametric studies were conducted to characterize the optical transmittance characteristics of polymethyl methacrylate and polycarbonate surfaces as functions of (1) velocity of impact, (2) exposure time (3) distance of the nozzle (4) angle of impingement, and (5) mass flow rate of the erodent. Particle damage was caused by a jet of high speed spherical and (crushed glass and silicon carbide) angular particles. The relationship between the optical and surface characteristics are discussed.