STONE IMPACT DAMAGE TO AUTOMOTIVE PAINT FINISHES - A STATISTICAL AND NEURAL-NET ANALYSIS OF ELECTROCHEMICAL IMPEDANCE DATA

Automotive car bodies are subject to impact by stones either lofted fr om tires or launched by other passing vehicles. Impact can result eith er in physical loss of paint or the possibility of failure at the meta l/phosphate-polymer interface. Corrosion brought about as a result of impact is referred to as Impact Induced Corrosion or IIC. Electrochemi cal impedance is very sensitive to delamination at the metal-polymer i nterface and is able to discern the influence of velocity, angle of im pact, the type of coating and ambient temperature on stone impact dama ge. Application of both statistical and Artificial Neural Network (ANN ) analysis are presented.