A computerized data acquisition system for fatigue crack growth studies in polymers

A new method for automatic fatigue crack measurement in polymers using electrical conductive surface grids and a micro-computer is developed. The grid pattern is made from a graphite ink and transferred to the specimen surface using a screen printing technique. The computer scans each bar individually and counts the elapsed fatique cycles using a simple interface. Experimental results for crack length and elapsed cycles are produced in a form suitable for further computer analysis to establish the Paris power law for fatigue crack growth. The usefulness and accuracy of this computerized automatic method are compared to the conventional optical method.