non destructive evaluation of glass-epoxy composite using impact-echo method

in this paper a new method for nondestructive testing or nondestructive evaluation is proposed for glass-epoxy composite. for this purpose, impact-echo is used to evaluate the properties of composite materials, detecting internal defects and thickness measurement. in the impact-echo method a steel ball impacts on a composite plate and generates stress waves or p-waves which will be transferred into the plate. the results show that impact response of the composite plate for dominant thickness frequency for measuring thickness and locating the defect is in agreement with the normal measurement. results represent that this method could be used for thickness measurement and flaw detection of epoxy-glass composites with a reasonable accuracy.