TWO MOIRE METHODS USED TO MEASURE STRAIN DISTRIBUTION OF COMPOSITE MATERIALS

Fundamental prineiples and practical procedures for experiment of the grating lines multiplication Moire method and the high sensitivity Moire interferometry are presented.Real time observation and recording of full displacement field of composite material specimen at various load levels can be made by using either of the methods. A comparison is made between the two methods to show their advantages and scope of their use. In addition,a resistance type strain gauge measurement is made on the same specimen in order to check the precision of the two methods.A good agreement is found between the measurement results obtained by using the Moire methods and those by strain gauges.