Measurement of Dynamic Properties of Composites in Vibration by Means of a Non-contact Mechanism

When dynamic properties of structures in vibration are considered, their elastic modulus and damping properties are emphasized. One of the best ways for true measurement of damping is the use of a beam with free—free end conditions. The aim of this study is to investigate dynamic properties of composites by using the vibrating beam technique. The composite specimens with free—free end conditions were vibrated at their fundamental nodes. An electro-magnetic shaker was used to vibrate the specimens by means of air flow and their responses were taken by means of a microphone, a non-contact mechanism. It has been shown that this technique produces accurate and repeatable results and that this is a reliable method for the dynamic measurements.