Investigation of dynamic behaviour of laminated composite plates under cyclic loading
Andrzej Katunin, Marek Fidali
Quarterly No. 3, 2011 pages 208-213
DOI:
keywords: polymeric laminated composites, dynamic response, hysteresis, dynamic moduli
abstract Polymeric laminated composites show great potential in many engineering applications, especially in the aircraft industry, owing to their specific strength properties. Many machine components made of polymeric laminates are subjected to intensive vibrations. According to the viscoelastic nature of such composites, some specific effects e.g. energy dissipation could be observed during cyclic vibrations. Therefore, it is necessary to understand this behaviour and to develop appropriate methods and models for diagnostics and monitoring purposes. In this work the authors present the results of an experimental investigation into the vibration response of cyclically loaded glass-fiber reinforced polymeric (GFRP) rectangular plates. Initially, the frequency response functions (FRF) for the investigated specimens of various lengths were obtained during laboratory experiments. The natural frequencies of the specimens were determined based on their FRF. Then, the specimens were loaded on the first three natural frequencies to obtain characteristics showing the phenomenon of energy dissipation. Dynamic testing was carried out using a laser vibrometer and a piezoelectric force sensor. The evolution of the dynamic moduli was investigated based upon the measurement results, allowing estimation of the empirical model of material energy loss, necessary in building and testing the analytical model of the self-heating properties of the specimen material. The influence of an excitation frequency and the length of the specimens on their dynamic behaviour was additionally studied. The results of the conducted research could be successfully applied in diagnostics and structure health monitoring (SHM) applications and could be used to develop fatigue and fracture models of viscoelastic GFRP laminated composites.