Experimental identification of non-stationary self-heating characteristics of laminated composite plates under resonant vibration
Andrzej Katunin, Marek Fidali
Quarterly No. 3, 2011 pages 214-219
DOI:
keywords: polymeric layered composites, resonant vibrations, self-heating temperature, infrared thermography
abstract This paper presents experimental studies on the thermal response of laminated composite plates under resonant vibrations. The thermoviscoelastic behaviour of laminated glass-fibre reinforced polymer (GFRP) composite specimens was studied. The specimens were subjected to purely flexural bending cyclic loading conditions on their three first bending resonant frequencies. During the examination of the specimens, frequency response functions (FRF) and thermal responses were evaluated. Infrared images acquired during the experiments also allowed the study of the temperature profiles of the specimens and temperature evolution over the loading time. The maximal magnitudes of temperature were observed at a point located on specimens’ clamp line, which was caused by the maximal stress magnitudes. The temperature evolution curves revealed the double-exponential characteristic which was affected by the evolution of the dynamic moduli of the material during resonant vibration. The temperature increased until the equilibrium between the dissipated energy and energy convected to the environment was reached. Based on the measurement data, the empirical model of self-heating temperature evolution was proposed. The influence of the excitation frequency and the plate length on the obtained temperature distributions was also examined. It was noticed that the excitation frequency was linearly dependent and the plate length was power dependent on the self-heating temperature, which confirms the numerical results obtained in previous theoretical studies. The obtained results could be used for the prediction and prevention of composite structural degradation during resonant cyclic constant-strain loading.