Experimental and simulation investigation of temperature effects on modal characteristics of composite honeycomb structure

Modal analysis is the basis of the structural dynamics design and optimization. When operating in a thermal environment, the structure may be affected by the temperature in diverse aspects. In this paper, a sandwich structure composed of carbon fiber woven skins and a Nomex honeycomb core is taken as the research object. Temperature effects on its modal characteristics are investigated by experiments and simulations. During the test, natural frequencies and modal damping ratios of the specimen change with temperature dramatically, while each mode exhibits a particular trend. Although the temperature-dependent material property of the skin is identified as the essential factor of the variations in the modal parameters, the modulus components of the skin material have different sensitivities to the temperature change. As a result, correlations between the natural frequencies and modulus components are related to the corresponding mode shapes. And these correlations are studied by the finite element analysis.