TITLE:
Identification of Modal Loss Factor of a Sandwich Composite Structure with Polyethylene Terephthalate Core in the Aspect of Core Properties Determination
AUTHORS:
Krzysztof Marynowski, Katarzyna Grochowska
KEYWORDS:
Composite Material, Rheological Fractional Model, Viscoelasticity, Loss Factor, Shear Modulus
JOURNAL NAME:
Materials Sciences and Applications,
Vol.6 No.6,
June
4,
2015
ABSTRACT: Comparison of the loss factor determination methods of the sandwich composite structure with
polyethylene terephthalate core in the aspect of core material rheological parameters identification
was the purpose of the study. Three frequency bandwidths n dB: 1 dB, 2 dB, 3 dB methods,
the resonant amplitude method and the fit method of the response of the one degree of freedom
model system are taken into considerations. Identification procedure, according to ASTM E756-2005 [1] based on experimental studies of the forced vibrations of the composite structure was
presented in the paper. To determine the function of the complex shear modulus of the core
material, the Nelder-Mead method is applied. Shear modulus and loss factor identification results
were presented on the plots in the frequency domain. The results in a quantitative manner set the
applied methods and their practical utility in order.