الفهرس 
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Abstract
The importance of material damping in the design process has increased in recent
years as the control of noise and vibration in high precision, high performance
structures and machines has become more of a concern. The main objective of the
present work is to investigate the influence of some materials and test variables on
the viscoelastic behavior (Dynamic Mechanical Properties) of glass fiber reinforced
(GFR)/plastics composites. Material variables include: matrix type, off-axis angle
and fiber configuration. Variation of matrix (epoxy, vinylester and polyester) and
fiber configuration (unidirectional, woven and chopped) result in five different
composite materials. These composite laminates are unidirectional GFR/polyester
(UD-GFRP), unidirectional GFR/vinylester (UD-GFRV), unidirectional
GFR/epoxy (UD-GFRE), woven GFRP and chopped GFRP.
These composites are locally manufactured using hand lay-up technique. To
investigate the influence of fiber orientation on dynamic mechanical properties, the
unidirectional composite laminates with different matrices are cut at different offaxis
angles ( = 0°, 15°, 30°, 45°, 60° and 75°). Test variables include: temperature
and the frequency of the dynamic load. Longitudinal sinusoidal dynamic loads with
different loading frequencies (3.5, 11, 35 and 110 Hz) were implemented on the
composite materials under wide temperature range (25°C up to 130°C) using
Rheovibron DDV-III-C instrument. from experimental results the creep
compliances and relaxation moduli behaviors were predicted theoretically using an
Inverse Fourier Transform and numerical integration.