Abstract: The stir-casting method was utilized in this paper to synthesize 6063Al/Al2O3·SiO2
reinforced composites consisting of 6063Al alloy as matrix and Al2O3·SiO2 particles as additive with
content of 5%, 10%, 15%, 20% (volume fraction) respectively. Al2O3·SiO2 particles were obtained
from fly ash particles of Steam Power Plant and were pretreated. The shape of these fly ash particles
was spheroidal and ellipsoidal. The damping behavior of 6063Al/Al2O3·SiO2 particle reinforced
composites was studied by measuring the composite’s internal friction values on a Multifunctional
Damping Measurement Apparatus. Under the condition of this series of experiments,
6063Al/Al2O3·SiO2 particle reinforced composites had a higher internal friction values than that of
6063Al matrix and also showed the dependency of internal friction on Al2O3·SiO2 particles volume
fraction, particles dimension, vibration frequency and temperature. There was an increased trend for
internal friction values with increasing the volume fraction of Al2O3·SiO2 particles and decreasing
particles dimension of Al2O3·SiO2 at the same frequency and the different temperature. It has been
found that in the lower frequency, the higher internal friction value was obtained. The internal friction
of the composites increased with increasing temperature. In the case of lower frequency, two damping
peak were observed. A low-temperature damping peak appeared at a temperature near 245°C which a
high-temperature damping peak appeared near 450°C. Based on the experimental results, the
damping mechanism of 6063Al/Al2O3·SiO2 particle reinforced composites was preliminary
discussed. It may be concluded that the damping mechanisms associated with 6063Al/Al2O3·SiO2
reinforced composites include mainly intrinsic damping, dislocation damping and interface damping.
However, only the interface damping mechanism is dominant at high temperature.
Authors: Di Liu, Shu Lin Wang, Yan Chen Du, Hai Chao Li, Yin Zhang Sun
Abstract: In cantilever beam system, through the experimental method to study vibration reduction mechanism of particle collision damper. The filling rate of particle damping agent in damper is 40%, added the damper with different diameter impacters and different kinds of particle damping agent in combinations ways, the cantilever beam system obtained the varying vibration reduction, according to the quality of vibration reduction, analyzed the joined impacters and particle damping agent influence of vibration attenuation rule. Experimental results show that damper added impacters and particle damping agent can dramatically reduce the maximum amplitude of cantilever beam system in resonant frequency, and can effectively restrain vibration of cantilever beam system.
Abstract: The modal properties of carbon fiber woven fabric / epoxy resin composites with different fiber orientation angles were studied by using single input single output free vibration of cantilever beam hammering modal analysis method. With the same fiber volume fraction, the different fiber orientation of the laminated composite has an effect on parameters of vibration mode of composites. The experimental results show that with the fiber orientation increasing, the natural frequency of laminated composites becomes smaller and damping ratio becomes larger. The fiber orientation smaller, the peak value of natural frequency becomes higher and the attenuating degree of acceleration amplitude becomes slower.