Research on Mechanical Performance Parameter of Metal Rubber
Metal Rubber is special materials and used in aerospace, especially under extreme conditions. It has characteristics of strong adaptability, corrosion resistance, radiation resistance and designability. In this paper, we have manufactured Metal Rubber components, and done some research on the influence of previous deformation to Metal Rubber material's structure and performance, its characteristic parameters such as Poisson's ratio, Elastic modulus were studied. Research results are basic but essential for finite element analysis of Metal Rubber materials; these results also play an important role of engineering application.
Calculation of elastic damping characteristics of rotor support made of metal rubber material under variable loads
A metal rubber(MR) dry friction damper was designed based on the load supported by the rotor.An experimental apparatus for obtaining hysteresis loops of support under the precession load was designed.The elastic-damping characteristics of the ring-shaped MR damper used as a rotor support under variable loads were presented by studying the hysteresis loops of the damper.The vibration rigidity and the energy dissipation coefficient were calculated from the hysteresis loops, based on the description of the deformation process of the MR element with simple structure in a dimensionless coordinating system.The calculation results showed that the energy dissipation coefficient in the inner of MR element and on the boundary between the damper and the frame of the rotor support were approximately equal.The comparison of the hysteresis loops for a precession load and a one-axial load indicated a large difference when the coefficient of the energy dissipation and the stiffness of the MR damper were concerned.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.