shear modulus and damping ratio are important input parameters in dynamic analysis. a series of resonant column tests was carried out on pure clays and sand-clay mixtures prepared at different densities to investigate the effects of aggregate content, confining stress, void ratio and clay plasticity on the maximum shear modulus and minimum damping ratio. test results revealed an increase in the...

blown bitumen (110/10) was mixed with heavy vacuum slops (h.v.s), 60/70 penetration grade bitumen and recycled isotactic polypropylene (ipp) at different levels. the resulting resins were used to impregnate non-woven poly(ethylene terephthalate) fibers to form composites. the modulus and penetration grade of the resulting bituminous resins were determined. it was found that these bituminous res...

In the presented work, a non linear effect of rubber referred as Fletcher-Gent effect or Payne effect is investigated. It leads to a change in the rubber dynamic modulus with vibration amplitudes and, consequently, modifies resonance frequencies of mechanical systems including non linear elastomers. In this study a new methodology is developed to take into account Payne effect in a linear visco...

A new three-dimensional unit cell model has been developed for modeling three constituent phases including inclusion, interphase and matrix. The total elastic modulus of nano-composite is evaluated.  Numerical results are in good agreement with the previous proposed theoretical modeling. Higher matrix and inclusion elastic modulus both can dramatically influence the total elastic modulus.

handling of endodontic sealers is greatly dependent on their elasticity and flow ability. we compared the viscoelastic properties of three root canal sealers.ah plus (dentsply, de trey, konstanz, germany), endofill (dentsply hero, petrópolis, rio de janeiro, brazil) and ah26 (dentsply, de trey, konstanz, germany) were mixed according to the manufacturers' instructions. the resulted pastes were ...

The aim of this study is to theoretically investigate the effects design parameters on static equivalent stress radial rolling bearings, such as point contact case for ball bearings and line roller bearings. pressure, area von Misses are calculated based geometrical parameters, material loading by using developed MATLAB program. To achieve aim, both maximum pressure pmax Von Mises effective σVM...

In this research, the influence of adding micro- and nano- sized calcium carbonate powders to nylon-66 was investigated. Mechanical properties of micro and nano- composites, including tensile strength, elongation, and Young’s modulus, before and after ageing, were determined and analyzed. For this purpose, micro- and nano-sized CaCO3 particles were used as fillers to prepare micro-composites (c...