This paper summarizes the results of a recent investigation on the dynamic response of asymmetric-plan buildings with supplemental viscous damping to harmonic ground motion using modal analysis techniques. It is shown that most modal parameters, except modal damping ratios and dynamic amplification factors, are affected very little by the plan-wise distribution of supplemental damping in the pr...

The effects of amine functionalization of carbon nanotubes (CNTs) and CNTs weight percent (wt. %), on the first bending natural frequencies and damping properties of CNT/epoxy composites are investigated in this paper. CNTs and amine functionalized CNTs (AFCNTs), with two different weight percentages, are used to manufacture the beam shaped specimens. Epoxy, CNT/epoxy (0.25 and 0.5 wt. % of CNT...

Measurements of the roll-damping derivative (lp) of three wing planforms were made by the free-flight roll-balance technique over the Mach number range 0-7 to 1.4. The wings were all of RAE 102 section, 7" 5 per cent t/c and aspect ratio 2.83 but varied in sweep and taper ratio. The two wings of taper ratio 0.33 showed little loss of damping in the transonic region but the 50 deg delta wing suf...

in this work the general aspect and the behavior of a simplified theoretical model for studying mass isolated systems are investigated. the model is in the form of a dual mass model in a single storey arrangement. to find damping ratio and natural frequency of the system, non-classical eigen analysis has been performed on the model. later, time integration analyses subjected to different earthq...

The vibration serviceability of flooring structures has been of concern for decades. To date, design criteria classifying the dynamic behaviour of different types of timber flooring structures to an acceptable degree have not been well established. Parameters commonly used to investigate and assess vibrational performances of timber floors include natural frequencies, damping ratios, dynamic di...

in this paper, a novel compensator based on magnetically controlled reactor with fixed capacitor banks (fc-mcr) is introduced and then power system stability in presence of this compensator is studied using an intelligent control method. the problem of robust fc-mcr-based damping controller design is formulated as a multi-objective optimization problem. the multi-objective problem is concocted ...

Numerical example shows that when the damping ratio of the isolation device is given, the overall reliability of the structure increases at first then decreases with increased frequency ratio, when the frequency ratio is constant, the overall reliability of the structure increases with increased damping ratio. In addition, compared to the aseismic system, the overall reliability of the mega-sub...

This paper presents a new kind of shock absorber, hydraulic electromagnetic energy-regenerative shock absorber (HESA), which can recover energy from vibration of vehicles. The road excitation frequency, load resistance and damping ratio are found to greatly affect the energy recovery of HESA. Based on a quarter-car model, the optimal load resistance and damping ratio for maximizing the energy-r...