Accurate evaluation of damping ratios involving soilstructure interaction (SSI) effects is the prerequisite for seismic design of in-situ buildings. This study proposes a combined approach to identify damping ratios of SSI systems based on ambient excitation technique. The proposed approach is illustrated with main test process, sampling principle and algorithm steps through an engineering exam...

The damping capacity and mechanical properties of Mg-6Al-1Zn alloy after heat treatment were investigated. The damping characteristics of un-heat-treated, solution treated, and aged Mg-6Al-1Zn specimens were determined by measuring the damping ratio and the logarithmic decrement of free vibrations of a bending beam clamped at one side. The microstructural evaluations confirmed that the β-Mg17Al...

Sayed, Shehrin. M.S.E.C.E., Purdue University, December 2013. Performance-onDemand MEMS (PODMEMS): Electrical Control of Effective Mass, Damping, and Stiffness. Major Professor: Jason V. Clark. We propose the use of electrostatic force feedback to control the stiffness, damping, or mass of MEMS. If feedback forces are proportional to sensed displacement, velocity, or acceleration of a MEMS proo...

Vortex-induced vibrations (VIV) need to be accounted for in the design of marine structures such as risers and umbilicals. If a resonance state of the slender structure develops due to its interaction with the surrounding fluid flow, the consequences can be severe resulting in the accelerated fatigue and structural damage. Wake oscillator models allow to estimate the fluid force acting on the s...

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In this paper, the stress-related damping ratio formula of box girder with corrugated steel webs is introduced. Using response spectrum method, an iterative algorithm is proposed to calculate the seismic response and the stressrelated damping ratio under different seismic intensities. Based on a simply supported composite box girder bridge with corrugated steel webs, the stress-related damping ...

Ground-motion prediction equations that are used to predict acceleration values are generally developed for a 5% viscous damping ratio. Special structures and structures that use damping devices may have damping ratios other than the conventionally used ratio of 5%. Hence, for such structures, the intensity measures predicted by conventional ground-motion prediction equations need to be convert...

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...