...John W. Sanders; Daniel J. Inman Many oscillatory systems of engineering and scientific interest ( e.g. , mechanical metastructures) exhibit nonproportional damping, wherein the mass-normalized damping and stiffness matrices do not commute. A new modal analysis technique for nonproportionally...

...J. Gregory McDaniel; Alyssa Liem; Allison Kaminski Over the past century, a number of scalar metrics have been proposed to measure the damping of a complex system. The present work explores these metrics in the context of finite element models. Perhaps the most common is the system loss factor...

...K. P. McNamara; J. S. Love; M. J. Tait The nonlinear response of a series-type pendulum tuned mass damper-tuned liquid damper (TMD-TLD) system is investigated in this study. The TLD is mounted on the pendulum TMD in series to remove the need for costly viscous damping elements. Since the response...

... that this is due to a considerable increase of damping, caused by the sensor cables, affecting mainly the higher-frequency modes. Table 2 Modal properties estimated via single-degree-of-freedom fit for configuration with and without accelerometers attached Configuration with accelerometers...

... for publication in the J ournal of V ibration and A coustics . 01 09 2020 13 04 2021 14 04 2021 04 05 2021 attenuation resonance accumulator flow rate venturi effect acoustic emission damping flow-induced noise and vibration noise control structural acoustics...

... system by a set of spring and damping elements. A complex coordinate notation was helpful to make a concise physical description of the in-phase and out-of-phase wobbling motions between the bodies. If its properties are properly adjusted, all modes interact (indicating veering or crossings between...

... motion at 120 Hz under cutting head excitation. Note: The critical damping ratio is set at 5%. This is because vibration motion could be compared under the same displacement standard: ( a ) equal-span placement and ( b ) ST-DVA: 120 Hz. Vibration motion at 120 Hz under cutting head excitation. Note...

...Hangyuan Lv; Michael J. Leamy This paper explores the addition of small stubs with anechoic terminations (termed herein “anechoic stubs”) as a means of damping and/or removing vibration modes from planar frame structures. Due to the difficulties associated with representing anechoic boundary...

... identification process of two moving loads. The effects from moving loads’ traveling direction, measurement location arrangements, number of participant measurements, and damping ratios are considered in the studies under noisy disturbance conditions. Results show that the stiffness of the translational...

... by compression or friction between the particles or between particles and the container wall [ 13 – 18 ]. Studies on such particle assemblage dampers have reported damping characteristics using glass beads, steel balls, or elastomer particles, which have the structure of linear motion type, where rods coming out...

... the response characteristics of a linear oscillator for which the damping coefficient varies periodically in time. The Floquet theory is used to determine the effects of mean plus cyclic damping on the Floquet multipliers. An approximate Floquet solution, which includes an exponential part and a periodic part...

... that, by increasing the sublayer number, the present solution approaches the exact one. After validating the formulation and program, we investigate the acoustic vibration characteristics in nanoparticles. These include the effects of material anisotropy, damping, and core–shell imperfect interface on the vibration...

...Lukas Woiwode; Johann Gross; Malte Krack It is well-known that nonlinear dry friction damping has the potential to bound the otherwise unboundedly growing vibrations of self-excited structures. An important technical example are the flutter-induced friction-damped limit cycle oscillations...

... overlooked their damping effects through careful analytical model developments. The objective of the current work is to present analytical models for cable-harnessed structures that also include the damping effects in their vibration response. Obtaining simple, low-order and high-fidelity models are highly...

...Wenshuo Ma; Jingjun Yu; Yiqing Yang The multi-degrees-of-freedom (MDOF) tuned mass damper (TMD) has proven its ability to suppress multiple modes of interest, and it possesses less mounting space than multiple single degree-of-freedom TMDs of equal damping mass. However, it is challenging...

... TLD equipped with damping screens. A linearized equivalent mechanical model capable of capturing the fundamental sloshing mode response of an annular TLD is presented. An experimental shake table testing program is completed to assess the performance of the model. Thirty-six frequency sweep tests...

... of the filling fraction on the bandgap absorption properties. The geometries studied here were printed in plastic due to the availability of 3D printers. damping materials in vibration and acoustics noise control 20 02 2020 25 06 2020 25 06 2020 22 07 2020 Contributed...

...Guebum Han; Utku Boz; Lejie Liu; Corinne R. Henak; Melih Eriten Articular cartilage is a thin layer of a solid matrix swollen by fluid, and it protects joints from damage via poroviscoelastic damping. Our previous experimental and simulation studies showed that cartilage-like poroviscoelastic...

..., reported bandgaps are compared and an infinite unit cell model (band structure) is validated. The introduction of material loss factor (material damping) resulted in a broadband vibration attenuation zone spread throughout the frequency spectrum. Compared to a standard multiresonant pillared-plate model...

... proposes a model calibration technique that identifies the joint parameters of a four-parameter Iwan element based on the nonlinear natural frequencies and damping ratios computed with quasi-static modal analysis (QSMA). The QSMA algorithm is applied to the full-order finite element model (FEM) to obtain...