Landing gear is a structure that is mounted under the fuselage and helps the aircraft in takeoffs and landings. The most important duty of landing gear is the control of vibration exerted on the system through the shock absorber which is a common component to all the landing gear. Considering the importance of this issue, the necessity of investigating shock absorber with features such as high ...

This study is concentrated on the natural frequencies and mode shapes of a simple three-member space frame coupled with a dynamic vibration absorber. The dynamic vibration absorber is modeled as a six-degree-of-freedom mass-spring system. For the first time, the free vibration of an elastic structure with a six-degree-of-freedom mass-spring system is found. Each member of the space frame has un...

it has been proved that natural frequencies are stationary at the natural modes. also it has been shown that at the first mode it is a minimum and for systems with finite number of degrees of freedom the highest frequency is maximum (reference 1 and 2). beyond these statements nothing more can be said about the behavior of the natural frequencies without defining precisely the manner in which t...

The zero bias stability, which is an important performance parameter for vibratory cylinder gyroscopes, is high sensitive to temperature change. It is considered that the varying temperature makes the vibration mode axes unstable, which has significant influence on the zero bias stability. This paper will investigate this problem in detail. First, the relationships between the angular positions...

A novel approach to fault detection and diagnosis of gearbox based on Ensemble Empirical Mode Decomposition (EEMD) and Teager Kaiser Energy Operator (TKEO) technique is presented. The time-domain vibration signal of the gearbox with gear crack fault is measured. EEMD can adaptively decompose the vibration signal into a series of zero mean Amplitude Modulation-Frequency Modulation (AM-FM) Intrin...

The vibration of an elastic beam experiencing vortex-induced vibration is numerically analyzed through a wake-oscillator model using the finite differences method. The influence of the excited mode, the initial velocity, the shedding pulsation and the mass ratio on the energy transfer among modes and the vibration amplitude is determined. Multiple frequencies are detected, and the power spectra...

Energy dissipation experienced by vibrating microcantilever beams immersed in fluid is strongly dependent on the mode of vibration, with quality factors typically increasing with mode number. Recently, we examined energy dissipation in a new class of cantilever device that embeds a microfluidic channel in its interior-the fundamental mode of vibration only was considered. Due to its importance ...

Ultrasonic linear piezomotors have several advantages compared to electromagnetic motors in specific applications such as in high-vacuum conditions and where no magnetic field is allowed. These compact directdrive motors are fast, but low speeds and high-resolution positioning are difficult to obtain. On the other hand, several non-resonant piezosteppers were developed, resulting in very accura...

We present measurements of the acoustic vibrations of single gold nanorods deposited on a glass substrate immersed in air and water by ultrafast pump-probe spectroscopy. The nanorods display two vibration modes, the breathing mode and the extensional mode. The damping time of the two modes is influenced by the environment, and a reduction of the quality factor is observed when the particles are...

This paper investigates the lateral vibration of single-layered graphene sheets based on a new theory called doublet mechanics with a length scale parameter. After a brief reviewing of doublet mechanics fundamentals, a sixth order partial differential equation that governs the lateral vibration of single-layered graphene sheets is derived. Using doublet mechanics, the relation between natural f...