Rolling bearing noise has become an aspect of increasing importance for the performance of rotating machinery, like electric motors and gearboxes. Generally, two aspects are important with regard to bearing noise, i.e. the transmission characteristics and the vibration generation characteristics. A potential source of vibrations are for example manufacturing imperfections of the di erent bearin...

High performance force sensors often encounter the problem of vibrations during the process of calibration and measurement. To address this problem, this paper presents a novel passive eddy current damper (ECD) for vibration suppression. The conceived ECD utilizes eight tubular permanent magnets, arranged in Halbach array, and a conductive copper rod to generate damping. The ECD does not requir...

Although it can be transformed by various electronic devices, the sound of the solid body electric guitar originates from, and is strongly linked with, the string vibration. The coupling of the string with the guitar alters its vibration and can lead to decay time inhomogeneities. This paper implements and justifies a framework for the study of decay times of electric guitar tones. Two damping ...

Concrete pump robots are used for very wi le operating ranges, so elastic deformations of the links must be taken into account . Concrete pumps demand actuators with a high power density, able to produce large forces which can be achieved by the use of hydraulically driven actuators . Hydrostatic differer tial cylinders are widely used because of their simple construction. For multilink flexil ...

In this paper, the problem of attitude control of a 1D non-linear exible spacecraft is investigated. Three controllers are presented. The rst is a non-linear dynamic inversion, the second is a linear -synthesis and the third is a composition of dynamic inversion and a -synthesis controller. It is assumed only one reaction wheel is used. Actuator saturation is considered in the design of control...

A historical introduction is given of the theory of normal forms for simplifying nonlinear dynamical systems close to resonances or bifurcation points. The specific focus is on mechanical vibration problems, described by finite degree-of-freedom second-order-in-time differential equations. A recent variant of the normal form method, that respects the specific structure of such models, is recall...

Conventionally, intracytoplasmic sperm injection (ICSI) in the mouse is conducted with piezo-drills that use a droplet of mercury for damping. The use of mercury causes concerns of toxicity and contamination. Although Fluorinert can be used as a substitute for mercury to reduce piezo-drill’s lateral vibration, the damping effect is not as satisfactory as mercury. In this work, a modified piezo-...

Broadband structural vibration can be suppressed through the connection of an electrical impedance to the terminals of a bonded piezoelectric transducer. This is referred to as piezoelectric shunt damping. Good nominal damping performance has been obtained with resonant shunts, but these shunts are highly sensitive to variations in structural resonance frequencies. In this paper, we present an ...

The goal of this work is to develop and investigate the properties of a new type of multifunctional composite which is based on multi-walled carbon nanotubes (MWCNT). The composite was prepared from a MWCNT “bucky paper” film which was sandwiched between two adhesive layers. Both two point probe and four point probe methods were used to test its mechanical strain sensing properties. The Young’ ...

As future astronomic missions will require more and more stringent resolution requirements, the high demand for an environment clean of vibrations and disturbance appears. This also leads to the need for high precision steering devices for fine pointing of sensitive optics with the highest possible accuracy. Several methods exist to reduce vibration levels: the first consists in isolating the s...