Damping of two deformation modes by one control loop has been demonstrated by simulation for a typcial 3 MW wind turbine. The vibration levels of the 2 and 3 in-plane modal modes were significantly reduced. Calculations with the aerodynamic code PHATAS showed an overall in-plane fatigue load reduction by ca 40%. The control loop includes a Kalman filter that estimates state variables for the mo...

The vibration fatigue durability of eutectic Sn37Pb and near-eutectic Pb-free Sn3.9Ag0.6Cu solders is quantified, based on test data available from the literature [1]. The tests use random broad-band excitation (between 20Hz & 2000Hz), on selected SAC and SnPb surface mount interconnect styles. In the test, step-stress excitation was applied in the out-of-plane direction by increasing the RMS e...

The heads of demembranated spermatozoa of the sea urchin Tripneustes gratilla, reactivated at different concentrations of ATP, were held by suction in the tip of a micropipette and vibrated laterally with respect to the head axis. This imposed vibration resulted in a stable rhythmic beating of the reactivated flagella that was synchronized to the frequency of the micropipette. The reactivated f...

This paper presents a simple analytical method to optimize the efficiency of two types of electrostatic Vibration Energy Harvesters (VEH): the out-of-plane (OPGC) and in-plane (IPGC) gap-closing converters. The electrical and mechanical behaviours of the transducer are addressed simultaneously, while a voltage limitation on the transducer’s terminals is set to prevent any damage in the conditio...

Tool wear is one of the most important considerations in machining operations, as it affects surface quality and integrity, productivity, and cost. The most commonly used model for tool life analysis is the one proposed by F. W. Taylor about a century ago. Although the extended form of this equation includes the effects of important cutting conditions on tool wear, tool life studies are mostly ...

To evaluate the effect of short-duration, high-load resistive exercise, with and without whole body vibration on lumbar muscle size, intervertebral disk and spinal morphology changes, and low back pain (LBP) incidence during prolonged bed rest, 24 subjects underwent 60 days of head-down tilt bed rest and performed either resistive vibration exercise (n = 7), resistive exercise only (n = 8), or ...

Finite element analysis methods have been used to calculate the effects of trimming bridges on the first several frequencies of vibration. Violin bridges and both standard and Belgian designs of cello bridges have been investigated. Calculations of both in-plane and out-of-plane vibrating modes have been made when the feet were rigidly fixed. In one case, no motion out-of-plane was permitted. I...

This paper reports a microfabricated piezoelectric MEMS inertial energy harvester that can scavenge high-frequency mechanical vibrations in all three dimensions with an active inner volume of only 55 mm. The device can generate 0.1 to 10.5 μW from out-of-plane vibrations (365-465 Hz), and 0.1 to 3.2 μW from in-plane vibrations (680-930 Hz) at 0.5 g acceleration input. The reported harvester is ...

We study the effects of a small curvature of the middle plane of a thickness-shear mode crystal plate resonator on its vibration frequencies, modes and acceleration sensitivity. Two-dimensional equations for coupled thickness-shear, flexural and extensional vibrations of a shallow shell are used. The equations are simplified to a single equation for thickness-shear, and two equations for couple...

We propose a new lateral force feedback device, the UltraShiver, which employs a combination of in-plane ultrasonic oscillation (around 30 kHz) and out-of-plane electroadhesion. It can achieve a strong active lateral force (400 mN) on the bare fingertip while operating silently. The lateral force is a function of pressing force, lateral vibration velocity, and electroadhesive voltage, as well a...