The paper presents a mathematical model of a piston compressor which is part of nitrogen-oxygen gas generator. Taking into account the structural parameters of the compressor, as well as the suction and pressurization valves, such model allows to obtain the dynamics of the pressure amplitude under the compressor’s piston together with the vibration velocity and vibration acceleration that are t...

The period of vibration is a fundamental parameter in the force-based design of structures as this parameter defines the spectral acceleration and thus the base shear force to which the building should be designed. This paper takes a critical look at the way in which seismic design codes around the world have allowed the designer to estimate the period of vibration for use in both linear static...

This paper presents the design of a MEMS capacitive vibration-to-electricity energy converter with integrated mechanical switches for precise timing control. Integrated lateral mechanical contact switches have the advantage of zero leakage current, low energy consumption and synchronous operation. The new design can provide an output power of 31μW at a 40V output voltage from the targeted vibra...

To mimic in vivo vibration of vocal fold cells, we studied the controllability and range of frequency, acceleration, duration, and shear stress in a new bioreactor attachment. The custom multiwell disc appliance fits into a commercially built rheometer, together termed a torsional rheometer bioreactor (TRB). Previous attachments to the TRB were capable of 50–100 Hz vibrations at relatively high...

A new, self-recording, vibratory sensation meter measures temporary threshold shifts of vibratory sensation (TTSv) on a finger tip. After exposure to hand-transmitted vibration with exposure frequencies 63 Hz, 200 Hz and 500 Hz, and levels of acceleration 1 g, 2 g, 4 g and 8 g, fingertip measurements were obtained. Temporary threshold shift immediately after the vibratory exposure (TTSv,0) was ...

Most active vibration isolation systems that try to a provide quiescent acceleration environment for space-science experiments have utilized linear design methods. In this paper, we address adaptive control augmentation of an existing classical controller that combines a high-gain acceleration inner-loop feedback together with a low-gain position outer-loop feedback to regulate the platform abo...

OBJECTIVES To investigate changes in digital circulation during and after exposure to hand transmitted vibration. By studying two frequencies and two magnitudes of vibration, to investigate the extent to which haemodynamic changes depend on the vibration frequency, the vibration acceleration, and the vibration velocity. METHODS Finger skin temperature (FST), finger blood flow (FBF), and finge...

Riveting tasks in aircraft manufacturing results in exposure to vibration from both rivet guns and bucking bars. Long term exposure to vibration has been associated with symptoms of vibration white finger and musculoskeletal disorders. Four different bucking bars of the same shape but different material and mass characteristics (90% tungsten, >90% tungsten, cold rolled and stainless steel) were...

A growing issue in the area of vehicular ride comfort is that of child safety seats. Postural, thermal and vibrational comfort considerations are finding their way into child seat design. This paper makes some observations regarding the current state of child safety seat design, then goes on to present the results of vibration tests performed over two road surfaces using two child seats and two...

Various methods for evaluating ride quality in automobiles are investigated by means of a field study involving two different automobiles, seventy-eight different passengers, and eighteen different roadway sections. Passenger rating panels were used to obtain subjective evaluation of the various rides, and measured vibration spectra were compared on the basis of various evaluation techniques to...