The biodynamic response of the seated human body has been investigated with 20 males exposed to upward and downward shocks at 13 fundamental frequencies (1-16 Hz) and 18 magnitudes (up to ±8.3 ms-2). For 1- and 2- degree-of-freedom models, the stiffness and damping coefficients were obtained by fitting seat acceleration waveforms predicted from the measured force to the measured seat accelerati...

Adaptive feedforward broadband vibration (or noise) compensation is currently used when a correlated measurement with the disturbance (an image of the disturbance) is available. Most of the active vibration control systems feature an internal ”positive” mechanical feedback between the compensation system and the reference source (a correlated measurement with the disturbance). Such systems have...

The transmission of vibration to the adjacent buildings due to the traffic passing over Ghalemorghi Bridge in Tehran. has caused disruption to the inhabitants of the buildings. In order to investigate the vibration condition of the bridge, a dynamic loading test was performed and the output was analyzed using a non-parametric modal identification approach. In this article, the non-parametric mo...

Vibration was adopted to enhance the interface bonding of Mg–Al bimetal prepared by lost foam compound casting (LFCC) technique. The bimetallic composed three layers: layer I (Al3Mg2 and Mg2Si phases), II (Al12Mg17 III + δ-Mg eutectic structure). With increase in vibration acceleration, cooling rate increased, resulting decrease reaction duration that generates intermetallic compounds (IMCs) (i...

hand-arm vibration can cause vascular, neurological and musculoskeletal disorders, collectively named as hand-arm vibration syndrome. the chainsaw is a portable machine that exposes own operators to high levels of hand-arm vibrations. this research focuses on vibration transmissibility from chainsaw handle to wrist and arm of operator. the vibration acceleration signals necessary for evaluation...

Compared to other orthodontic acceleration methods such as drug, electric current, and laser, vibratory loading is less invasive easier use. But the optimal duration for load application has not been determined, nor can alveolar bone parameters be predicted after application. Therefore, this work examined mechanism of vibration-accelerated reconstruction established a numerical model simulating...

All living tissues and cells on Earth are subject to gravitational acceleration, but no reports have verified whether acceleration mode influences bone formation and healing. Therefore, this study was to compare the effects of two acceleration modes, vibration and constant (centrifugal) accelerations, on bone formation and healing in the trunk using BMP 2-induced ectopic bone formation (EBF) mo...

Technical preventive measures against vibration syndrome in the field of industrial health are reviewed in the present paper. The first technical prevention measure is to reduce vibration transmission from the tools to the operators. This measure employs vibration isolators between the handles and vibration sources of machine tools. Handles of tools using Neidhalt dampers, shear type rubber mou...