Research regarding the risk of developing hand-arm vibration syndrome after exposure to impact vibration has produced conflicting results. This study used an established animal model of vibration-induced dysfunction to determine how exposure to impact vibration affects peripheral blood vessels and nerves. The tails of male rats were exposed to a single bout of impact vibration (15 min exposure,...

Taking as examples of South Gate tunnel project and Metro Line 2 crossing project in Xi’an, this paper analyses the dynamic response of motor vehicle and train loads acting on a tunnel structure .based on finite element model of three-dimensional dynamics. By comprehensive use of load numerical fixation method and analytic formula method, the vibrating load curves of motor vehicle and subway tr...

Nonlinear vibration of parabolic springs employed in suspension system of a freight car has been studied in this paper. First, dynamical behavior of the springs is investigated by using finite element method and the obtained results are then used in vibration analysis of a railway freight car. For this purpose, dynamics of a parabolic spring subjected to a cyclic excitation has been studied ...

To facilitate the damping matching of dampers for vehicle passive suspensions, this paper proposes an analytical matching method of the optimal piecewise linear damping characteristics curve. Based on the vehicle vibration model, taking the suspension dynamic deflection as the constraint, by the vibration acceleration and the wheel dynamic load, an objective function about the relative damping ...

In this paper, multi-objective uniform-diversity genetic algorithm (MUGA) with a diversity preserving mechanism called the ε-elimination algorithm is used for Pareto optimization of 5-degree of freedom vehicle vibration model considering the five conflicting functions simultaneously. The important conflicting objective functions that have been considered in this work are, namely, vertical accel...

Active vibration isolation from an arbitrarily, structurally complex receiver is considered with respect to the impacts of structure flexibility on the openand closed-loop system characteristics. Specifically, the generally weak influence of flexibility on the open-loop transfer function in case of total force feedback, in contrast to acceleration feedback, is investigated. The open-loop system...

OBJECTIVES This study was undertaken to assess concurrent mechanical stresses from shock, vibration, and noise to which a critically ill neonate is exposed during emergency transfer. METHODS For neonates transported by a French specialized emergency medical service, we measured and analyzed 27 physical parameters recorded during typical transport by ambulance and by helicopter. The noninvasiv...

Orthopaedic rehabilitation of osteoporosis by muscle vibration exercise is investigated theoretically using Wolff's theory of strain-induced bone 'remodelling'. The remodelling equation for finite amplitude vibration to be transmitted to the bone via muscle corresponds to a slowly time-varying non-linear dynamic system. This slowly time-varying system is governed by a Riccatti equation with rap...

Many workers are exposed to vibration in their industrial environment. Vibration can be transmitted through a vehicle seat or a hand-held power tool. Excessive vibration exposure may cause health problems and therefore it is important that the worker's vibration exposure is assessed, which may require measurement by the equipment manufacturer or the employer. Human exposure to vibration may be ...