A 54-story steel, perimeter-frame building in downtown Los Angeles, California, is identified by a wave method using records of the Northridge earthquake of 1994 (ML=6.4, R=32 km). The building is represented as a layered shear beam and a torsional shaft, characterized by the corresponding velocities of vertically propagating waves through the structure. The previously introduced waveform inver...

By using dissipative system Lagrange equation, the strongly nonlinear dynamic equation of torsional vibration system is deduced, which contains a class of square and cube nonlinear rigidity and combination harmonic excitations. Bifurcation characteristics of the strongly nonlinear system are analyzed in the autonomous and non-autonomous situations by means of singular point stability theory and...

This work is devoted to investigation of the known problem of the discrepancy between the experimental and theoretical values for the barrier to internal rotation of the molecules comprised of a benzene ring and a π-conjugated substituent, such as benzaldehyde and benzoyl fluoride. The possible reasons of such discrepancy are considered. As a result the conclusion was drawn that the origin of t...

I would like to present our experiences with torsional and micro-coaxial technology on behalf of our French research group. My goal is to demonstrate to surgeons the transition from performing phacoemulsification with traditional longitudinal ultrasound to a micro-coaxial procedure using torsional technology. The impetus for the development of micro-incisional phacoemulsification was to provide...

PURPOSE To compare the intraoperative performances and postoperative outcomes of cataract surgery performed with longitudinal phacoemulsification and torsional phacoemulsification in moderate and hard cataracts. METHODS Of 85 patients who had senile cataracts, 102 eyes were operated on using the Infiniti Vision System. Preoperative examinations (slit lamp examination, mean central corneal thi...

Wet friction clutches play a critical role in a transmission system. The clutches progressively degrade while the transmission is under operational condition. If the clutches unexpectedly fail, then the complete transmission will fail. To avoid unexpected failures, a proper condition monitoring tool extended with a lifetime prediction method must be implemented. In order to achieve this, approp...

Heavy vehicle truck transmission gearbox housing is subjected to load fluctuations, harmonic excitation, gear meshing excitation, gear defects, varying speed and torque conditions. Transmission errors and internal excitations are the root cause of vibration and noise. The main objective of this research work is weight calculation and modal analysis of gearbox housing. For weight calculation fou...

Original scientific paper In this paper a systematic exploration of a typical two-stroke slow speed marine diesel propulsion shafting design space is performed. First, a set of the four most influential design parameters is defined, consisting of shafting stiffness, propeller, turning wheel and tuning wheel mass moments of inertia. Then, a full set of 625 design points is defined. For each desi...

In the design of high Quality factor (Q) micro or nano beam resonators, different dissipation mechanisms may have damaging effects on the quality factor. One of the major dissipation mechanisms is the thermoelastic damping (TED) that needs an accurate consideration for prediction. In this paper, thermoelastic damping of the longitudinal vibration of a homogeneous micro beam with both ends clamp...

The finite element method is employed for the flexural-torsional linear buckling analysis of beams of arbitrarily shaped composite cross-section taking into account generalized warping (shear lag effects due to both flexure and torsion). The contacting materials, that constitute the composite cross section, may include a finite number of holes. A compressive axial load is applied to the beam. The...