Abstract The torsional vibration of marine propulsion shafting has been studied for more than a century. With abundant research achievements and experiences, a systematic approach of vibration calculation has been put forward for ship industrial applications. However, literature review indicates that when processing the gear transmission in the shaft line, the meshing motion has been treated as...

OBJECTIVES This study compared the mechanical properties of various instruments for canal exploration and glide-path preparations. MATERIALS AND METHODS The buckling resistance, bending stiffness, ultimate torsional strength, and fracture angle under torsional load were compared for C+ file (CP, Dentsply Maillefer), M access K-file (MA, Dentsply Maillefer), Mani K-file (MN, Mani), and NiTiFle...

Electrostatically actuated torsional micromirrors are key elements in Micro-Opto-Electro- Mechanical-Systems. When forced by means of in-plane comb-fingers, the dynamics of the main torsional response is known to be strongly non-linear and governed by parametric resonance. Here, in order to also trace unstable branches of the mirror response, we implement a simplified continuation method with a...

SMIP94 Seminar Proceedings Abutment stiffnesses are determined directly from the earthquake motions recorded at the US 1011 Painter Street Overpass using a simple equilibrium-based approach without finite-element modeling of the structure or the abutment-soil systems. The calculated abutment stiffnesses, which include the effects of soil-structure interaction and nonlinear behavior of the soil,...

We present a dynamically tunable mechanism of wave transmission in 1D helicoidal phononic crystals in a shape similar to DNA structures. These helicoidal architectures allow slanted nonlinear contact among cylindrical constituents, and the relative torsional movements can dynamically tune the contact stiffness between neighboring cylinders. This results in cross-talking between in-plane torsion...

Complex rotating machine trains especially trains including electric machines are subject to the most varied and often most severe torsional disturbances. If shaft or rotating component failures occur as a result of torsional oscillations, the consequences can be catastrophic. In this paper a comprehensive model and simulation method using analytical formulations are developed to study both ste...

Trains including reciprocating machines are subject to the most varied and often most severe torsional disturbances in comparison to other machinery classes. If crankshaft or rotating component failures occur as a result of shaft torsional oscillations, the consequences can be catastrophic. In this paper a new comprehensive model and solution method using analytical formulations are developed t...

latticed columns are frequently used in industrial steel structures. in some countries these built-up columns might be even used in other types of steel structures such as residential and commercial buildings. besides, latticed columns are parts of skeletons of many historic buildings all around the world. to analyze a steel structure with latticed columns a more accurate numerical model for su...

We present a dynamically tunable mechanism of wave transmission in one-dimensional helicoidal phononic crystals in a shape similar to DNA structures. These helicoidal architectures allow slanted nonlinear contact among cylindrical constituents, and the relative torsional movements can dynamically tune the contact stiffness between neighboring cylinders. This results in cross-talking between in-...

In this paper the effect of parametric amplification in MEMS-based air-flow hairsensors is studied. With an AC-voltage controlled torsional stiffness the rotation of the hair can be influenced. With the appropriate amplitude, phase and frequency, the rotation of the torsional hair system is increased with respect to the case without parametric amplification. Therefore, parametric amplification ...