Purpose: To compare the efficacy and phacoemulsification parameters of torsional mode versus the combined torsional and longitudinal ultrasound mode in hard cataract of Egyptian patients. Methods: This randomized comparative study evaluated eyes 1, 7, and 30 days after phacoemulsification with an Infiniti Vision System using the torsional mode versus the combined torsional (100%) and longitudin...

A B S T R A C T Pump shafts used for power generation are susceptible to fatigue cracking while often in near-continuous operation. Technology based on torsional vibration is under development for condition-based assessment of shaft health. The focus of this paper is on the relationship between a crack, which propagated due to bending loads, and the torsional stiffness of the shaft. An analytic...

This paper presents a novel method to nonlinearly investigate the dynamics of the coupled axial and torsional vibrations in the circular cross section beam of the steam turbine generator using the FFT analysis. Firstly, the coupled axial and torsional vibrations of a beam are proved by equivalent law of shearing stress and different boundary conditions. Then, a nonlinear mathematical model of t...

Abstract Experimental modal analysis is of great importance for the dynamic characterization structures. Existing methods typically employ out-of-plane forces excitation and measure acceleration or strain analysis. However, these encountered difficulties in some cases. In this work, we proposed an in-plane method based on thickness-shear ( d 15 ) piezoelectric transducers. Through combination d...

Using the static analysis of ANSYS 19, longitudinal, radial, and tangential beam specimens spruce, Scots pine, beech were subjected to stress strain under symmetrical four-point bending asymmetrical bending. The effects wood grain on surface specimen its properties transverse longitudinal at center studied experimentally. results show that method is suitable for testing elastic modulus, Poisson...

in this paper, evaluation of torsional stiffness in beam and slab bridge deck elements is presented. a beam and slab bridge decks structurally behave as a grillage. a grillage has an efficient transverse load distribution due to transverse asymmetric load. in the case of bridge deck without transverse beams in the span, transverse load distribution depends on the torsional stiffness of longitud...

In this paper, the effects of transverse cracks on rotating shaft are studied. According to earlier works, crack shaft failure decrease the critical speed of the shaft and also exhibit a nonlinear vibration behaviour leading to increases the amplitude of 1X and 2X harmonics (first and second order of rotational speed in torsional vibration). This suggests that the application of order analysis ...

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...