We report a demonstration of phase-resolved vibrometry, in which out-of-plane sinusoidal motion is assessed by heterodyne holography. In heterodyne holography, the beam in the reference channel is an optical local oscillator (LO). It is frequency-shifted with respect to the illumination beam to enable frequency conversion within the sensor bandwidth. The proposed scheme introduces a strobe LO, ...

Crossties and cable networks are used on cable-stayed bridges to mitigate wind-induced stay vibration. A nonlinear free-vibration analysis of a cable network with random oscillation amplitudes is presented in this study. Specifically, a nonlinear restoring-force spring model is introduced at the crosstie to simulate in-plane network free vibration at large amplitudes. The current constitutive m...

In this article, the design of asymmetric bimorph piezoelectric ceramic transducer with loose and fixed edges and with parallel electric excitation is studied. Rectangular piezoelectric ceramic transducers in flexural vibration with straight and parallel nodal lines of vibration are studied. The transducer’s radiation in a plane perpendicular to the surface of the transducer and parallel to the...

When the head of a sea-urchin sperm is held in the tip of a micropipette and vibrated laterally, the flagellum beats in phase with the imposed vibration. Rotation of the plane of pipette vibration around the head axis induces a corresponding rotation of the plane of beating, in both live and reactivated sperm. Detailed analysis of the waveforms occurring at different stages of this rotation sho...

Laser triangulation displacement sensor is an important tool in non-contact displacement measurement; it is widely used in the measurement of 3D contour, thickness, width, position, and vibration. It uses diffuse reflection light as sensor signal, which is formed by laser scattering on object surface. The diffuse reflection light is converged to a light receiver on the focal plane by lens imagi...

The heads of live spermatozoa of the sea urchin Hemicentrotus pulcherrimus were held by suction in the tip of a micropipette mounted on a piezoelectric device and vibrated either laterally or axially with respect to the head axis. Within certain ranges of frequency and amplitude, lateral vibration of the pipette brought about a stable rhythmic beating of the flagella in the plane of vibration, ...

Rotating machinery, including machining spindles, industrial turbomachinery, and aircraft gas turbine engines, are very commonly used in industry. One major problem faced by these machineries is the harmful, imbalance-induced vibration. Many methods have been developed to reduce this vibration: o!-line balancing methods [1], on-line active balancing methods using mass redistribution devices [2}...