High density arrays of artificial hair sensors, biomimicking the extremely sensitive mechanoreceptive filiform hairs found on cerci of crickets have been fabricated successfully. We assess the sensitivity of these artificial sensors and present a scheme for further optimization addressing the deteriorating effects of stress in the structures. We show that, by removing a portion of chromium elec...

High density arrays of artificial hair sensors, biomimicking the extremely sensitive mechanoreceptive filiform hairs found on cerci of crickets have been fabricated successfully. We assess the sensitivity of these artificial sensors and present a scheme for further optimization addressing the deteriorating effects of stress in the structures. We show that, by removing a portion of chromium elec...

In this work new homogenization results are used to introduce a methodology for the design of structural components made from composite materials in the presence of stress constraints. A numerical method is developed for finding functionally graded materials that provide the maximum torsional rigidity while keeping the mean square stress inside the composite structure below a prescribed level. ...

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...

A hybrid longitudinal-torsional ultrasonic transducer is designed and fabricated in this research. The design of the transducer was performed using the FE method with ABAQUS software, with the aim of combining the longitudinal and torsional vibration modes. The transducer horn is then fabricated using a 4-axis milling machine. The PZT stacks are employed in order to excite the transducer. The t...

The speed of a torsional stress wave transmitted in a solid waveguide, that has a non-circular cross-section and is submerged in a liquid, is inversely proportional to the density of the liquid. Thus, by measuring the speed of the torsional stress wave, one can obtain information about the liquid's density or density-related characteristics such as liquid level and the mass composition of bi-ph...

AIMS 2D speckle tracking echocardiography allows for assessment of left ventricular (LV) torsional deformation as a composite function of the radial, longitudinal and circumferential fibres. We test the hypothesis that post-exercise LV torsional dynamics are more sensitive markers for myocardial dysfunction than resting measures, and better predictors for exercise capacity compared to post-exer...

The speed of torsional stress waves transmitted in solid waveguides submerged in a liquid depends, among other things, on the liquid's density and viscosity and the waveguides' cross-sectional geometry. By measuring the speed of torsional stress waves in two waveguides of different cross-sectional geometries, one can obtain both the liquid's density and viscosity. An online, real-time sensor fo...