The objective of the study was to evaluate the ability of a nonlinear ultrasound technique, the so-called nonlinear resonant ultrasound spectroscopy (NRUS) technique, for detecting early microdamage accumulation in cortical bone induced by four-point bending fatigue. Small parallelepiped beam-shaped human cortical bone specimens were subjected to cyclic four-point bending fatigue in several ste...

Hysteretic dynamical systems are challenging to control due to their hard nonlinearity and difficulty in modeling. One type of systemwith hysteretic dynamics that is gaining use in aerospace systems is the shape-memory alloy-based actuator. These actuators provide aircraft and spacecraft systems with the ability to achieve component-level or vehicle-level geometry or shape changes. Characteriza...

The use of hysteretic control for current regulators is very applicable to LED drivers. It is easy to sense the current in the FET but this is comprised of only the positive ramp. The FET current waveform makes it simple to turn the switch off at the correct peak value of drain current; however, the information from the negative ramp is not available in the path of the FET. This paper examines ...

This paper describes a method to calculate the loss modulus of viscoelastic polymer material at high frequencies based on vibrothermography. The is coated surface metallic substrate and resonant mechanical vibrations are generated in substrate. vibrating coating undergoes hysteretic heating because its nature. By measuring temperature by solving heat transfer equation, intensity dissipated esti...

The damping in a carbon fiber reinforced plastic (CFRP) laminate is greater than that which occurs in most metallic materials. In the supercritical regime, the damping can trigger unstable whirl oscillations, which can have catastrophic effects. The vibrations occurring in a supercritical composite drive shaft are investigated here in order to predict instabilities of this kind. A simply suppor...