Experimental techniques for estimating the two-dimensional dynamic stiffness of the human arm over a wide range of conditions have been developed. A robotic manipulator has been developed to create loads against which subjects perform various tasks and also to impose perturbations onto the endpoint of the arm to allow estimation of its mechanical properties. The manipulator can produce static e...

It might be assumed that increasing the thickness of a glove would reduce the vibration transmitted to the hand. Three material samples from an anti-vibration glove were stacked to produce three thicknesses: 6.4, 12.8 and 19.2 mm. The dynamic stiffnesses of all three thicknesses, the apparent mass at the palm and the finger and the transmission of vibration to the palm and finger were measured....

Based on the coupling model of nonlinear oil-film force and nonlinear seal fluid force, a nonlinear dynamic model of rotor system with rub-impact fault is set up. The dynamic characteristics of the system were studied with numerical simulation and the effects of airflow excited force, rubbing gap and stiffness parameters on movement characteristics of the rotor were analyzed. The results indica...

Experimental results demonstrate that μ synthesis provides an excellent tool for increasing the dynamic stiffness of thrust magnetic thrust bearings. Accurate system modeling and appropriate uncertainty descriptions are critical to obtaining such results and are described in detail. Both complex μ and mixed μ synthesis were used to design controllers. The performance of the μ controllers is com...

We discuss the growth process of a crystalline phase out of a metastable over-compressed liquid that is brought into contact with a crystalline substrate. The process is modeled by means of molecular dynamics. The particles interact via the Lennard-Jones potential and their motion is locally thermalized by Langevin dynamics. We characterize the relaxation process of the solid-liquid interface, ...

Recent developments in dynamic legged locomotion have focused on encoding a substantial component of leg intelligence into passive compliant mechanisms. One of the limitations of this approach is reduced adaptability: the final leg mechanism usually performs optimally for a small range of conditions (i.e. a certain robot weight, terrain, speed, gait, and so forth). For many situations in which ...

Increased vascular stiffness is fundamental to hypertension, and its complications, including atherosclerosis, suggest that therapy should also be directed at vascular stiffness, rather than just the regulation of peripheral vascular resistance. It is currently held that the underlying mechanisms of vascular stiffness in hypertension only involve the extracellular matrix and endothelium. We hyp...

Abstract: This paper studies the dynamic response of a wind turbine gearbox under different excitation conditions. The proposed 4 degree-of-freedom (DOF) dynamic model takes into account the key factors such as the time-varying mesh stiffness, bearing stiffness, damping, static transmission error and gear backlash. Both the external excitation due to wind and the internal excitation due to the ...