an attempt has been made to explore the general trends in the seismic response of planasymmetric structures when subjected to near-fault and far-fault ground motions. systems with structural wall elements in both orthogonal directions considering actual and common nonlinear behavior under bi-directional excitation were studied. idealized single-storey models with uni-axial eccentricity were emp...

This paper addresses control of structural vibrations using semi-active actuators that are capable of manipulating stiffness and/or producing variable stiffness. Usually vibration suppression is achieved using damping devices rather than stiffness ones. However, stiffness devices can produce large forces and have significant advantages for shock isolation purposes. In this work we use a passivi...

We describe a technique for measuring the stiffness of regenerate bone after leg lengthening. This allows early identification of slow healing by reference to normal patterns. We determined the time of removal of the fixator from clinical and radiological information independent of the stiffness result. In a series of 30 leg lengthenings there were no refractures when the tibial stiffness had r...

This paper presents an effectively unbiased nonlinear estimation scheme which identifies tire longitudinal stiffness and effective radius using GPS and ABS wheelspeed sensors. This estimation strategy is then used to experimentally identify the longitudinal stiffness and effective radius of a summer tire and a winter tire under several different test conditions. The data clearly shows that ther...

INTRODUCTION: It has been supposed that leg stiffness affect repeated jump performance, such as hopping. Previous study indicated that ankle joint stiffness is important in leg stiffness (Arampatzis et al. 2001). Furthermore, it was demonstrated that Achilles tendon properties could contribute to the total mechanical work during hopping (Lichtwark and Wilson 2005). On the other hand, it is know...

The paper investigates the effects of surface stiffness on the slip process aiming to obtain a better insight of the momentum transfer at nanoscale. The surface stiffness is modeled through the stiffness, κ, of spring potentials, which are employed to construct the thermal walls. It is shown that variations of stiffness, κ, influence the slip mechanism either toward slip or stick conditions. In...

Echocardiographic diastolic function (DF) assessment remains a challenge in atrial fibrillation (AF), because indexes such as E/A cannot be used and because chronic, rate controlled AF causes chamber remodeling. To determine if echocardiography can accurately characterize diastolic chamber properties we compared 15 chronic AF subjects to 15, age matched normal sinus rhythm (NSR) subjects using ...

For tasks requiring robot-environment interaction, stiffness control is important to ensure both stable contact motion and collision safety. The variable stiffness approach has been used to address this problem. We propose a hybrid dual actuator unit (HDAU) which is a novel variable stiffness unit design. The HDAU is composed of a hybrid control module based on an adjustable moment arm mechanis...

Particle stiffness is emerging as an important parameter in determining the cell uptake dynamics of particles. Understanding the effects of capsule stiffness on their biological behavior is essential for the development of polymer capsules as therapeutic carriers. Herein, we report the preparation of polysaccharide capsules via atom transfer radical polymerization-mediated continuous assembly o...

This masonry research investigated the differences in the static and dynamic stiffness for the seismic range of loads and frequencies for a pressed clay masonry wythe. The effective stiffness has been defined in Newtonian physics and Damage Mechanics. This research used the concept of measured stiffness defined as the measured stress field divided by the measured strain field. A two-part test r...