In this work, a magnetorheological (MR) damper based above-knee prosthesis is design and evaluated based on its performance in swing phase and in stance phase. Initially, a dynamic system model for swing phase of a prosthetic leg incorporating a single-axis knee with ideal MR damper was built. The dynamic properties of the damper are represented with Bingham parametric model. From Bingham model...

Abstract The excellent properties of metallic glass (MG) films make them perfect candidates for the use in miniature systems and tools. However, their high coefficients friction (COFs) poor wear resistance considerably limit long-term performance nanoscale contact. We report fabrication a MG/graphene multilayer by repeated deposition Cu 50 Zr MG with alternating layers graphene. microstructure ...

In this investigation we develop a mathematical model to simulate the actuation of a multilayer metallic strip. In the first step of the model development, we employ the theory of Judy [4] and Timoshenko [5] to quantify the radius of curvature in the unimorph due to differing thermal coefficients in the constituent materials. The resulting radius of curvature is subsequently used to compute the...

The amorphous-to-microcrystalline phase transition of Ge in Pb/Ge multilayer geometry has been investigated as a function of layer thicknesses with the use of high-temperature x-raydiA'raction techniques. During crystallization, the modulation structure is destroyed and the Pb texture improves. In addition, the crystallization temperature decreases with decreasing amorphous Ge thickness and inc...

In this paper, a composite right/left-handed (CRLH) slab-type material excited by plane wave is proposed. It is composed of multilayer metallic patterns between dielectric substrates. The equivalent circuit is shown to design a balanced CRLH material. The balanced CRLH characteristics are measured. Next the CRLH material composed of four kinds of cells with different dispersion relation is desi...

An all-dielectric coaxial waveguide that can overcome problems of polarization rotation and pulse broadening in the transmission of optical light is presented here. It consists of a coaxial waveguiding region with a low index of refraction, bounded by two cylindrical, dielectric, multilayer, omnidirectional reflecting mirrors. The waveguide can be designed to support a single mode whose propert...

In this paper, the efficacy of magnetorheological (MR) dampers for seismic response reduction is examined. To investigate the performance of the MR damper, a series of experiments was conducted in which the MR damper is used in conjunction with a recently developed clipped-optimal control strategy to control a three story test structure subjected to a one-dimensional ground excitation. The abil...

Semi-active suspensions have drawn particular attention due to their superior performance over the other types of suspensions. One of their advantages is that their damping coefficient can be controlled without the need for any external source of power. In this study, three control approaches are implemented on a quarter-car model using MATLAB/Simulink. The investigated control methodologies ar...