Publications
Shape memory alloys actuated upper limb devices: A review
Jun 1, 2023Journal Sensors and Actuators Reports
Publisher Elsevier
DOI https://doi.org/10.1016/j.snr.2023.100160
Issue 100160
Volume 5
Recently, significant efforts have been made to develop prostheses, soft rehabilitation, and assistive devices that enhance the quality of life of limb amputees and the activities of daily living (ADL) of stroke patients. Therefore, this present study provides a general overview of the current prosthetic, assistive, and rehabilitative devices with a focus on actuators that provide actuation via shape-memory alloys (SMA). Shape-memory alloy (SMA)-based actuators are the subject of considerable research as they possess high force-to-weight ratio, quiet operation, muscular mobility, bio-compatibility, and accessible design options, all of which can potentially be used to develop inventive actuating systems. Several studies have examined the use of SMA-actuated devices in the medical and engineering industry. They have also, more recently, been used to develop soft robotic systems. This present review primarily focuses on the characterization, number, type of actuator, degrees of freedom (DOF), weight, cooling technique, control strategies, and applications as well as the advantages and disadvantages of plate, spring, and wire-based SMA actuators. Composite-based upper limb SMA actuators were also reviewed and compared in terms of the matrix, reinforcing materials, SMA configuration actuator dimensions, and manufacturing method as well as their advantages and disadvantages. The findings indicate that, in the last few years, more studies have examined developing novel intelligent materials with which to improve hand flexibility. Therefore, SMA materials have a promising future in the development of intelligent designs for hand-robots. They may also be used to improve control robustness as well as the accuracy of hand functions for ADL and effective rehabilitation.
Experimental Study of a Dry Sliding Wear for a Different Materials Using a Pin-on-Disk Apparatus
Feb 1, 2021Journal Materials Science Forum
Publisher https://www.scientific.net/MSF.1021.78
DOI https://doi.org/10.4028/www.scientific.net/MSF.1021.78
Volume 1021
In the present work, an experimental investigation has been made of a dry sliding wear rate for aluminum, aluminum alloy (Al-Fe-V-Si), bronze, stainless steel 304 and structural steel ASTM A36, using a pin-on-disk apparatus under the effect of sliding speed and time at constant load. The materials were tested on two types of abrasive surfaces with a grit surface of 24 and 36. The applied load was equal to 2500 grams and the same load was used for all of the pins that were tested. The relative wear was indicated by the loss in length and loss in mass. The results show that the wear rate will directly proportional with sliding speed and time, and the stainless steel has less wear rate than the other materials.
Exergy and Energy Analysis of 150 MW Gas Turbine Unit: A Case Study
Jan 1, 2020Journal Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
Publisher AKADEMIA BARU
DOI https://doi.org/10.1016/j.snr.2023.100160
Issue 1
Volume 67
A study of the energy and exergy analysis of a 150 MW gas turbine plant was performed using Dataflow sheet Kirkuk unit. Applying the first and second law of thermodynamics across each component of the unit to determine losses have been used. The results showed that the first law efficiency in the compressor, combustion chamber, turbine, and exhaust gases was 93.34%, 85.52%, 94.11%, and 42.32%, respectively. The results were represented by the Sankei diagram, while the second law efficiency in the compressor, combustion chamber, turbine, exhaust gases were 93.3%, 89.52%, 95.57%, and 82.34%, respectively. The outcome of exergy analysis was represented by a Grasmann diagram while the energy analysis was represented by a Sankey diagram. The total thermal efficiency of the unit was 33.069%, while the exergy efficiency was 32.397%.
A numerical approach for solving problems in robotic arm movement
Jan 1, 2018Journal Production & Manufacturing Research
Publisher Taylor & Francis
DOI https://doi.org/10.1016/j.snr.2023.100160
Issue 1
Volume 6
Mechanical robotic arm control problems are examined in the numerical solutions for the second order system with the R.Kutta algorithms. The dynamics of a robotic arm be able to designated by a set of combined non-linear equations in the formula of coriolis, centrifugal effects and gravitational torques. This investigation attempted to minimize the error of an industrial robotic arm, which improves production systems. Results of comparisons illustrate the effectiveness of the numerical integrating algorithm based on the actual joint velocities and positions with each instant of time between the exact and numerical solutions. The obtained tables of data help to analyze the variation in the velocity and position joints at different time. The numerical results obtained by R.kutta -techniques perfectly match with the exact velocities. Depending on the relative error calculated at the obtained tables of results to reach the required …
Ultrasonic attenuation of (Al-SiC) particulate aluminum matrix composite
Jan 2, 2015Journal Al-Rafidain Engineering Journal (AREJ)
Publisher University of Mosul
DOI https://doi.org/10.33899/rengj.2015.101024
Issue 1
Volume 23
The present research deals with preparing (11) samples of composite materials with metal matrix represented by Aluminum alloy (AA3003) cast and particulate reinforced by (SiC) having particlesvolume fractions (5, 10, 15 Vol.%). The alloy matrix and composite materials were prepared by stir casting method. Stir casting technique wasused to increase the homogeneity distribution of the particles in alloy matrix. Average particlesizesof (75,106,150 m) were used. The aim of this study is to investigate the relationships between ultrasonic attenuation and stirrer speed, reinforcement contents of SiC reinforced Al-alloy (AA3003) composites. Attenuation (longitudinal and shear) were measuredusing the pulse-echo amplitude technique with normal and angle probes of (45, 60, and70) and frequencies of (2 and 4MHz). The results show an increase in volume fraction of particles causes an increase in attenuation. It was also found, that the ultrasonic attenuation decreases with increasing particle size. It was observed that an increases in stirrer speed, increases in the longitudinal ultrasonic attenuation.