The Experts below are selected from a list of 12390 Experts worldwide ranked by ideXlab platform
L. M. Wang - One of the best experts on this subject based on the ideXlab platform.
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Effect of electrothermal annealing on the transformation behavior of TiNi shape memory alloy and two-way shape memory Spring actuated by direct electrical current
Physica B-condensed Matter, 2004Co-Authors: Z.g. Wang, X.d. Feng, Shi-liang Zhu, J. Deng, L. M. WangAbstract:Abstract In this work, the effect of electrothermal annealing on the transformation characterization of TiNi shape memory alloy and the electrothermal actuating characteristics of a two-way shape memory effect (TWSME) Extension Spring were investigated with direct electrical current. The results showed that with increasing direct electrical current density, the B2→R-phase transformation shifts to a lower temperature and R-phase→B19′ shifts to a higher temperature in the cooling process. When annealing electrical current density reached 12.2 A/mm 2 , the R-phase disappeared and austenite transformed into martensite directly. The electrothermal annealing was an effective method of heat treatment in a selected part of shape memory alloy device. The electrothermal actuating characteristics of a TWSME Spring showed that the time response and the maximum elongation greatly depended on the magnitude of the electrical current.
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Two-way shape memory effect of TiNi alloy coil Extension Springs
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003Co-Authors: Z.g. Wang, S. Zhu, Jiyan Dai, L. M. WangAbstract:A two-way shape memory effect (TWSME) Spring that could elongate upon heating and contract upon cooling was obtained by constrained annealing and thermo-mechanical training. The effect of heat treatment and thermomechanical training on the TWSME and the effect of training on the transformation temperatures had been studied by elongation-temperature, electrical resistance measurements and differential scanning calorimetry (DSC). The TWSME recovery rate of Extension Spring increases with increasing the training cycles and increases to a saturation value. The inverse martensitic and martensitic temperatures decreased with increasing thermo-mechanical training cycles. (C) 2003 Elsevier B.V. All rights reserved.
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Design of TiNi alloy two-way shape memory coil Extension Spring
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2002Co-Authors: Zhongxing Wang, X.d. Feng, Li-bin Lin, Shi-liang Zhu, L.p. You, L. M. WangAbstract:Abstract This work presents a study of the development of the two-way shape memory effect (TWSME) by themomechanical training and its degradation due to working cycles in a shape memory alloys (SMAs) Spring. A TWSME Extension Spring that could extend upon heating and contract upon cooling was obtained by constrained annealing and thermomechanical training. A stable TWSME recovery rate can reach 60–70% after training for 200 cycles. The investigation showed that constrained annealing temperature and the thermomechanical training procedure had a great effect on the TWSME. After 1000 working cycles, the TWSME recovery rate still maintained at 45% stably. The effect of the thermomechanical training on transformation characters was also investigated by differential scanning calorimetry (DSC). The inverse martensitic transformation temperatures increased and martensitic transformation temperatures decreased with increasing thermomechanical training cycles, which was attributed to the dislocations introduced into the TiNi shape memory alloys.
Hong Zhou - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Variable-Diameter Helical Extension Springs
Volume 4A: Dynamics Vibration and Control, 2016Co-Authors: Riyaz Mohammed, Hong ZhouAbstract:Helical Extension Springs store energy and provide resistance to tensile loads that are applied through appropriate Spring ends. Typical Spring ends include different types of hooks or loops. Both ends of a helical Extension Spring are attached to other components. When the two components move apart and their distance is increased, the helical Extension Spring exerts a tensile force between the two components and tries to decrease their distance. There are various applications for helical Extension Springs that include automobiles, toys, hand tools, agriculture machines, textile machines, and medical devices. The common configuration of helical Extension Springs uses straight cylindrical shape that has constant coil diameter and pitch. Unlike regular helical Extension Springs, variable-diameter helical Extension Springs do not employ constant coil diameter. Their variable coil diameter enables them to produce desired force deformation relationships and reduce stress concentration. The distinctive features of variable-diameter helical Extension Springs also raise their synthesis challenges. To surmount these challenges, a method is introduced in this paper to model and design variable-diameter helical Extension Springs. The configuration of a synthesized Spring is described by a composite parametric curve. The entire Spring is defined by its control parameters. Synthesizing the Spring is systematized as optimizing its control parameters. Examples on modeling, analyzing and designing Springs are presented in the paper to demonstrate the procedure and verify the effectiveness of the introduced synthesis method.Copyright © 2016 by ASME
Mohammed Riyaz - One of the best experts on this subject based on the ideXlab platform.
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Analysis and synthesis of variable diameter helical Extension Springs
Texas A&M University- Kingsville, 2019Co-Authors: Mohammed RiyazAbstract:Helical Extension Springs store energy and offer resistance to tensile loads that are applied to Spring ends that include types of hooks or loops. Both ends of a helical Extension Spring are attached to other components. These Springs exert a force, i.e., tensile force, between the two components which are moving apart and decrease their distance. There are various applications for helical Extension Springs that include automobiles, toys, hand tools, agriculture machines, textile machines, medical devices, educational devices, lock machines, Spring mattresses, watches, and airsoft guns. These Springs have constant pitch and coil diameter which uses straight cylindrical shape as configuration. Variable coil diameter allows to generate desired force deformation relationships and reduce stress concentration. The characteristic features of variable-diameter helical Extension Springs also increase their synthesis goals, a method is presented in this thesis to model and design variable-diameter helical Extension Springs. The constituents of a generated Spring are defined by a composite parametric curve. Synthesizing the Spring is schematized as improving its influenced parameters. Examples on modeling, analyzing, and designing Springs are performed in the thesis to demonstrate the procedure and verify the effectiveness of the presented synthesis method
Géza F. Kogler - One of the best experts on this subject based on the ideXlab platform.
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Instrumented Ankle–Foot Orthosis: Toward a Clinical Assessment Tool for Patient-Specific Optimization of Orthotic Ankle Stiffness
IEEE ASME Transactions on Mechatronics, 2017Co-Authors: Nicholas B. Bolus, Caitlin N. Teague, Omer T. Inan, Géza F. KoglerAbstract:In this paper, we detail the design and operation of the instrumented ankle-foot orthosis (i AFO), a clinical assessment tool that can be used to quantify the functional consequences of selectively modifying orthotic ankle joint stiffness, particularly for individuals with locomotor deficits such as foot drop. We discuss the sensing capabilities of the system, which include ankle joint kinematics and kinetics, electromyography, and orthosis interface pressures. We further describe the mechanical design of the device, which allows for user-defined manipulation of orthotic stiffness through an interchangeable Extension Spring mechanism. Finally, we demonstrate a validation of the iAFO's capabilities by presenting results both of benchtop testing and of a preliminary human-subject study. Future work will include in-depth signal analyses of gait parameters and algorithmic development for patient-specific orthosis optimization.
Tulshi Bezboruah - One of the best experts on this subject based on the ideXlab platform.
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A Non-intrusive Opto-mechanical Technique for the Measurement of Liquid Level
2019 2nd International Conference on Innovations in Electronics Signal Processing and Communication (IESC), 2019Co-Authors: Nityananda Hazarika, Tulshi BezboruahAbstract:In this paper, we present an opto-mechanical technique suitable for measurement of liquid level with a very high resolution. In the propose technique, the change in the liquid level in the cylindrical container, attached to the bottom of a vertically suspended helical Extension Spring, causes corresponding change in the elongation length of the Spring. The change in the elongation length eventually changes the distance between a diverging light source and a photoresistor. The repeated experimental observations show that the proposed technique has good resolution, very small non-linearity, high repeatability and negligible hysteresis error.
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A Novel Method for Measurement of Linear Displacement by Using Extension Spring and Flex Sensor
2018 2nd International Conference on Power Energy and Environment: Towards Smart Technology (ICEPE), 2018Co-Authors: Nityananda Hazarika, Hidam Kumarjit Singh, Tulshi BezboruahAbstract:This paper describes a new method for measuring linear displacement by employing Extension Spring and commercially available flex sensor. In the proposed method, an Extension Spring has been vertically suspended over a common reference plane. Further, the flex sensor is bent in U-shape and attached with the Spring. Displacement is measured by pulling down the lower end of the Spring towards the reference plane. Displacement of the Spring causes bending radius of the flex sensor to vary. This eventually varies resistance of the attached flex sensor. Signal processing electronics performs resistance - to - voltage conversion and digitalization of the generated signals.
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A Novel Optical Method to Measure Weight by Using Linear Extension Spring
IEEE Sensors Letters, 2018Co-Authors: Ram Kishore Roy, Nityananda Hazarika, Hidam Kumarjit Singh, Tulshi BezboruahAbstract:We present a novel optical method suitable for measuring the weight of solid and liquid materials in small quantities. In this method, a longitudinal elongation of helical Spring, resulting from an applied weight, increases the separation between a diverging light source and a photoresistor. As a result, resistance of the photoresistor increases with applied weight. An experimental observation shows that the method has good resolution, small nonlinearity, insignificant hysteresis, and good repeatability with a dynamic range of 100 g. This method has the potential for a use in precise and accurate measurement of mass and weight of biochemical reagents, precious metals, gemstones, etc., in small quantities.
