This paper investigates the seismic response control of a nonlinear benchmark building with a new re-centering variable friction device (RVFD). The RVFD consists of three parts: (i) a friction generation unit, (ii) a piezoelectric actuator, and (iii) shape memory alloy wires. The friction unit and piezoelectric actuator compose the first subcomponent of the hybrid device that is a variable fric...

One of the research goals in robotics is the development of home-help robots. The development of a control approach for a novel lightweight and multifunctional shape memory alloy (SMA) actuator scalable in force and length for robots is presented in this paper. The SMA actuator is based on lightweight bundles of thin wires of prestrainend shape memory alloy that change their length when heated ...

This paper presents a nonlinear, robust control algorithm for accurate positioning of a single degree of freedom rotary manipulator actuated by Shape Memory Alloy (SMA). A model for an SMA actuated manipulator is presented. The model includes nonlinear dynamics of the manipulator, a constitutive model of Shape Memory Alloy, and electrical and heat transfer behavior of SMA wire. This model is us...

− The paper present a simultaneous force and length variation mode shape memory alloy (SMA) robotic application. The robotic ankle contains 4 SMA actuators and a spherical articulation. In order to assure a high efficient robotic architecture, the mechanical and the control structure have to assure a real-time response to the work environment changes. The load variations or the difference betwe...

General thermo-mechanical behavior of composites reinforced by shape memory alloy fibers is predicted using a three-dimensional analytical micromechanical method to consider the effect of fibers activation. Composite due to the micromechanical method can be exposed to general normal and shear mechanical and thermal loading which cause to activate the shape memory alloy fibers within polymeric m...

Lightweight structures capable of changing their shape on demand are of interest for a number of applications, including aerospace, power generation, and undersea vehicles. This paper describes a bioinspired cellular metal vertebrate structure which relies on shape memory alloy (SMA) faces to achieve fully reversing shape change. The resulting vertebrate actuators can be combined with flexible ...

This paper presents a new isolation device concept using shape memory alloy elements, to evaluate the possibility of its application and to investigate the effectiveness in reaching the structural design goals compared with traditional isolation devices. Shape memory alloys (SMAs) are characterized by unique mechanical properties due to solid-solid transformation between phases of the alloy. Th...

Past earthquakes have illustrated the vulnerability of bridges to collapse as a result of large relative displacements at the hinges. In this study, Nitinol Shape Memory Alloy restrainer cables are evaluated for their potential to limit the relative hinge displacement in bridges. Shape Memory Alloys are unique metallic alloys that have the ability to sustain large elastic deformations. Experime...

A self-healing, metal matrix composite reinforced by shape memory alloy wires is simulated using finite element analysis. A one-dimensional constitutive model for SMA behavior is implemented as a user-defined truss element in ABAQUS. The matrix is brittle and a mode I crack is allowed to propagate through the specimen upon loading. During the loading process the wires undergo a martensitic phas...

In this paper, we present a new nerve cuff electrode based on a shape memory alloy (SMA) armature. This device is dedicated to functional electrical stimulation of the bladder in spinal cord injured patients. The SMA armature performs the closing of the electrode, making its installation around the nerve much easier, quicker and safer. Both remarkable mechanical properties of SlvIA materials na...