Smart material

About: Smart material is a research topic. Over the lifetime, 3704 publications have been published within this topic receiving 74280 citations. The topic is also known as: intelligent material & responsive material.

3D constitutive modeling of electro-magneto-visco-hyperelastic elastomers: a semi-analytical solution for cylinders under large torsion-extension deformation

Abstract: The rise of a new class of smart materials known as electro-magnetorheological elastomers (EMREs) requires comprehensive understanding on their electro-magneto-visco-hyperelastic behaviors. The aim of this paper is to develop a generalized three-dimensional (3D) continuum-based framework of the electro-magneto-visco-hyperelastic behaviors of EMREs. The finite strain model is established based on the linear viscoelasticity theory and non-linear electro-magneto-elastic framework. As EMRE devices can be used in a cylindrical shape undergoing shear and normal stresses in many engineering applications like artificial muscles, a boundary-value problem simulating torsion-extension deformations of EMRE cylinders is developed in the finite strain regime and solved semi-analytically. The behaviors of EMRE cylinders under different loading conditions such as purely mechanical loading, purely electric loading as well as full coupling between mechanical, electric and magnetic loading are studied in detail. Influence of different parameters such as electric field, magnetic field, applied strain (-rate) and their coupling on the induced moment and axial force of the EMRE cylinder as well as its relaxation and creep under torsion-extension loading is also examined. It is shown that EMREs have adaptive capability and great potential in applications where the stiffness needs to be controllable. Due to simplicity and accuracy, the model is expected to be used in the future studies dealing with the analysis of EMREs in particular cylinders under torsion-extension developments like 4D printing of artificial EMRE-based cylindrical muscles.

Deformation and Viscoelastic Behavior of Polymer Gels in Electric Fields

Abstract: “Smart” polymer gels actively change their size, structure, or viscoelastic properties in response to external signals The stimuli-responsive properties, indicating a kind of intelligence, offer the possibility of new gel-based technology The article attempts to review the current status of our knowledge of electromechanical effects that take place in smart polymer gels Deformation and the mechanism of polyelectrolyte gel behavior in electric fields are first studied experimentally and then theoretically In particular, the swelling or bending is discussed in detail Particulate composite gels whose modulus of elasticity can vary in electric fields are revealed as a new smart material The driving force causing varying elastic modulus in electric fields is explained by a qualitative model based upon polarized particles Finally, applications of the two electromechanical effects are presented

Nanotechnology synthesis study: research report

Abstract: In this project, the authors investigated the potential nanotechnology applications in highway pavements mainly in two different categories: smart materials for pavement construction and sensors for transportation and pavement infrastructure condition monitoring. The smart materials are applicable to pavement construction including concrete, asphalt, aggregates, and pavement marking materials; and the sensors, including temperature sensor, strain sensor, pressure sensor, accelerometer, and moisture sensor, now form a reliable, accurate, low-cost network and are suitable for transportation and pavement infrastructure condition monitoring. Radio frequency (RF) microelectronic monitoring system (MEMS) technology is an advanced and innovative MEMS sensor technology which transmits MEMS sensor data wirelessly at a high speed securely. Ultra-low-cost RF MEMS sensors can be placed in pavements, bridges, and even inside concrete and asphalt in large quantities to form a local RF MEMS sensor network for different pavement infrastructure monitoring purposes. Nanomaterials are very attractive to the Texas Department of Transportation (TxDOT). Though nanomaterials are still in the research and development stages and are not cost effective for implementation at this time, nano-based sensors are getting mature and can be used in TxDOT for monitoring and other applications. In order to demonstrate the applications of nanotechnology in transportation systems, a fully functional smart stop sign is developed and tested. This smart stop sign is able to detect any malfunction including direction change, fall down, or tilt and report wirelessly to the TxDOT office using nanosensors and MEMS radio technology.

Detection of Non-Symmetrical Damage in Smart Plate-Like Structures

Abstract: A two-dimensional model for in-plane vibrations of a cantilever plate with a non-symmetrical damage is used in the context of defect identification in materials with piezoelectric ceramic patches bonded to their surface. These patches can act both as actuators and sensors in a self-analyzing fashion, which is a characteristic of smart materials. A Galerkin method is used to approximate the dynamic response of these structures. The natural frequency shifts due to the damage are estimated numerically and compared to experimental data obtained from tests on cantilever aluminum plate-like structures damaged at different locations with defects of different depths. The damage location and extent are determined by an enhanced least square identification method. Efficacy of the frequency shift based algorithms is demonstrated using experimental data.