Smart Composite Structures

SN Applied Sciences, 2019

The composite structures embedding piezoelectric implants are developed due to their abilities of modifying mechanical properties according to the environment, of keeping their integrity, of interacting with human beings or with other structures. One way to functionalize a mechanical device consists in embedding the transducers inside the final composite structure via a "soft" layer. This layer consists of two plies sandwiching the transducers, impregnated with a resin compatible with the one of the final composite structures. The test structures are laminates made of a glass-fiber reinforced plastic with a polyester resin. In this paper, we propose to experimentally investigate the influence of the throughthe-thickness position of the "soft layer" on specific parameters of design such as eigenfrequencies, modal amplitude, damping ratio and Lamb wave propagation properties. Results show that the "soft" layer behavior can not be neglicted to predict the behavior of the final product in particular for the eigenfrequencies and the modal amplitudes. However, the "soft layer" has no impact on the damping ratio and the Time-of-Flight of a wave train.

2016

The project activity presides over the choice of materials and technical capacity within two dimensions of action: the previous knowledge and the tension about the future. That allowed us to identify the succession of the "technological and material" paradigms that have come and gone, featuring the project with the arrival of new materials and production processes. The advent of composite smart materials has challenged all the materials overturning the features.

Recently, thin piezoelectric foils or fibers with a thickness between 10µm and 30µm have been manufactured and used as sensor/actuator components of smart composite structures. The paper deals with the mathematical analysis and numerical simulation of such smart composite structures. A concept for laminated thin finite shell elements with active and passive layers considering three different approaches is introduced. In a test case the applicability of these different approaches is investigated and discussed. To verify the suitability of the algorithm for analyzing composite structures a practical example of a composite consisting of piezoelectric fibers embedded in a matrix material is considered. At first the introduced composite shell elements are used, where the piezoelectric fibers are modeled as active layers in a smeared form. At second a discrete concept is used, where the piezoelectric fibers are modeled as one-dimensional truss like finite elements which are embedded into conventional finite elements by the penalty technique. These two approaches are discussed and compared.

SPIE Proceedings, 1993

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Engineering Structures, 2002

Basic research in smart materials and structural systems and their development have demonstrated great potential for enhancing the functionality, serviceability and durability of civil and mechanical infrastructure systems and, as a result, offer the potential for significant contributions to the improvement of every nation's productivity, efficiency and quality of life. The intelligent renewal of aging and deteriorating civil and mechanical infrastructure systems includes efficient and innovative use of high performance sensors, actuators, materials, mechanical and structural systems. In this paper some examples of NSF-funded projects and research needs as well as some initiatives are presented.

2020

The Aim of the present study was to extol about advantages and applications of smart structures. Smart materials are important ingredients in present scenario Structures. Vital materials used in Smart Structures are Smart materials such as optical fibre based sensors, smart fluids, Ferro-magnetic Sensor's, shape memory alloys, Piezo-electric sensors. Smart materials which have the functions of actuator, sensor, self-healing and so forth, are to be used not only as advanced functional Materials but also as key materials to provide structures with smart functions. Smart systems sense the changes in the structure variations in vibration, noise and temperature. Processes the information and then responds appropriately to automatically correct deferential problems. They alert the structures to correct the malfunction, prevent damage and optimize performance. In the absence of mankind's vigilance it does its own vigilance.

Computational Methods and Experimental Measurements XIII, 2007

The adaptable mechanical structures in the form of Shell have found large developments and use in many applications, especially in the field of smart structures where the piezoelectric components are used as actuators and sensors. Many functional constraints prevent the control of a structure by elements reported on the surfaces of the object. Thus, the piezoelectric components necessary for the control of the structures will be integrated into this, i.e., in material, even the material of the wall. Certain work describes the manner and the performances of structures by using composite materials with thermoset matrices as structural support and piezoelectric components as the actuator or sensor elements. The current difficulties in recycling the thermoset materials are hindering the industrial development of such structures. For this reason, we propose to use composites with a thermoplastic matrix. Unfortunately, the current processes of achieving models in smart thermoplastic structures are not directly exploitable for the integration of components such as the piezoelectric actuators and sensors which are fragile and sensitive to temperature. This work evaluates the sizes typically reached in the process transformations of such composites with a thermoplastic matrix in order to be able to establish the behavior models for the realized structures. A thermo-mechanic testing method using dynamic mechanical analysis (DMA) is also proposed.

IEEE Transactions on Automatic Control, 2005

2013

Smart structures and material technologies are a tool for sharing the knowledge of how various building materials can significantly increase production and profit using advanced communication, collaboration and management technologies. The paper provides an overview of the types of materials available giving a new insight into innovative methods and techniques that will be available, and open new doors for advancement and improvement in the construction industry. The new technologies and materials discussed in this paper present a small fraction of the options that are available for use by industry. Key words: Smart structures, advanced communication, building materials.

Smart materials are expected to be an important ingredient of third-generation structures. Candidate smart materials for structural applications include optical fiber-based sensors, Ferro-magnetic sensors, shape memory alloys and piezoelectric sensors. As sensor technologies advance, periodical evaluations of their performance should be conducted to identify the best-performing sensors available for the measurement of structural responses (e.g. displacement, velocity, acceleration, strain, and stress) and detecting structural damage (e.g. cracking, fatigue and corrosion). Such evaluations should consider their performance (e.g. reliability, sensitivity, integrity, and robustness) not only as stand-alone sensors but more importantly when externally attached to structural members as well as internally embedded in concrete and FRP materials. In construction, smart materials and systems could be used in " smart " buildings, for environmental control, security and structural health monitoring e.g. strain measurement in bridges using embedded fiber optic sensors. Magneto-rheological fluids have been used to damp cable-stayed bridges and reduce the effects of earthquakes. In marine and rail transport, possibilities include strain monitoring using embedded fiber optic sensors. The paper discuss about types of smart materials, smart sensing Technology, components of smart structures, various sensors i.e. Fiber optic sensor, smart concrete, smart structure for seismic protection, health monitoring of smart structure.

This article presents a complete analytical model to study the role of the shape memory alloys (SMAs) on improvement the impact response of the smart composite structures. The role of some physical and geometrical parameters such as the volume fraction, the orientation and the location of the SMA wires on the contact force history, the deflection, the in-plane strains and stresses of the structures is investigated in details. Also the effect of density of the impactor to the plate ratio and the elastic modulus of the impactor to the plate ratio on the contact force history and the deflection of the plate is studied. The first order shear deformation theory as well as the Fourier series method was utilized to solve the governing equations of the composite plate analytically. The interaction between the impactor and the plate was modeled with the help of two degrees of freedom system consisting of springs-masses. The Choi's linearized contact model was used in the analysis. The results of the above research indicated that the use of the SMA wires inside the smart composite structures improve the global behavior of the structure against the impact. The smart composite structures damp more uniformly and rapidly after the impact.

Lecture Notes in Control and Information Sciences, 2007

The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

Materials Today, 2002

Smart structures are important because of their relevance to hazard mitigation, structural vibration control, structural health monitoring, transportation engineering, thermal control, and energy saving. Research on smart structures has emphasized the incorporation of various devices in a structure for providing sensing, energy dissipation, actuation, control or other functions. Work on smart composites has focused on the incorporation of a functional material or device in a matrix material for enhancing the smartness or durability, while that on smart materials has studied materials (e.g. piezoelectric) used for making relevant devices. However, relatively little attention has been given to the development of structural materials (e.g. concrete and composites) that are inherently able to provide some of the smart functions, so that the need for embedded or attached devices is reduced or eliminated, thereby lowering cost, enhancing durability, increasing the smart volume, and minimizing mechanical property degradation (which usually occurs in the case of embedded devices). Smart structures have the ability to sense certain stimuli and respond in an appropriate fashion, somewhat like a human being. Sensing is the most fundamental aspect of a smart structure. A structural composite which is itself a sensor is said to be self-sensing. It is multifunctional. This article focuses on structural composites for smart structures. It addresses cement-matrix and polymer-matrix

1994

Aeroelasticity-the interaction between structural deformation and aerodynamic loads-has a central role in the design of all lifting surfaces. Aeroelastic design requirements will translate into suffless criteria imposed on the lifting surface structure to prevent phenomena such as flutter and divergence or to increase the lift on a flexible surface. Satisfying these criteria may create the need for additional mass that creates a weight penalty on the design. Advanced materials such as composites help to keep the weight penalty to minimum because they are lighter, stiffer and can be tailored to control the deformations found to cause flutter and divergence. New activematerials such as piezoelectrics and shape memory alloys can actively control aeroelastic effects on demand, although their effectiveness is still unproven and concepts are still in their infancy. This talk will describe the history of aeroelastic tailoring with a special emphasis on recent efforts at active structural tailoring.