دانلود رایگان مقاله لاتین ساختار کامپوزیت الکترو از سایت الزویر
عنوان فارسی مقاله:
تغییر شکل ساختار کامپوزیت الکترو فعال انعطاف پذیر و تاشو
عنوان انگلیسی مقاله:
Deformations of flexible and foldable electro-active composite structures
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Structures integrated with smart materials, such as shape memory, magnetostrictive and piezoelectric materials, known as smart structures, are appealing for the development of new generation of autonomous systems with sensing and adaptation ability. Smart structures that are lightweight, flexible and deformable into various configurations find many applications in aerospace industry, biomedicine and robotics. Examples of applications are morphing wings, micro air vehicles, soft robots, artificial skins, vascular stents, and electronic packaging systems. Flexible structures are macroscopically compliant, which are often in the forms of long filaments and thin sheets that can be deformed into various geometrical shapes. Depending on the geometrical shapes considered, flexible structures can experience relatively small strains while undergoing large rotations [1,2]. In this work, we study the deformation of smart flexible planar structures with integrated thin piezoelectric patches, in which deformations and shape changes are controlled by electric field inputs prescribed to the piezoelectric actuators. We consider two piezoelectric materials for the patches, which are, lead zirconate titanate (PZT) ceramics and active fiber composites (AFC). When piezoelectric ceramics based actuators are considered, it limits the strains in the flexible structures and large deformations in such structures are predominantly due to large rotations. One solution to enhance deformations in piezoelectric ceramics based actuators is to form active fiber composites (AFC) which have PZT fibers embedded in a polymeric matrix. AFC was originally proposed by Ben and Hagood [3]. Flexible structures are typically undergoing large displacements (large stretch and/or large rotation) when subjected to external stimuli, whose motion cannot be sufficiently described based on linearized kinematics. There have been several studies on analyzing three-dimensional deformation of thin plates and shells with nonlinear geometries [4–6] mainly under mechanical loads. Moderate and large deformations of plates are governed by coupled nonlinear differential equations for which analytical solutions are available only for a few cases involving simple geometries and loading conditions [7]. There have been limited studies on analyzing nonlinear deformations of plates and shells integrated with piezoelectric actuator. Chen and Chen [8] studied piezoelectric layered-plates by adopting von Karman theory and using finite difference method in order to obtain solutions to the governing equations for moderate deformations, e.g. von Karman strains. Xue et al. [9] solved nonlinear partial differential equations for moderate deflections of thin plates made of piezoemagnetic and piezoelectric materials under transverse mechanical loads by using Bubnov– Galerkin method. One of the commonly used numerical techniques for solving large deformations of plates and shells is finite element method(FEM). In FE analysis with geometric nonlinearity, three Lagrangian kinematic descriptions have been formulated: (a) total Lagrangian (TL), (b) updated Lagrangian (UL) and (c) co-rotational (CR). For the TL approach, the governing equations are written with respect to the original configuration of the body while for the UL method, the reference configuration is updated at each step or increment, and the equations are formulated with respect to the equilibrated configuration from the previous step. The CR description is based on a separation of rigid body displacements from the deformational displacements, which can be used for analyzing structures undergoing large deformation mainly due to rotations while the strains remain relatively small. In the CR method, the deformational component is typically formed based on small strain measures, although other general strain measures are also possible. The governing equations are expressed with respect to the current configuration obtained from the rigid body motion of the original configuration. The CR formulation was first introduced by Wempner [10] in 1969 and Belytschko et al. [11] in 1973. Since then, it has been adopted by researchers for studying deformation of structures and multi-body systems which often involves large ratio of rigid body motions to total deformation [12–16]. Felippa and Haugen [17] summarized the existing CR formulations and presented a unified theoretical framework for co-rotational finite element (CRFE) in geometrically nonlinear analyses of structures. Recently, by using the CR formulation, triangular flat shell elements were constructed by researchers for nonlinear analysis of shells and plates subjected to small strains and large rotations due to mechanical loads [18–20]. Cai and Atluri [21,22] considered also moderate strains by adopting the von-Karman nonlinear strains in the rotated element frame. In all of the above studies, the CR formulation has been considered for flexible linear elastic bodies under mechanical loadings. To the best of our knowledge, the CRFE method has not been used for studying deformations in flexible elastic as well as viscoelastic composite plates/shells actuated by non-mechanical stimuli.
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کلمات کلیدی:
Mechanisms and Materials of Flexible and Stretchable Skin Sensors www.mdpi.com/2072-666X/8/3/69/pdf by Y Zhao - 2017 Feb 28, 2017 - Rapid growth in electronic technology yields miniaturized electronic devices and recent ... Some wearable devices are based on flexible and stretchable skin sensors, which ... reaction force from the sensor in response to the deformation, allowing less ...... Stretchable and foldable silicon integrated circuits. Mechcomp3: 3rd International Conference of Mechanics of Composite https://books.google.com/books?isbn=889385029X Antonio J.M. Ferreira, Erasmo Viola, Francesco Tornabene - 2017 - Technology & Engineering We present analyses on flexible and foldable smart composite beams and ... the equations that govern the deformations of the electro-active composite plates. Flexible and Curved Focal Plane Arrays for Image Sensing Applications https://books.google.com/books?id=yCDmfajKIM4C ... for integrated circuits with linear elastic responses to extreme mechanical deformations”. ... “Stretchable and Foldable Silicon Integrated Circuits”. ... University [5] PR Newswire, “Flexible Electronics to Revolutionize Electronic Devices”. Flexible and Stretchable Piezoelectric Sensor with Thickness-Tunable ... https://www.ncbi.nlm.nih.gov/pubmed/27571166 by SH Park - 2016 - Cited by 4 - Related articles Sep 12, 2016 - Flexible and Stretchable Piezoelectric Sensor with Thickness-Tunable Configuration of Electrospun Nanofiber Mat and Elastomeric Substrates. ... stimuli and able to perceive the corresponding deformation at a resolution of 1 μm. ... still be effective under harsh conditions of repetitive stretching and folding. Soft Actuators: Materials, Modeling, Applications, and Future ... https://books.google.com/books?isbn=4431547673 Kinji Asaka, Hidenori Okuzaki - 2014 - Technology & Engineering ... active artificial pupil showing amoeba-like pseudopodial deformation. ... Smela E, Ingana ̈s O, Lundstro ̈m I (1995) Controlled folding of micrometer-sized structures. ... Angew Chem Int Ed 44:2410–2413 Bar-Cohen Y (ed) (2001) Electroactive ... Chevrot C, Teyssie ́ D (2011) Flexible solid polymer electrolytes based on ...
