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Electromechanical behavior of interface deformable piezoelectric bilayer beams / Chen, Fangliang in Journal of engineering mechanics, Vol. 136 N° 4 (Avril 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 4 (Avril 2010) . - pp. 413-428 Titre : Electromechanical behavior of interface deformable piezoelectric bilayer beams Type de document : texte imprimé Auteurs : Chen, Fangliang, Auteur ; Qiao, Pizhong, Auteur Article en page(s) : pp. 413-428 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Interfaces  Piezoelectricity  Integrated  systems  Intelligent  structures  Layered  systems  Coupling  Beams  Deformation. Résumé : An interface deformable piezoelectric bilayer beam model is proposed to study the electromechanical responses and interface stress distributions in an intelligent layered structure. Like most of current approaches in the literature, the layerwise approximation of electric potential is employed. While in contrast to the linear approximation where the induced electric field is ignored, the present model takes a quadratic variation of the potentials across the thickness, thus warranting an efficient and accurate modeling of the electric field. Completely different from the widely used equivalent single layer model, in which the whole laminate is assumed to deform as a single layer and thus has a smooth variation of the displacement field over the thickness, the present model considers each sublayer as a single linearly elastic Timoshenko beam perfectly bonded together and therefore with individual deformations. To ensure the continuity of deformations of two adjacent sublayers along the interface, two interface compliance coefficients are introduced, by which both the longitudinal and vertical displacement components along the interface of two sublayers due to the interface shear and normal stresses are taken into account. To assess the performance of the present model, a number of benchmark tests are performed for a piezoelectric bimorph and a piezoelectric-elastic bilayer beam subjected to (1) a force density normal to the upper face and (2) an electric potential applied to the top and bottom faces. A remarkable agreement achieved between the present solution and the finite element computations illustrates the validity of the present study. The present model not only predicts well the global responses (displacement, electric charge, etc.), but also provides excellent estimates of the local responses (through-thickness variations of electromechanical state, interface stress distributions, etc.) of the piezoelectric layered structures. The novel mechanics model of electroelastic layered structures presented can be used to efficiently and effectively characterize hybrid smart devices and develop/optimize new multifunctional materials. DEWEY : 620.1 ISSN : 0733-9399 En ligne : =136&fromissue=4&toissue=4&OUTLOG=NO&viewabs=JENMDT&key=DISPLAY&docID=15&page=1& [...] [article] Electromechanical behavior of interface deformable piezoelectric bilayer beams [texte imprimé] / Chen, Fangliang, Auteur ; Qiao, Pizhong, Auteur . - pp. 413-428. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 4 (Avril 2010) . - pp. 413-428 Mots-clés : Interfaces  Piezoelectricity  Integrated  systems  Intelligent  structures  Layered  systems  Coupling  Beams  Deformation. Résumé : An interface deformable piezoelectric bilayer beam model is proposed to study the electromechanical responses and interface stress distributions in an intelligent layered structure. Like most of current approaches in the literature, the layerwise approximation of electric potential is employed. While in contrast to the linear approximation where the induced electric field is ignored, the present model takes a quadratic variation of the potentials across the thickness, thus warranting an efficient and accurate modeling of the electric field. Completely different from the widely used equivalent single layer model, in which the whole laminate is assumed to deform as a single layer and thus has a smooth variation of the displacement field over the thickness, the present model considers each sublayer as a single linearly elastic Timoshenko beam perfectly bonded together and therefore with individual deformations. To ensure the continuity of deformations of two adjacent sublayers along the interface, two interface compliance coefficients are introduced, by which both the longitudinal and vertical displacement components along the interface of two sublayers due to the interface shear and normal stresses are taken into account. To assess the performance of the present model, a number of benchmark tests are performed for a piezoelectric bimorph and a piezoelectric-elastic bilayer beam subjected to (1) a force density normal to the upper face and (2) an electric potential applied to the top and bottom faces. A remarkable agreement achieved between the present solution and the finite element computations illustrates the validity of the present study. The present model not only predicts well the global responses (displacement, electric charge, etc.), but also provides excellent estimates of the local responses (through-thickness variations of electromechanical state, interface stress distributions, etc.) of the piezoelectric layered structures. The novel mechanics model of electroelastic layered structures presented can be used to efficiently and effectively characterize hybrid smart devices and develop/optimize new multifunctional materials. DEWEY : 620.1 ISSN : 0733-9399 En ligne : =136&fromissue=4&toissue=4&OUTLOG=NO&viewabs=JENMDT&key=DISPLAY&docID=15&page=1& [...]

Local delamination buckling of laminated composite beams using novel joint deformation models / Qiao, Pizhong in Journal of engineering mechanics, Vol. 136 N° 5 (Mai 2010) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 136 N° 5 (Mai 2010) . - pp. 541-550 Titre : Local delamination buckling of laminated composite beams using novel joint deformation models Type de document : texte imprimé Auteurs : Qiao, Pizhong, Auteur ; Shan, Luyang, Auteur ; Chen, Fangliang, Auteur Année de publication : 2010 Article en page(s) : pp. 541-550 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Delaminating  Buckling  Joints  Deformation  Transverse  shear  Composite  beams. Résumé : Local delamination buckling formulas for laminated composite beams are derived based on the rigid, semirigid, and flexible joint models with respect to three bilayer beam (i.e., conventional composite, shear-deformable bilayer, and interface-deformable bilayer, respectively) theories. Two local delamination buckling modes (i.e., sublayer delamination buckling and symmetrical delamination buckling) are analyzed and their critical buckling loads based on the three joint models are obtained. A numerical finite-element simulation is carried out to validate the accuracy of the formulas, and parametric studies of delamination length ratio, the transverse shear effect, and the influence of interface compliance are conducted to demonstrate the improvement of the flexible joint model compared to the rigid and semirigid joint models. The explicit local delamination buckling solutions developed in this study facilitate the design analysis and optimization of laminated composite structures and provide simplified and improved practical design equations and guidelines for buckling analyses. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=ASCERL&CURRENT=null [...] [article] Local delamination buckling of laminated composite beams using novel joint deformation models [texte imprimé] / Qiao, Pizhong, Auteur ; Shan, Luyang, Auteur ; Chen, Fangliang, Auteur . - 2010 . - pp. 541-550. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 136 N° 5 (Mai 2010) . - pp. 541-550 Mots-clés : Delaminating  Buckling  Joints  Deformation  Transverse  shear  Composite  beams. Résumé : Local delamination buckling formulas for laminated composite beams are derived based on the rigid, semirigid, and flexible joint models with respect to three bilayer beam (i.e., conventional composite, shear-deformable bilayer, and interface-deformable bilayer, respectively) theories. Two local delamination buckling modes (i.e., sublayer delamination buckling and symmetrical delamination buckling) are analyzed and their critical buckling loads based on the three joint models are obtained. A numerical finite-element simulation is carried out to validate the accuracy of the formulas, and parametric studies of delamination length ratio, the transverse shear effect, and the influence of interface compliance are conducted to demonstrate the improvement of the flexible joint model compared to the rigid and semirigid joint models. The explicit local delamination buckling solutions developed in this study facilitate the design analysis and optimization of laminated composite structures and provide simplified and improved practical design equations and guidelines for buckling analyses. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=ASCERL&CURRENT=null [...]