Class Mm2 Research Articles

Nonlinear transient coupled thermo-electromechanical dynamic responses of the piezoelectric structure with the high-order temperature-dependent material properties

This work aims to study the nonlinear transient coupled thermo-electromechanical dynamic responses of the piezoelectric structure with the high-order temperature-dependent material properties. The multi-field coupling nonlinear model is established based on the non-Fourier thermoelasticity theories by introducing the function of high-order temperature dependency of the arbitrary material property. The virtual work principle and the nonlinear finite element approach are proposed to investigate the two-dimensional case of the orthotropic rectangular piezoelectric plate of the crystal class mm2 subjected to the zonal transient heating loads. The influences of the high-order temperature-dependent material parameters on the structural responses and wave propagations are discussed.

Beyond π-π Stacking: Understanding Inversion Symmetry Breaking in Crystalline Racemates.

The design of noncentrosymmetric (NCS) solid state materials, specifically how to break inversion symmetry between enantiomers, has intrigued chemists, physicists, and materials scientists for many years. Because the chemical complexity of molecular racemic building units is so varied, targeting these materials is poorly understood. Previously, three isostructural racemic compounds with a formula of [Cu(H2O)(bpy)2]2[MF6]2·2H2O (bpy = 2,2'=bipyridine; M = Ti, Zr, Hf) were shown to crystallize in the NCS space group Pna21, of polar, achiral crystal class mm2. In this work, we synthesized five new racemic compounds with the formula [Cu(H2O)(dmbpy)2]2[MF6]2·xH2O (dmbpy = 4,4'/5,5'-dimethyl-2,2'-bipyridine; M = Ti, Zr, Hf). Single crystal X-ray diffraction reveals that the five newly synthesized compounds feature equimolar combinations of Δ- and Λ-Cu(dmbpy)2(H2O)2+ complexes that are assembled into packing motifs similar to those found in the reported NCS structure but all crystallize in centrosymmetric (CS) space groups. Seven structural descriptors were created to analyze the intermolecular interactions on the assembly of Cu racemates in the CS and NCS structures. The structural analysis reveals that in the CS structures, the inversion center results from parallel heterochiral π-π stacking interactions between adjacent Cu racemates regardless of cation geometries, hydrogen bonding networks, or interlayer architectures, whereas in the NCS structure, nonparallel heterochiral π-π interactions between the adjacent Cu racemates preclude an inversion center. The parallel heterochiral π-π interactions in the CS structures can be rationalized by the restrained geometries of the methyl-substituted ligands. This work demonstrates that the introduction of nonparallel stacking can suppress the formation of an inversion center for an NCS racemate. A conceptual framework and practical approach linking the absence of inversion symmetry in racemates is presented for all NCS crystal classes.

Thermally nonlinear non-Fourier piezoelectric thermoelasticity problems with temperature-dependent elastic constants and thermal conductivity and nonlinear finite element analysis

In non-isothermal conditions, numerous experimental and theoretical investigations reveal that the elastic constants and thermal conductivity in piezoelectric solids depend on temperature distribution. This work aims to investigate thermally nonlinear non-Fourier piezoelectric thermoelasticity problems with temperature-dependent elastic constants and thermal conductivity. The nonlinear time-domain finite element method is developed to directly solve nonlinear finite element governing equations, which maximally avoids the precision losses within the applications of the integrated transformation method. As a numerical example, the developed method is applied to analyze nonlinear transient thermo-electromechanical responses of a two-dimensional orthotropic piezoelectric plate of crystal class mm2. The achieved results reveal that temperature-dependent thermal conductivity and elastic constants remarkably affect the structural dynamic responses, whilst thermal wave or elastic wave will travel faster and the electrical energy harvesting ability is significantly elevated.

Three-dimensional piezo-thermo-mechanical analysis for a finite cylindrical composite panel composed of cross-ply and piezoelectric laminate

The exact three-dimensional piezo-thermo-mechanical solution for a finite cylindrical composite panel composed of cross-ply and piezoelectric laminate is presented in this article. The panel is simply supported at four end edges and is subjected to thermo-mechanical loadings on its top and bottom surfaces, respectively. The piezoelectric layers are polarized along radial direction as a sensor. The variables are expanded layerwise in Fourier series to satisfy the boundary conditions at the simply supported ends. As an example, a cross-ply laminated cylindrical panel made of alumina fiber reinforced aluminum composite, associated with a piezoelectric material of crystal class mm2 is calculated. Furthermore, some numerical results for the temperature change, the displacement, stresses, electric potential, and electric displacement distributions are shown in figures and briefly discussed.

Specific propagation directions of acoustic waves for piezoelectric and nonpiezoelectric media

I reanalyze the problem of the existence of longitudinal normals inside the symmetry planes of piezoelectric crystals belonging to the symmetry class mm2. The equations determining components of longitudinal normals situated outside the symmetry planes for media of this symmetry are discussed. It is proven that nonpiezoelectric media of rhombic symmetry could have 4 or 8 distinct acoustic axes. Examples of nonpiezoelectric elastic media of monoclinic symmetry without acoustic axes are given. The method of determination of the components of acoustic axes for piezoelectric media of arbitrary symmetry is presented. With the help of this method, I discuss the problem of acoustic axes for piezoelectric media of the symmetry class mm2.

Transient piezothermoelastic problems of smart composite structures bonded to a piezoelectric layer

In the present article, we give exact solutions for the transient piezothermoelastic problems of rectangular composite plates and cylindrical composite panels bonded to a piezoelectric layer of crystal class mm2, subject to partial heat supply. Numerical calculations are carried out for several smart composite structures bonded to a piezoelectric layer, which is used as a sensor or an actuator. Some numerical results for temperature change, displacement, stress and electric potential distributions in a transient state are shown. Copyright © 2005 John Wiley & Sons, Ltd.

Transient piezothermoelastic analysis of a cross-ply laminated cylindrical panel bonded to a piezoelectric actuator

In this study, the theoretical treatment of transient piezothermoelastic problem is developed for a cross-ply laminated cylindrical panel bonded to a piezoelectric actuator due to nonuniform heat supply. By using the exact solutions for cross-ply laminate and piezoelectric layer of crystal class mm2, the theoretical analysis of a transient piezothermoelasticity is developed for a simple supported cylindrical composite panel under the state of plane strain. Analysis of a piezothermoelastic problem leads to an appropriate electric potential applied to the piezoelectric layer which suppresses the induced thermoelastic displacement in the radial direction at the midpoint on the free surface of the cross-ply laminate. Some numerical results for the temperature change, the displacement, the stress in a transient state when the transient thermoelastic displacement is controlled are shown in figures.

A porous supramolecular architecture from a copper(II) coordination polymer with a 3D four-connected 8(6) net.

A novel coordination polymer [[Cu(L(1))(L(2))(H(2)O)].5H(2)O](n) (1), where L(1) =1,1'-(1,4-butanediyl)bis(imidazole) and L(2) = m-phthalate anion, has been obtained by using an unusual crystallization process. It crystallizes in the orthorhombic space group Pna2(1), which belongs to the crystal class mm2, with a = 9.0521(18), b = 15.401(3), and c = 17.141(3) A, alpha = beta = gamma = 90 degrees, V = 2389.7(8) A(3), and Z = 4. The complex 1 composing a porous supramolecular architecture displays unprecedented four-connected topology of an 8(6) net in coordination polymer chemistry. Thermal gravimetric analysis (TGA) and X-ray powder diffraction (XRPD) patterns for 1 are discussed in detail.

Transient piezothermoelastic problem for a laminated composite strip composed of angle-ply and piezoelectric laminae

This paper is concerned with the theoretical treatment of transient piezothermoelastic problem which is developed for a laminated composite strip composed of angle-ply laminae and a piezoelectric material of crystal class mm2, subject to nonuniform heat supply in the width direction. We obtain the exact solution for the two-dimensional temperature change in a transient state and the transient piezothermoelastic response of a simple supported composite strip under the state of generalized plane deformation. As an example, numerical calculations are carried out for a angle-ply laminated composite strip made of an alumina fiber reinforced aluminum composite, associated with a piezoelectric layer of a cadmium selenide solid. Some numerical results for temperature change, displacement, stress and electric potential distributions in a transient state are shown in figures. Furthermore, the influence of the thickness of the piezoelectric layer on the thermal stress or electric field is investigated.

Control of transient thermoelastic displacement of an angle-ply laminated cylindrical panel bonded to a piezoelectric layer

In this study, the theoretical analysis of a control of transient thermoelastic displacement is developed for an angle-ply laminated cylindrical panel bonded to a piezoelectric layer due to nonuniform heat supply. By using the exact solutions for angle-ply laminate and piezoelectric layer of crystal class mm2, the theoretical analysis of a transient piezothermoelasticity is developed for a simply supported cylindrical composite panel under the state of generalized plane deformation. Analysis of a piezothermoelastic problem leads to an appropriate electric potential applied to the piezoelectric layer which suppresses the induced thermoelastic displacement in the radial direction at the midpoint on the free surface of the angle-ply laminate. Some numerical results for the temperature change, the displacement, the stress in a transient state when the transient thermoelastic displacement is controlled are shown in figures.

Transient piezothermoelasticity for a cylindrical composite panel composed of angle-ply and piezoelectric laminae

This paper is concerned with the theoretical treatment of transient piezothermoelastic problem is developed for a cylindrical composite panel composed of angle-ply laminae and piezoelectric material of crystal class mm2, subject to non-uniform heat supply in the circumferential direction. We obtain the exact solution for the two-dimensional temperature change in a transient state, and transient piezothermoelastic response of a simple supported cylindrical composite panel under the state of generalized plane deformation. As an example, numerical calculations are carried out for an angle-ply laminated composite panel made of alumina fiber reinforced aluminum composite, associated with a piezoelectric layer of a cadmium selenide solid. Some numerical results for temperature change, displacement, stress and electric potential distributions in a transient state are shown in figures. Furthermore, the influence of thickness of the angle-ply laminate is investigated.

Transient piezothermoelasticity for a cylindrical composite panel composed of cross-ply and piezoelectric laminae

This paper is concerned with the theoretical treatment of transient piezothermoelastic problem is developed for a cylindrical composite panel composed of cross-ply laminae and piezoelectric material of crystal class mm2, subject to nonuniform heat supply in the circumferential direction. We obtain the exact solution for the two-dimensional temperature change in a transient state, and transient piezothermoelastic response of a simply supported cylindrical composite panel under the state of plane strain. Some numerical results for temperature change, displacement, stress and electric potential distributions in a transient state are shown in figures. Furthermore, the influence of thickness of the cross-ply laminate on thermal stress or electric field are investigated.

919 アングルプライ積層材料に圧電材料が接着された複合帯板の非定常圧電熱弾性問題

In this study, the theoretical analysis of transient piezothermoelasticity is developed for a composite strip consisting of an angle-ply laminate and a piezoelectric material of crystal class mm2,subject to nonuniform heat supply in the width direction. We obtain the exact solution for the two-dimensional temperature change in a transient state, and transient piezothermoelasticity of a simply supported combined strip under the state of generalized plane deformation. As an example, numerical calculations are carried out for an angle-ply laminated strip made of alumina fiber-reinforced aluminum composite, associated with a piezoelectric strip made of a cadmium selenide solid. Some numerical results for the temperature change, the displacement, the stress, electric potential, and electric displacement distributions in a transient state are shown in figures. Furthermore, those distributions in the transient state when the transient thermoelastic displacement is controlled are shown in figures.

Control of transient thermoelastic displacement of a two-layered composite plate constructed of isotropic elastic and piezoelectric layers due to nonuniform heating

In this study, the theoretical analysis of the control of transient thermoelastic displacement is developed for a two-layered composite rectangular plate constructed of an isotropic elastic and a piezoelectric layer due to nonuniform heat supply. The transient three-dimensional temperature in a two-layered composite rectangular plate is analyzed by the methods of Laplace and finite cosine transformations. Exact solutions for isotropic elastic and piezoelectric plates of crystal class mm2 are used in the theoretical analysis. A three-dimensional transient piezothermoelastic solution is developed for a simple-supported combined plate. The analysis yields an appropriate electric potential which when applied to the piezoelectric plate, suppresses the induced thermoelastic displacement in the thickness direction at the midpoint on the free surface of the isotropic plate. As an example, numerical calculations are carried out for an isotropic rectangular plate made of steel, bonded to a piezoelectric plate of cadmium selenide. Some numerical results are shown for temperature change, displacement and stress in transient state, when the transient thermoelastic displacement are controlled.

Control of the transient thermoelastic displacement of a functionally graded rectangular plate bonded to a piezoelectric plate due to nonuniform heating

In this study, the theoretical analysis of a control of the transient thermoelastic displacement is developed for a functionally graded rectangular plate bonded to a piezoelectric plate due to nonuniform heat supply. Assuming that the functionally graded plate has nonhomogeneous thermal and mechanical material properties in the thickness direction, the three-dimensional temperature in a transient state and the three-dimensional transient thermal stresses of a simply supported plate for a functionally graded material are analyzed by introducing the theory of laminated composites as a theoretical approximation. By using the solution for a functionally graded plate and the exact solution for a piezoelectric plate of crystal class mm2, the theoretical analysis of three-dimensional transient piezothermoelasticity is developed for a simply supported combined plate. the analysis of a piezothermoelastic problem leads to an appropriate electric potential applied to the piezoelectric plate which suppresses the induced thermoelastic displacement in the thickness direction at the midpoint on the free surface of the functionally graded plate. As an example, numerical calculations are carried out for a functionally graded rectangular plate made of zirconium oxide and titanium alloy, bonded to a piezoelectric plate of a cadmium selenide solid. Some numerical results when the transient thermoelastic displacements are controlled are shown in figures.

Transient Piezothermoelasticity of a Piezoelectric Cylindrical Panel due to Nonuniform Heat Supply in the Circumferential Direction.

This paper is concerned with the theoretical treatment of transient problem of piezothemoelasticity involving a cylindrical panel of crystal class mm2 due to nonuniform heat supply in the circumferential direction. We obtain the exact solutions for the two-dimensional temperature change in a transient state and the transient piezothermoelasticity of a simple supported cylindrical panel under the state of plane strain. As an example, numerical calculations are carried out for a cadmium selenide solid, and the piezoelectric effects and the effects of the electric surface charge on the thermal displacements and thermal stresses are examined precisely.

Acoustical method for the determination of the elastic and piezoelectric constants of crystals of classes 6mm and 4mm

An acoustical method is proposed for the determination of the elastic and piezoelectric constants of crystals of classes 6mm and 4mm. The method is based on the technique developed for orthorhombic crystals of class mm2 and described in the previous paper [9]. Only three samples are required for the determination of all elastic and piezoelectric constants of crystals belonging to the two symmetry classes of interest; for the crystals of class 6mm, only two samples are necessary. The proposed method can be used only when the signs of the piezoelectric constants are known beforehand. Knowing the sign of electrostriction for the crystals under study, the relative signs of the piezoelectric constants can be uniquely determined in accordance with the data reported earlier [10]. This approach allows one to extend the method used in the previous paper [9] to crystals of classes 6mm and 4mm.

Three-dimensional transient piezothermoelasticity in functionally graded rectangular plate bonded to a piezoelectric plate

In this study, the theoretical analysis of a three-dimensional transient piezothermoelasticity problem is developed for a functionally graded rectangular plate bonded to a piezoelectric plate due to partial heat supply. In this analysis, temperature distribution has a dependence on time, while the inertia term is ignored. Assuming the functionally graded rectangular plate has nonhomogeneous thermal and mechanical material properties in the thickness direction, the three-dimensional temperature in a transient state and three-dimensional transient thermal stresses of a simple supported plate for functionally graded material are analyzed by introducing the theory of laminated composites as a theoretical approximation. By using the solution for a functionally graded plate and the exact solution for piezoelectric plate of crystal class mm2, the theoretical analysis of three-dimensional transient piezothermoelasticity is developed for a simply supported combined plate. As an example, numerical calculations are carried out for a functionally graded rectangular plate made of zirconium oxide and titanium alloy, bonded to a piezoelectric plate of a cadmium selenide solid. Some numerical results for the temperature change, the displacement, the stress, electric potential, and electric displacement distributions in a transient state are shown in figures.

Control of Transient Thermoelastic Displacement of a Rectangular Composite Plate Constructed of a Cross-Ply Laminate and a Piezoelectric Material.

In this study, the theoretical analysis of a control of transient thermoelastic displacement is developed for a rectangular composite plate constructed of a cross-ply laminate and a piezoelectric material due to nonuniform heat supply. By using the exact solutions for cross-ply laminate and piezoelectric plate of crystal class mm2, the theoretical analysis of a three-dimensional transient piezothermoelasticity is developed for a simple supported combined plate. Analysis of a piezothermoelastic problem leads to an appropriate electric potential applied to the piezoelectric plate which suppresses the induced thermoelastic displacement in the thickness direction at the midpoint on the free surface of the cross-ply laminate. Some numerical results for the temperature change, the displacement, the stress in a transient state when the transient thermoelastic displacement is controlled are shown in figures.

Three-dimensional transient piezothermoelasticity for a rectangular composite plate composed of cross-ply and piezoelectric laminae

In this study, the theoretical analysis of three-dimensional transient piezothermoelasticity is developed for a rectangular composite plate composed of cross-ply laminae and piezoelectric material of crystal class mm2, subject to partial heat supply. We obtain the exact solutions for the three-dimensional temperature change in a transient state, and three-dimensional transient piezothermoelasticity of a simply supported combined plate. As an example, numerical calculations are carried out for a cross-ply laminated rectangular plate made of alumina fiber-reinforced aluminum composite, associated with a piezoelectric plate of a cadmium selenide solid. Some numerical results for temperature change, displacement, stress, electric potential, and electric displacement distributions in a transient state are shown in figures. Furthermore, the influence of thickness of the piezoelectric plate on thermal stress or electric field are investigated.