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Dislocation behavior is a critical feature in describing the reliable properties of structures and materials. As a new kind of smart material, multiferroic solids have special applications on the coupling systems of mechanical, electric, and magnetic fields. Then, the moving dislocation in multiferroic solids has special interests for strength characteristics. In the present work, the moving edge dislocation is studied by the eigenstrain theory. The explicit solutions are derived and can be reduced to the piezoelectric and even pure elastic materials as the special cases. [ABSTRACT FROM PUBLISHER]

A screw dislocation in a functionally graded magnetoelectroelastic material is investigated. The material properties exponentially changing along bothxandydirections are considered and the mechanical–electric–magnetic coupling is discussed. Closed-form expressions for the mechanical, electric and magnetic components are derived using the general stress function method. The solutions can be applied as a fundamental result and reduced into the classic and piezoelectric cases. The study puts forth a direct way for screw dislocation analysis in inhomogeneous structures with multifield coupling. [ABSTRACT FROM AUTHOR]

Considering the effects of nonlinear damping, the vibration stability of the parametrically excited piezoelectric beams is studied. The Hamilton principle is applied to derive the equation of motion and the method of multiple scales is tied to solve the amplitude values of the stationary response. The numerical example is given to analyze the effects of the voltage, axial force and nonlinear damping on the stability of the steady solution. From the results that the difference ΔV between the applied Outer voltage and the electric potential deference between the upper and lower surfaces of the piezoelectric layer mainly affects the range of the independent variable σ/ω and has slight effects on the stability of the steady solution; the smaller the axial force, the larger the stable regions of the steady solution; and the larger the constant and quadratic terms of the nonlinear damping, the larger the stable regions of the steady solution. [ABSTRACT FROM AUTHOR]

In this investigation, the non-reciprocal transmission in a nonlinear elastic metamaterial with imperfect interfaces is studied. Based on the Bloch theorem and stiffness matrix method, the band gaps and transmission coefficients with imperfect interfaces are obtained for the fundamental and double frequency cases. The interfacial influences on the transmission behaviour are discussed for both the nonlinear phononic crystal and elastic metamaterial. Numerical results for the imperfect interface structure are compared with those for the perfect one. Furthermore, experiments are performed to support the theoretical analysis. The present research is expected to be helpful to design tunable devices with the non-reciprocal transmission and diode behaviour of the elastic metamaterial., Competing Interests: We declare we have no competing interests., (© 2021 The Author(s).)

The nonlinear dynamical equations are established for the double layered viscoelastic nanoplates (DLNP) subjected to in-plane excitation based on the nonlocal theory and von Kármán large deformation theory. The extended high dimensional homoclinic Melnikov method is employed to study the homoclinic phenomena and chaotic motions for the parametrically excited DLNP system. The criteria for the homoclinic transverse intersection for both the asynchronous and synchronous buckling cases are proposed. Lyapunov exponents and phase portraits are obtained to verify the Melnikov-type analysis. The influences of structural parameters on the transverse homoclinic orbits and homoclinic bifurcation sets are discussed for the two buckling cases. Some novel phenomena are observed in the investigation. It should be noticed that the nonlocal effect on the homoclinic behaviors and chaotic motions is quite remarkable. Hence, the small scale effect should be taken into account for homoclinic and chaotic analysis for nanostructures. It is significant that the nonlocal effect on the homoclinic phenomena for the asynchronous buckling case is quite different from that for the synchronous buckling case. Moreover, due to the van der Walls interaction between the layers, the nonlocal effect on the homoclinic behaviors and chaotic motions for high order mode is rather tiny under the asynchronous buckling condition.