A.A. Aljinaidi

Micromechanical modeling of magnetoelectroelastic composite materials with multicoated inclusions and functionally graded interphases

In this article, micromechanical modeling of magnetoelectroelastic composites with multicoated inclusions and functionally graded interphases are elaborated. The integral equation taking into account the continuously varying interphase properties as well as the multifunctional coating effects is introduced based on Green’s tensors and interfacial operators. Magnetoelectroelastic composites with functionally graded interphases are analyzed, and the effective properties are derived. Based on the Mori–Tanaka, Self-Consistent, and Incremental Self-Consistent models, the numerically predicted effective properties of magnetoelectroelastic composites are presented with respect to the volume fractions, shapes of the multicoated inclusions, and the thickness of the coatings. The multicoating and functionally graded interphase concepts can be used to optimize the effective properties of multifunctional composites. This can be used to design new multifunctional composite materials with higher coupling coefficients.

Viscomagnetoelectroelastic effective properties’ modeling for multi-phase and multi-coated magnetoelectroelastic composites

In this article, the effective properties of new active–passive multifunctional viscomagnetoelectroelastic composite materials are modeled and numerically predicted. The correspondence principle, extended to linear viscomagnetoelectroelasticity, and the Carson transform are coupled to the Mori–Tanaka micromechanical mean field approach. Based on the viscomagnetoelectroelastic convolution integral equations and the interfacial operators, the concentration tensors are derived for multi-phase and multi-coated viscomagnetoelectroelastic composites. The effective properties are derived in the frequency domain and then inverted numerically to the time domain using the inverse transform. The effective properties are thus obtained in both frequency and time domains. The obtained hybrid multifunctional coefficients can be used for their active and passive properties. The resulting visco-magneto-electro-elastic effects can be enhanced by a proper choice of the shape and volume fraction of reinforcements as well as by coating thickness.

Dynamic analysis of Carbon NanoTubes conveying fluid with uncertain parameters and random excitation

ABSTRACT Methodological approaches based on the nonlocal beam theory, differential quadrature and internal random coefficients methods are elaborated for parameters uncertainty effects on the dynamic behavior of viscoelastic Carbon NanoTubes (CNT) conveying viscous fluid. The general polynomial chaos and the superposition principle are used and several random parameters that may follow various distribution laws are considered. A selecting procedure of the most influencing random parameters on the dynamic behavior of CNT is given. The space and multimodal time domains are formulated and frequency and time responses are investigated. Effects of various random parameters on free and forced random vibrations are investigated.

Analytical and semi-analytical modeling of effective moduli bounds: Application to transversely isotropic piezoelectric materials

In this article, analytical and semi-analytical models of upper and lower bounds for the effective moduli of transversely isotropic piezoelectric heterogeneous materials based on the generalized Hashin–Shtrikman variational principle are presented. Compact matrix formulations are used to derive closed-form bound expressions for coupled and uncoupled effective moduli. Analytical models are given for some uncoupled coefficients and simplified formulations for the others. For more narrow bounds, downstream and upstream bounds are developed based on an incremental procedure. Numerical predictions are performed based on the developed methodological approaches, and the obtained results showed the applicability and effectiveness of the proposed models for transversely isotropic elastic and piezoelectric composite materials with ellipsoidal reinforcements of different types and shapes.