Francesco Tornabene

Università del Salento | Unisalento · Department of Engineering for Innovation

The primary focus of this study is to analyze the nonlinear vibration patterns and parametric excitation of embedded Euler–Bernoulli nanobeams subjected to thermo-magneto-mechanical loads. The Euler–Bernoulli nanobeam is developed with external parametric excitation. By utilizing nonlocal continuum theory and nonlinear von Karman beam theory, the g...

The recent design of advanced engineering components based on high-performance composites has increased the scientific attention towards accurate theoretical and computational models to simulate the mixed-mode delamination and fracturing phenomena, involving mechanical nonlinearities of materials and interfaces. In a context where fiber reinforced...

The present research applies a 2D refined plate theory and isogeometric analysis (IGA) for free vibration analysis of functionally graded (FG) sandwich plates, whose governing equations are treated based on a unified formulation (UF), and nonuniform rational Lagrange (NURL)-based IGA technique. The constitutive model of FG materials is approximated...

This work aims at studying the interfacial behavior of functionally graded coatings (FGCs) on different substrates, here modeled as asymmetric double cantilever beams, in line with the experimental tests. An enhanced beam theory (EBT) is proposed to treat the mixed-mode phenomena in such specimens, whose interface is considered as an assembly of tw...

The solution of the nonlinear (NL) vibration problem of the interaction of laminated plates made of exponentially graded orthotropic layers (EGOLs) with elastic foundations within the Kirchhoff–Love theory (KLT) is developed using the modified Lindstedt–Poincaré method for the first time. Young’s modulus and the material density of the orthotropic...

The present research aims at determining the axial buckling load of stiffened multilayer cylindrical shell panels made of functionally graded graphene-reinforced composites (FG-GPL RCs). Rings and stringers are applied as stiffening tools for shell panels, whose elastic properties are determined according to the Halpin–Tsai relations. The virtual w...

The manuscript presents an efficient semi-analytical solution with three-dimensional capabilities for the evaluation of the static response of laminated curved structures subjected to general external loads. A two-dimensional model is presented based on the Equivalent Single Layer (ESL) approach, where the displacement field components are describe...

This study investigates the sensitivity of dynamic properties in coupled curved beams reinforced with carbon nanotubes (CNTs) to thermal variations. Temperature-dependent (TD) mechanical properties are considered for poly methyl methacrylate (PMMA) to be strengthened with single-walled CNTs (SWCNTs), employing the basic rule of mixture to define th...

Adopting an effective layup sequence in laminated composite structures has always compelled scientists to investigate the behavior of laminated composite constructions. The present article presents the buckling analysis of double-and cross-helicoidal laminated composite plates using recently proposed HOZT. The Buckling behavior of helicoidal plates...

In the present work, a refined theory with three-dimensional capabilities is proposed for the structural analysis of shell structures made of smart materials for advanced engineering applications. Principal curvilinear coordinates are used for the geometry definition of the structure. The kinematic description of the configuration variables is perf...

The main aim of this book is to analyze the mathematical fundamentals and the main features of the Generalized Differential Quadrature (GDQ) and Generalized Integral Quadrature (GIQ) techniques. Furthermore, another interesting aim of the present book is to shown that from the two numerical techniques mentioned above it is possible to derive two di...

This book aims to present in depth several Higher-order Shear Deformation Theories (HSDTs) by means of a unified approach for studying the Hygro-Thermo-Magneto-Electro-Elastic Theory of Anisotropic Doubly-Curved Shells. In particular, a general coupled multifield theory regarding anisotropic shell structures is provided. The three-dimensional multi...

The large demand of reinforcement systems for the rehabilitation of existing concrete and masonry structures, has recently increased the development of innovative methods and advanced systems where the structural mass and weight are reduced, possibly avoiding steel reinforcements, while using non-invasive and reversible reinforcements made of pre-i...

The work focuses on the post- buckling behavior of functionally graded graphene platelet (FG-GPL)-reinforced porous thick rings with open-cell internal cavities under a uniform external pressure. The generalized rule of mixture and the modified Halpin–Tsai model are here used to evaluate the effective mechanical properties of the ring. Three types...

In a context where daily and seasonal temperature changes or potential fire exposure can affect the mechanical response of structures strengthened with fiber-reinforced polymer (FRP) composites during their life cycle, the present work studies the bond behavior of FRP laminates glued to concrete substrates under a thermal variation. The problem is...

The present investigation has analyzed the buckling of bi-directional functionally graded conical micro-shells bearing axial loading. The dominant equations serve on the basis of the theory of first-order shear deformation in the modified couple stress theory (MCST). The Ritz technique is used so as to solve the governing equations. Bi-directional...

We investigated the thermal buckling temperature and nonlinear free vibration of functionally graded fiber-reinforced composite laminated (FG-FRCL) beams. The governing nonlinear partial differential equations were derived from the Euler–Bernoulli beam theory, accounting for the von Kármán geometrical nonlinearity. Such equations were then reduced...

In this work, the state -space nonlocal strain gradient theory is used for the vibration analysis of magneto thermo piezoelectric functionally graded material (FGM) nanobeam. An analysis of FGM constituent properties is stated by using the power law relations. The refined higher order beam theory and Hamilton’s principle have been used to obtain th...

In the present contribution a general formulation is proposed to account for general boundary conditions within the dynamic analysis of anisotropic laminated doubly-curved shell having arbitrary shape and variable thickness. Different analytical expressions are considered for the shell thickness variation along the geometrical principal directions,...

The buckling response of functionally graded (FG) porous spherical caps reinforced by graphene platelets (GPLs) is assessed here, including both symmetric and uniform porosity patterns in the metal matrix, together with five different GPL distributions. The Halpin–Tsai model is here applied, together with an extended rule of mixture to determine th...

In the present work, a two-dimensional model based on a higher order Layer-Wise (LW) approach is presented for the static and dynamic analysis of doubly-curved anisotropic shell structures. The Equivalent Single Layer (ESL) methodology is also obtained as particular case of LW. Each lamina of the stacking sequence is modelled as an anisotropic cont...

This paper presents a hyperbolic shear deformation theory and discusses its application to investigate the bending and buckling behavior of functionally graded carbon nanotubes-reinforced composite (FGCNTRC) beams. The proposed theory satisfies the parabolic variation of shear stress distribution throughout the thickness and fulfills the zero condi...

PurposeThis work deals with the time-deflection responses of functionally graded (FG) porous plates and spherical shells subjected to different external pulse excitations by means of an improved first order shear deformation theory (Im-FSDT) with improved transverse shear deformations.Methods Here a quadratic function is considered to allow for a p...

We address the nonlinear free vibration, superharmonic and subharmonic resonance response of homogenous Euler–Bernoulli beams resting on nonlinear viscoelastic foundations, under a moving mass and an abrupt uniform temperature rise. The nonlinear differential equation of motion stemming from the Hamiltonian principle and Finite Strain Theory is dis...

The vibration behavior of porous nano-composite Assembled Paraboloidal-Cylindrical Shell (APCS) structures is evaluated in the present study. In detail, Graphene Oxide Powder (GOP) nanomaterials are served to improve the mechanical features correlated with porous polymer and metal matrices in order to build a Hybrid Polymer Matrix (HPM) and Hybrid...

The present article studies the two phase local/nonlocal deformation of thermo electrical composite nanobeam reinforced with graphene oxide powder (GOP). The controlling equation of motion and boundary conditions are derived via two phase elasticity in differential form in conjunction with Hamilton's principle and Euler‐Bernoulli beam theory. The e...

The present work aims at investigating the hygrothermal effect on the natural frequencies of functionally graded (FG) annular plates integrated with piezo-magneto-electro-elastic layers resting on a Pasternak elastic foundation. The formulation is based on a layer-wise (LW) theory, where the Hamiltonian principle is used to obtain the governing equ...

In this paper, a new analytical approach to the nonlinear analysis of functionally graded graphene platelet reinforced composite (FG-GPLRC) laminated cylindrical shells under external pressure and thermal environment is presented for the first time. The analytical approach is based on the higher-order shear deformation theory (HSDT), which is enric...

This work studies the buckling and free vibration behavior of Shape Memory Alloy Hybrid Composite (SMAHC) sandwich beams under a thermal environment. The sandwich beams consist of layers reinforced with SMAs and a FGM core, and they are simply supported at both ends. The higher order theory is combined with the Minimum Potential Energy principle or...

The fracturing process in geomaterials is studied to characterize a potential host rock for radioactive waste, such as the kaolinite-rich Opalinus Clay formation. Because of its sedimentary genesis, this rock can be considered as a transversely isotropic geomaterial. A semi-circular bending test is here modeled based on the eXtended Finite Element...

In the presentmanuscript, a Layer-Wise (LW) generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface loads. The unknown field variable is modelled employing polynomials of various orders, each of them defined within each layer of t...

The article proposes an Equivalent Single Layer (ESL) formulation for the linear static analysis of arbitrarily-shaped shell structures subjected to general surface loads and boundary conditions. A parametrization of the physical domain is provided by employing a set of curvilinear principal coordinates. The generalized blending methodology account...

The present work investigates the modal response of doubly-curved shells characterized by unsymmetric lamination schemes embedding anisotropic materials and externally constrained with general boundary conditions along the edges. The Equivalent Single Layer (ESL) methodology has been adopted for the assessment of the fundamental governing equations...

The increased requirements in design and manufacturing nanotechnology have favored the development of enhanced composite materials with tailored properties, such as functionally graded (FG) and carbon-based materials, primarily carbon nanotubes (CNTs), and graphene sheets or nanoplatelets, because of their remarkable mechanical properties, electric...

Laminated doubly-curved shells constituted by innovative materials have become a standard application in several engineering fields. However, this requires a proper formulation of such structures, since several very complex issues affecting such applications must be kept in mind, among all, the curvature effect and the coupling issues between two a...

The advancement in manufacturing technology and scientific research have improved the development of enhanced composite materials with tailored properties depending on their design requirements in many engineering fields, as well as in thermal and energy management [...]

In the present work a novel approach is presented for the modal analysis of shells with arbitrary geometry, general boundary conditions and variable thickness. The Equivalent Single Layer (ESL) methodology is followed for the definition of the fundamental set of equations. Shell reference surface is defined with respect to a proper curvilinear coor...

The paper focuses on a bi-dimensional (2D) formulation for the dynamic and static analysis of arbitrary shaped laminated doubly-curved shells enforced with general boundary conditions via the Generalized Differential Quadrature (GDQ). Following the Equivalent Single Layer approach, a 2D theory based on a miscellaneous assessment of the displacement...

The present work studies an axisymmetric rotating truncated cone made of functionally graded (FG) porous materials reinforced by graphene platelets (GPLs) under a thermal loading. The problem is tackled theoretically based on a classical linear thermoelasticity approach. The truncated cone consists of a layered material with a uniform or non-unifor...

This work deals with the wave propagation analysis in functionally graded carbon nanotubes (CNTs)-reinforced composite beams lying on an elastic medium. Despite the large amount of experimental and theoretical studies in the literature on the mechanical behavior of composite structures strengthened with CNTs, limited attention has been paid to the...

A numerical modeling based on Higher-order Shear Deformation Theories (HSDTs) is here proposed to compute the fundamental frequency of composite anisogrid panels and shells, as typically encountered in large-span buildings or aerospace structures, due to their outstanding properties of transparency and lightness. An anisotropic homogenized continuu...

A new higher-order shear deformation zig-zag theory enriched by polyconvex strain cover functions is proposed for predicting the nonlinear stability characteristics of thermo mechanically loaded carbon nanotube-reinforced composite (CNTRC) laminated cylindrical shells surrounded by elastic foundations. The thermomechanical properties of composite l...

This work studies the size-dependent free vibration response of functionally graded (FG) nanoplates using a layerwise theory. The proposed model supposes not only a higher-order displacement field for the core but also the first-order displacement field for the two face sheets, thereby maintaining an interlaminar displacement continuity among layer...

Nonlinear dynamic analysis of FG/SMA/FG sandwich shells on elastic foundations subjected to the thermomechanical loading is performed in this paper for the first time. The sandwich shells are made of a shape memory alloy (SMA) fiber-reinforced composite and functionally graded (FG) face sheets. Material properties of FGM shells are assumed to be te...

In the present work, a novel analytical model is provided for wave dispersion in a piezo-thermoelastic diffusive functionally graded rod through the multi-phase lag model and thermal activation. The plain strain model for thermo piezoelectric functionally graded rod is considered. The complex characteristic equations are obtained by using normal mo...

In the present paper, a composite finite element is proposed using the assumed natural strain (ANS) method, which is based on the unified strain interpolations and the minimized potential energy. In the proposed formulation, the linearized weak form of compatibility and equilibrium equations is obtained for the geometrically nonlinear analysis. Add...

An innovative generalized Layer-Wise (LW) approach is proposed for the modal analysis of anisotropic doubly-curved shells with an arbitrary shape by employing the Generalized Differential Quadrature (GDQ) method. The geometrical description of shell structures can be traced from both the differential geometry and mapping technique based on a proper...

The present article deals with the computation of natural frequencies of 3D fibre-reinforced anisotropic laminated composite and soft-core sandwich beams by using a 1D Ritz–Jacobi formulation. Generalised higher-order beam models, based on both 2D Taylor and 2D Chebyshev polynomials, are employed in the investigation. The weak-form of the governing...

The present work analyzes the free vibration response of functionally graded (FG) plates made of Aluminum (Al) and Alumina (Al2O3) with different porosity distributions, as usually induced by a manufacturing process. The problem is tackled theoretically based on a higher-order shear deformation plate theory, while proposing a Navier-type approximat...

The present work studies the buckling behavior of functionally graded (FG) porous rectangular plates subjected to different loading conditions. Three different porosity distributions are assumed throughout the thickness, namely, a nonlinear symmetric, a nonlinear asymmetric and a uniform distribution. A novel approach is proposed here based on a co...

This paper studies the fracturing process in geomaterials in order to define the mechanical properties of elements belonging to the lithosphere, such as the kaolonite-rich Opalinus Clay (OPA) formation, due to its potential application as host rock for radioactive waste. For the sedimentary genesis, this rock can be considered a transversely isotro...

Due to the widespread use of sandwich structures in many industries and the importance of understanding their mechanical behavior, this paper studies the thermomechanical buckling behavior of sandwich beams with a functionally graded material (FGM) middle layer and two composite external layers. Both composite skins are made of Poly(methyl methacry...

Aim and Scope In today's challenging world, Civil engineering is regarded as one of the most important engineering fields across the globe. Since the biggest challenges are facing the world today include: High building energy consumption; Crude estimation of sea level; Increased soil and coastal erosion; Inadequate water quality; Untapped and depl...

A new multi-step optimization method is developed to predict the optimal fiber orientation in glass fiber reinforced polymer (GFRP) composite shells. The method contains 1) a regenerated genetic algorithm (GA) optimization strategy coupled with, 2) an analytical approach regarding assessing the failure of the tubular structure. Two critical factors...

In this work, we discuss the free vibration behavior of thin-walled composite shell structures reinforced with carbon nanotubes (CNTs) in a nonlinear setting and resting on a Winkler–Pasternak Foundation (WPF). The theoretical model and the differential equations associated with the problem account for different distributions of CNTs (with uniform...

This paper addresses the flexural–torsional stability of functionally graded (FG) nonlocal thin-walled beam-columns with a tapered I-section. The material composition is assumed to vary continuously in the longitudinal direction based on a power-law distribution. Possible small-scale effects are included within the formulation according to the Erin...

In this work, we study the vibration and bending response of functionally graded graphene platelets reinforced composite (FG-GPLRC) rectangular plates embedded on different substrates and thermal conditions. The governing equations of the problem along with boundary conditions are determined by employing the minimum total potential energy and Hamil...