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• The theoretical forms of wavenumber of transverse surface waves in orthotropic piezoelectric media are acquired with extended stroh formalism. • The phase velocity equation of transverse surface wave propagation in the orthotropic and transversely isotropic layers overlying an isotropic elastic dielectric semi-space is obtained. • A physical model for depicting the bulk and surface layers' horizontal shear stiffness versus the orientation of wave propagation is established. • A numerically comparable study is carried out on phase velocity and shear stiffness versus wave propagation directions. Previous works on surface acoustic wave sensors have shown great limitations in selecting piezoelectric materials and the wave propagation direction. To eliminate such limitations in the technological revolution of SAW sensors, the current paper's main purpose is to explore how wave propagation orientation affects the performance of SAW macro- and nano-sensors. Based on Extended Stroh formalism, the theoretical forms are derived and exploited to present the wavenumber of transverse waves in an arbitrary direction of the piezoelectric medium. Furthermore, we consider surface elasticity theory to acquire the phase velocity equation on the basis of the expression of the wavenumber. More intuitively, a physical model is set up to obtain the horizontal shear stiffness of the surface and bulk layers. Then, the numerical case is carried out to determine the relationship between phase velocity and wave propagation orientation. By comparing the numerical study and the physical model, it can be found that the empirical formula of shear stiffness for bulk and surface layers offers a helpful route to precisely predict the mechanical attributes of SAW macro- and nano-sensors, respectively. The summaries of the current theoretical work benefit the manufacturing of surface acoustic wave sensors with improved performance. [ABSTRACT FROM AUTHOR]

This paper aims to present novel exact solutions for the buckling of a laminated plate resting on the viscoelastic foundation with both normal and shear viscoelastic layers. The governing equations of plate buckling are derived using three-dimensional elasticity theory and state-space formulation. The normal and shear layers of the viscoelastic foundations are modeled using the generalized Maxwell model to represent both the elastic and viscose properties of the foundation. To couple the viscoelastic foundation equation with the buckling equation, Boltzmann's superposition principle along with the Laplace transform is utilized. Then, the effects of geometry, relaxation modulus of normal and shear layers, viscosity, and time are investigated on the buckling load. The results reveal that the higher viscosity coefficient leads to a slower rate of change in the buckling loads. In addition, the viscoelastic properties have a significant impact on the buckling behavior of the plate. In this regard, the results show that instead of the expected second mode at a constant aspect ratio, the plate experiences the first mode as time passes. The computed results also show that there is a critical threshold. When the foundation stiffness exceeds this threshold, the conventional method of reducing the aspect ratio to prevent buckling not only proves ineffective in reducing the probability of buckling but also, in fact, leads to an increase in buckling occurrences. In addition to the analytical investigation, a finite element (FE) analysis is carried out to study the buckling response of the composite plate. The finite element results also show a reasonably good agreement with those of the analytical method. • Exact solution for plate buckling on foundation with normal and shear layers. • The effects of viscoelastic spring and dashpot constants on buckling load is studied. • The buckling equations are derived by using the three-dimensional elasticity theory. • Boltzmann's principle and Laplace transform link viscoelastic foundation to buckling. [ABSTRACT FROM AUTHOR]

• 2D and 3D multi-material lattices were designed and manufactured. • Analytical models were modified to be applicable to the multi-material lattices. • Homogenization-based models were applied to the designed lattices. • A comparison was conducted between the developed models, FEA, and experiment. • Anisotropy of the 3D lattice was studied with different material arrangements. Advances in multi-material additive manufacturing have opened unprecedented new opportunities for the design and manufacture of lightweight multifunctional structures. The ability to create complex topologies, at a relatively fine resolution, in addition to controlling the material composition on a voxel basis have significantly expanded the design space. To explore this large design space efficiently, accurate and cost-effective modeling tools are essential. In this paper, mechanics-based models for predicting the elastic properties of multi-material 2D and 3D lattice structures are developed or extended. The outcomes are compared with the predictions obtained from finite element models and experimental data. The results reveal that the adapted analytical models demonstrate good accuracy in predicting the elastic modulus of multi-material lattices for relative densities up to approximately 25 % while have considerably less computational cost compared to finite element using solid elements (providing the most accurate results in comparison with experiment). Careful consideration of the accuracy of the predictions is necessary for the use of these models for lattices with high relative density values. Besides, several homogenization-based models were studied to investigate their applicability to multi-material lattice structures when the assumption of scale-separation is considered valid. The capability of these models in predicting the whole elasticity tensor and the potential of multi-material lattices in manipulating the anisotropy are demonstrated. Finally, the introduced prediction frameworks are compared in order to provide an overview of their respective advantages and disadvantages in the case of multi-material lattice structures. [Display omitted] [ABSTRACT FROM AUTHOR]

To apply the Direct Strength Method (DSM) to web crippling of lipped channel sections, experiments were recently conducted under EOF and IOF loading conditions. In the research presented here, finite element models were first developed to predict the elastic buckling loads and the elasto-plastic behaviour, both of the experiments and an extended data set. New first- and second-order elasto-plastic theoretical models describing the plastic mechanism initiation of a 2D cross-sectional strip of the lipped channel sections were then developed. Subsequently these 2D cross-sectional models were transformed to full 3D models by using modelled yield line patterns as observed in the finite element simulations. Both the first- and second-order 3D models correlate well with the full section simulations. DSM equations were calibrated based on the results from the simulations, using several alternatives for the yield load as needed in the DSM: a first yield load from the finite element simulations; a rigid-plastic mechanism initiation load as used by other researchers; and a first-order elasto-plastic mechanism initiation load via the above theoretical models. Finally, these calibrated DSM equations were compared with the theoretical models, design codes, and a basic Merchant-Rankine approach. For the DSM, the first order rigid-plastic yield load, most appropriate for the DSM and used by other researchers also, performs best for IOF load cases. For EOF load cases, however, using the first-order elasto-plastic load in the DSM gives best results. Taking these different yield loads for the different cases then, the DSM outperforms Eurocode, AISI S100, and the basic Merchant Rankine predictions. The DSM is intuitively and relatively easy to use, and this paper shows that widening its scope to web crippling of lipped channel sections is possible. Importantly, this paper steps into the discussion for a certain type of yield load to be used in the DSM for web crippling, and gives several arguments to consider the rigid-plastic mechanism initiation load. [ABSTRACT FROM AUTHOR]

The paper focuses on thermal torsional post buckling of functionally graded carbon nanotube reinforced composite cylindrical shells with sur-bonding piezoelectric layers and embedded in an elastic medium. The distribution of reinforcements through the thickness of the shells is considered to be uniform and functionally graded. The basic equations using geometrically nonlinearity in von Karman-Donnell sense within the classical thin shell theory are established. The torsional post-buckling behavior of the piezoelectric functionally graded carbon nanotubes reinforced composite (FG-CNTRC) shells is analyzed with using the Airy's stress function and the Galerkin's method, in which a three-term approximate solution of the deflection of the shell is assumed. Effects of thermal environment, CNT volume fraction, piezoelectric layers (the thickness and the constant voltage), distribution type of the reinforcement, dimensional parameters and Winkler and Pasternak foundation are investigated in this paper. Numerical and graphical results show that the carbon nanotube volume fraction and the piezoelectric layers as well as the elastic foundation and the thermal loads have significantly influenced on the torsional postbuckling behavior of nanocomposite shells. [ABSTRACT FROM AUTHOR]

• Multifield analysis of doubly-curved shell structures • Coupling between the mechanical elasticity and the thermo-hygrometric problem. • Coupling between the mechanical elasticity and the magneto-electricity problem. • Generalized formulation based on the Equivalent Layer Wise approach. • Recovery of primary and secondary variables from the 3D multifield balance equations. The paper presents a multifield formulation involving five different physical problems under the equilibrium thermodynamic conditions for laminated doubly-curved shell structures. More specifically, the study focuses on the coupling between the mechanical elasticity and the thermo-hygrometric problem, while also considering the magneto-electricity of the solid. The configuration variables are described with a generalized formulation based on the Equivalent Layer Wise (ELW) approach, taking into account higher order polynomial interpolations along the thickness direction. The fundamental relations are derived from the Master Balance principle and solved using the Navier's method. Furthermore, the three-dimensional response of the doubly-curved shell solid in terms of primary and secondary variables is recovered from the two-dimensional solution with a methodology based on the three-dimensional multifield balance equations and the Generalized Differential Quadrature (GDQ) numerical technique. Some examples are then presented in which panels of different curvatures and lamination schemes are investigated. The results are compared with success to those coming from three-dimensional numerical models developed with a commercial software. It is shown that the present analytical solution is a valid tool for modelling multifield problems for the evaluation of the response of doubly-curved shells under generalized external actions and pre-determined values of the configuration variables. [ABSTRACT FROM AUTHOR]

The snap fit is a commonly used jointing/connection mechanism because it is simple and reusable, and its easy installation and difficult removal are the result of the coordinated interaction between friction, geometric shape, and elasticity. This paper presents a detailed study on the assembly/disassembly forces of thin-walled torus snap-fit through finite element simulation, experimental testing, and data fitting of approximate analytical solutions. The research reveals that the non-zero Gaussian curvature of the torus has a significant impact on the mechanical performance of the torus snap fit. The findings in this study are of great significance for future design of high-performance structural connections. • Studied the segmental torus snap fit assembly/disassembly mechanics for the first time. • Carried out FEM analysis on assembly/disassembly process. • Conducted experiments on assembly/disassembly process. • Proposed approximate analytical assembly/disassembly force. [ABSTRACT FROM AUTHOR]

• A new type of lattice cylindrical shell meta-structure with broadband vibration reduction and high load-bearing ability is designed and fabricated. • The dispersion relation of the meta-structure with curvature is obtained through coordinate transformation. • The meta-structure can maintain certain broadband vibration reduction properties when increasing the load-bearing capacity by changing the structural parameters. In this paper, a new type of lattice cylindrical shell meta-structure (LCSM) with broadband vibration reduction and high load-bearing ability is designed. In particular, the proposed curved shell meta-structure is constructed by combining lattice structure and mechanical metamaterial with elastic bandgap properties. The dispersion curves of shell structure are obtained by combining Bloch's theorem with the coordinate transformation method. The vibration transmission properties and load-bearing performance of the LCSM and the sandwich LCSM are studied numerically and experimentally. The results reveal that the proposed meta-structure has excellent vibration isolation performance at broadband frequencies, and the change of structural parameters can be used to regulate the frequency range of bandgap. Especially, the existence of curvature makes the bandgap of the shell structure inevitably change when the circumferential size of the shell is changed. Moreover, the meta-structure can maintain certain broadband vibration reduction properties when increasing the load-bearing capacity. This work offers an innovative method to develop multi-functional lattice shell structures with both load-bearing and broadband vibration isolation properties. [ABSTRACT FROM AUTHOR]

In the paper the buckling of simply supported plates under combined bending, shear and patch loading is studied in this paper with ANSYS, such a stress state occurs in girder supporting over-head crane. The effect of the width-to-height ratio of the plate and the width of patch loading on the interactive curves are analyzed in detail. And, it is found that the effect of the width of patch loading on the nondimensional interaction curves of bending and patch loading and the interactive curves of shear and patch loading is small. Through detailed FEM analysis, the interaction curves between any two among three stress components are obtained, and then through a designed numerical strategy the nondimensional 3D interactive surfaces of bending, shear and patching loading is found. An approximate equation for the 3D surface is proposed, comparison with the FE results shows that the proposed formula has excellent accuracy. [ABSTRACT FROM AUTHOR]

Thermal gradients often occur in fire exposed structures. This paper considers thermal gradients over the cross-section of steel columns. By means of finite element simulations, the paper demonstrates that these gradients reduce the flexural buckling resistance of the columns. This is due to the eccentricity in the column created by the temperature gradient. Design equations in modern standards provide a gross approximation of the load bearing resistance of such columns in which the eccentricity is ignored and in order to compensate for this the yield stress and modulus of elasticity are to be determined at maximum temperature. Based on an in-depth analysis of the results of the finite element simulations, this paper provides an alternative design model which much better agrees with the actual behaviour of a fire exposed column. [ABSTRACT FROM AUTHOR]

This paper presents a finite strip program CUFSM used to calculate and analyze the elastic distortional buckling of cold-formed thin-walled steel flexural members with stiffeners in the flange, which has different sectional geometric parameters. According to the classical buckling stress formula, the distortional buckling coefficient of the flange can be calculated so as to analyze the influence of changed sectional geometric parameters on it. On this basis, this study provides a simplified formula of distortional buckling stress to calculate 40 members with different sections which are selected from the Technical Code of Cold-Formed Thin-Wall Steel Structures of China but not contained in this paper. Compared with the analysis results of CUFSM, it shows that the two simplified formulas have quite high accuracy and wide applicability for general members provided by the specification. So it is suggested that they can be used for engineering design and standard revision. [ABSTRACT FROM AUTHOR]

Industrial steel storage pallet racks are quite similar to the framed steelworks traditionally used for civil and commercial buildings: great differences are due to both the presence of boltless beam-to-column connections and to the very extensive use of thin-walled cold-formed members. Serviceability response as well as ultimate limit conditions are quite complex to predict; high engineering competences are required to guarantee significant load carrying capacities with structural systems of extremely limited weight, and, as a consequence, of very modest costs to be competitive on the market. Design standards have been recently updated worldwide; with reference to the European practice, different alternatives are now offered to designers: from the selection of the method of analysis to the approaches for the serviceability, resistance and buckling checks of the whole racks as well as of its main components. The design paths admitted by the Codes correspond to different values of the structural performances guaranteed by racks, or equivalently, to significantly different costs. A two-parts paper has been written to summarize the first research outcomes of a study on the static design rules currently adopted in Europe for steel storage pallet racks. In particular, a parametric numerical analysis has been developed on medium-rise racks of different configurations, member geometries and rotational stiffness of both beam-to-column and base-plate connections. A wide range of cases of practical interest, comprising of mono- and bi-symmetric cross-sections used for uprights, has been analyzed by means of an open source finite element program for academic use, improved by authors with a suitable beam formulation accounting for main warping effects. The present part 1 deals with the selection of the method of analysis, i.e. 1st or 2nd order elastic analysis, depending on the rack deformability to horizontal loads. Internal forces and moments on members are significantly influenced by the effects of lateral displacements as well as by the type of the beam formulation adopted in the finite element analysis program. In the following, different design alternatives are discussed: the use of the overall buckling analysis, a classical approximate method and few theoretical approaches. The rules for the resistance and stability checks of beam-column members under static loading are discussed in part 2 (“Essential Verification Checks”) of this two-parts paper, together with a critical analysis of the influence of warping effects on the serviceability limit state for lateral deflection of the whole racks. [ABSTRACT FROM AUTHOR]

Classical piezomagnetic elasticity theory fails to explain the size-dependent magneto-mechanical behaviour. The extended piezomagnetic elasticity theory incorporating the strain gradient elasticity and flexomagneticity is developed to describe the size effects phenomenon. Compared with the flexomagneticity whose contribution is explicit, the influence mechanism of strain gradient elasticity on the magneto-mechanical response is not clarified. In this paper, we clarify the relation and difference among the extended piezomagnetic elasticity theory considering different strain gradient elasticity. For the relation analysis, according to the orthogonal decomposition of the general strain gradient elasticity, we express the extended piezomagnetic elasticity theory in form of strain gradient tensor and its components of symmetric/anti-symmetric splitting, respectively. By ignoring some strain gradients, the extended piezomagnetic elasticity theory with the general strain gradient elasticity can reduce to that with the reduced strain gradient elasticity. For the difference analysis, we perform the magneto-mechanical analysis of the Terfenol-D/Silicon bilayer microbeam. The flexomagnetic coefficient of Terfenol-D is obtained by fitting deflection solution with experiment results. Then, the size-dependent direct/inverse magneto-mechanical behaviour is revealed. Results reveal that the strain gradient effects and flexomagnetic effects significantly affect the magnetic potential and bending defection when the beam thickness is comparable to the material length-scale parameters. Moreover, compared with the extended piezomagnetic elasticity theory with the reduced strain gradient elasticity, the extended piezomagnetic elasticity theory with the general strain gradient elasticity predicts smaller magnetic potential, bending deflection, and thus can describe the magneto-mechanical behaviour more appropriately. • The relation among the general/reformulated/dilatation strain gradient elasticity is studied. • The difference of the extended piezomagnetic elasticity theories in describing the size dependency is revealed. • The fitting value of flexomagnetic efficient of Terfenol-D is obtained. • The direct/inverse magneto-mechanical problems are solved. • The contributions from the strain gradient effects and flexomagnetic effects are identified, respectively. [ABSTRACT FROM AUTHOR]

Abstract Delamination is the most severe damage in drilling of composite laminates. Using the backup plate is an appropriate method to control drilling induced delamination. In this paper, an analytical model is applied to determine the critical thrust force and the feed rate for drilling of composite laminates with backup plate. To achieve this aim, the classical laminate plate theory (CLPT), the linear elastic fracture mechanic (LEFM) and the oblique cutting model are used. In analytical models, two separate distributed loads have been exerted by cutting and chisel edges. Based on the model results, the effect of the drill diameter, the chisel edge size, and the backup plate size, on the critical thrust force and the feed rate are investigated. Experimental tests are carried out to prove the analytical model. Highlights • Effect of backup plate in drilling of composite laminate has been studied. • Analytical model based on CLPT, LEFM and oblique cutting has developed. • Effect of chisel edge, backup, delamination area and drill size has considered. • 8 experiments with 4 feed rates in with and without backup has done. • Good agreement between analytical and experimental results, error less than 26%. [ABSTRACT FROM AUTHOR]

The in-plane mechanics of two-dimensional heterogeneous hexagonal lattices are investigated. The heterogeneity originates from two physically realistic considerations: different constituent materials and different wall thicknesses. Through the combination of multi-material and multi-thickness elements, the most general form of 2D heterogeneous hexagonal lattices is proposed in this paper. By exploiting the mechanics of a unit cell with multi-material and multi-thickness characteristics, exact closed-form analytical expressions of equivalent elastic properties of the general heterogeneous lattice have been derived. The equivalent elastic properties of the 2D heterogeneous lattice are Young's modulli and Poisson's ratios in both directions and the shear modulus. Two distinct cases, namely lattices with thin and thick constituent members, are considered. Euler–Bernoulli beam theory is employed for the thin-wall case, and Timoshenko beam theory is employed for the thick-wall case. The closed-form expressions are validated by independent finite element simulation results. The generalized expressions can be considered as benchmark solutions for validating future numerical and experimental investigations. The conventional single-material and single-thickness homogeneous lattice appears as a special case of the heterogeneous considered here. By introducing the Material Disparity Ratio (MDR) and Geometric Disparity Ratio (GDR), variability in the equivalent elastic properties has been graphically demonstrated. As opposed to classical homogeneous lattices, heterogeneous lattices significantly expand the design space for 2D lattices. Orders-of-magnitude of variability in the equivalent elastic properties is possible by suitably selecting material and geometric disparities within the lattices. The general closed-form expressions proposed in this paper open up the opportunity to design next-generation heterogeneous lattices with highly tailored effective elastic properties. • In-plane mechanics of two-dimensional heterogeneous hexagonal lattices are investigated. • Exact closed-form expressions of the equivalent elastic properties for 2D heterogeneous hexagonal lattices are obtained. • Physics based generalized unit cell approach which exploits the stiffness parameter of the constituent element is considered. • Orders-of-magnitude of variability in the equivalent elastic properties is obtained by considering material and geometric disparities within the lattices. [ABSTRACT FROM AUTHOR]

This study examined the buckling of unstiffened cylindrical shells under external pressure. Six stainless steel cylindrical shell specimens were tested, with a length-to-radius ratio, L/R, ranging from 1 to 7. The wall thickness, diameter, axial length, and geometry of each specimen and the material properties of the corresponding sheets were measured. All cylindrical specimens were subjected to external pressure in a pressure chamber; the buckling load and final collapsed mode were recorded. This paper presents a comparison among theoretical calculations, finite element (FE) results, and experimental data for externally pressurized cylindrical shells. In the numerical calculations, true geometry, average wall thicknesses, and elastic–perfectly plastic modeling were considered. Deviation between theoretical and FE results was 0%to − 22%, and it increased with the length-to-radius ratio. Experimental results are consistent with FE results, with deviation of 2–9%, and final collapsed modes of all shells are consistent. [ABSTRACT FROM AUTHOR]

Presented in this paper is a size-dependent analysis of the surface stress and nonlocal influences on the free vibration characteristics of rectangular and circular nanoplates. Nanoplates are assumed to be made of functionally graded materials (FGMs) with two distinct surface and bulk phases. The nonlocal and surface effects are captured by the Eringen and the Gurtin-Murdoch surface elasticity theories, respectively. The Mori-Tanaka distribution scheme is also used for obtaining material properties of nanoplate. In addition to the conventional procedure of deriving the formulation, a novel matrix-vector form of the governing differential equations of motion is presented. This form has the capability of being used directly in the finite element method or isogeometric analysis. To show the effects of surface parameters and small scale influences on the vibrational behavior of rectangular and circular FGM nanoplates with various boundary conditions, several case studies are presented. [ABSTRACT FROM AUTHOR]

The continuous strength method (CSM) is a recently developed deformation-based design method for metallic structures. In this method, cross-section classification is replaced by a normalized deformation capacity, which defines the maximum strain that a cross-section can endure prior to failure. This limiting strain is used in conjunction with an elastic, linear-hardening material stress-strain model to determine cross-section capacity allowing for the influence of strain hardening. To date, the CSM has been developed for the determination of cross-section capacity under normal stresses (i.e. compression, bending and combined loading), where it has been shown to offer more accurate predictions than current codified methods. In this paper, extension of the CSM to the determination of shear resistance is described. The relationship between the normalized shear deformation capacity, referred to as the shear strain ratio, and the web slenderness is first established on the basis of experimental and numerical data. The material model and proposed resistance functions are then described. Comparisons of the developed method with the ultimate shear capacity of a series of tested stainless steel plate girders show that improved resistance predictions of test capacity over current design methods are achieved. [ABSTRACT FROM AUTHOR]

In this paper, cross folding of an elastic sheet, a common folding method in packaging a deployable antenna reflective membrane, was studied numerically with the aim of eliminating material failure in the sheet. The deformation, stress distribution, and peak stress of the sheet, as well as the effects of geometrical parameters on those properties were systematically investigated. Then two methods, i.e., central hole method and central slit method, were explored to reduce the peak stress caused by cross folding. A central slit parallel to the first folded crease was found to be most effective in reducing the peak stress. [ABSTRACT FROM AUTHOR]

This paper deals with extending the domain of applicability of a recently developed Generalised Beam Theory (GBT) formulation intended to perform elastic linear buckling analyses of thin-walled members (i) exhibiting arbitrary flat-walled cross-sections (including those combining closed cells and open branches), and (ii) acted by general loadings. These loadings, which include transverse forces acting away from the member shear centre axis, are termed “general” in the sense that they may involve the presence of pre-buckling stress distributions associated with any possible combination of all the stress tensor membrane components ( σ xx , σ ss and τ xs , for a plane stress state), including cell shear flows – therefore, all the relevant geometrically non-linear effects need to be taken into consideration. After briefly presenting the main concepts and procedures involved in the development and implementation of the above GBT formulation, this same formulation is employed to analyse the buckling behaviour of beams with different types of cross-section geometry (containing closed cells) and exhibiting different loading and support conditions. In particular, they consist of (i) a RHS cantilever acted by two tip point loads, (ii) a closed-flange I-section simply supported beam subjected to a uniformly distributed load and (iii) a two-cell RHS section cantilever acted by tip transverse forces and couples. In all cases, the loads are applied both along the shear centre axis and also along axes parallel to it and located at the beam top and bottom surfaces. The results presented and discussed, which consist of pre-buckling stress fields, buckling curves and buckling mode shapes, are obtained by means of the newly released code GBTul 2.0 and validated by means of the comparison with shell finite element values obtained with the code Ansys . [ABSTRACT FROM AUTHOR]

The Hencky bar-net model (HBM) has been shown to be a physical structural representation of the finite difference plate model (FDM). This paper extends the HBM to tackle buckling problems of rectangular plates under in-plane non-uniform loads. This class of problems requires a pre-buckling stress analysis involving plane-stress elasticity equations in order to establish the non-uniform stress distributions in the plate domain for input loads to the HBM. The converged results given by HBM compare well with existing reference solutions; thereby verifying the model. The HBM is also used to generate some new buckling solutions for rectangular plates under various point loads and partially distributed loads. [ABSTRACT FROM AUTHOR]

In this paper, a nonlinear static thermoelastic analysis of a spherical shell made of functionally graded material is performed. The material properties are assumed to be functions of both radial coordinate of the sphere and temperature. The dependence on temperature makes the governing equations nonlinear. The so-obtained nonlinear heat conduction equation is analytically solved using the perturbation technique. The approximate temperature field is then supplied to elasticity equations which are solved exactly for the case of incompressible elastic material to get displacement and stress distributions. Finally, the temperature field, material properties and radial stress versus the radial direction are shown and discussed. [ABSTRACT FROM AUTHOR]

The various assessment methods of ultimate strength for hull girder of ships or offshore structures might lead to different results and computation time. The nonlinear finite element (FE) analyses include the implicit static analysis and explicit dynamic analysis, which both can consider the large deflection and material nonlinearity during the process of progressive collapse. Comparing with the implicit static analysis, the explicit dynamic analysis can consider the transient influence of time and avoid the convergence issue in iterative procedure. The object of the present paper is to figure out a reliable and suitable FE modelling in the explicit dynamic method, which could keep the balance of the acceptable accurate results and computation resources. Several influential factors on the collapse behaviours of hull girder are discussed including boundary conditions, geometric ranges of finite element model, element types, loading methods and loading time. The results of a Suezmax oil tanker and Reckling models assessed by the explicit dynamic method are compared with that by the other analytical methods or in the experiment. [ABSTRACT FROM AUTHOR]

In this paper, the effect of growth on the stability of elastic materials is examined through a numerical approach. Growth and resorption are considered to have two main effects from the stability standpoint. Corresponding to the change in mass, the geometry of a system changes, and the critical length of the system can be modified. In addition, the growth of the material may be affected by the stress, yet it may also impose residual stresses. As a result, the material is either stabilized or destabilized by these stresses. As a general framework for the description of elastic properties, the theory of finite elasticity is employed to investigate the growth of elastic materials. Growth is taken into account through matrix multiplication of the deformation gradient. The formalism of incremental deformation is adopted to consider growth effects. Using this formalism, the stability of growing neo-Hookean incompressible cylindrical and spherical shells under external pressure is considered. Firstly, the incremental equilibrium equations and the corresponding boundary conditions for the incompressible growing shells are summarized and afterward employed in order to analyze the behavior of spherical and cylindrical shells subjected to external pressure. The generalized differential quadrature method (GDQ) is utilized to solve the eigenvalue problem that results from a linear bifurcation analysis. It is shown that this numerical method can be efficiently utilized to solve the considered problem. The results are in full agreement with the previously obtained results. In the presence of external radial pressure, an elastic shell will buckle circumferentially to a noncircular cross-section. A change in thickness due to the growth can significantly affect buckling, both in terms of the critical pressure and the buckling pattern. Finally, the effects of the thickness ratio A 1 / A 2 , mode number n , and the growth parameter γ are studied on the shell's stability. • Incremental equilibrium equations for hyperelastic growing shells are summarized. • The GDQ method is utilized to solve the eigenvalue problem. • The results are in full agreement with the previously obtained results. [ABSTRACT FROM AUTHOR]

Thin films with micro/nano scale thickness possessing ultra-high specific surface area have been widely used in opto-, thermo-, and electro-mechanical actuators for ultra-sensitive detection of physical signal change and few molecular absorptions. However, there still lacks a rigorous plate model capable of describing the large deflection and, in the meanwhile, the complex surface effects of those films, especially the coupling between surface shear stress and bulk shear deformation. In this paper, via the satisfaction of the surface balance relation in the Gurtin–Murdoch theory, we refine Reddy's third-order plate theory to accurately characterize the size-dependent deformation and uncover the influences of the surface layer on the second and third order shear deformations of micro/nano plates. It is revealed that the modified displacement field of our plate model can engender changes in local behaviors including the through-thickness distributions of bulk shear strain and shear stress, which bring about the change in global stiffness and stability of the plates, especially those with smaller length-to-thickness ratio. When the magnitude of residual surface stress increases, the stiffness and stability of the plate are enhanced, due to the amplification of bulk shear stress. Our model also indicates that miniature structures do not share entirely the same displacement field with macroscopic ones, and the method of deriving size-dependent displacement field incorporating surface effect can be extended to more complex cases. This work provides a strategy for tuning the static and dynamic behaviors of thin film devices by modifying the surface elastic constants and residual stress. • A third-order plate model satisfying the surface balance equations is formulated. • The model is an extension of Reddy's third-order plate model for micro/nano plates. • Mechanical performances of the plate alter in response to surface shear stress. • The factor at play resides in the relative magnitude of residual surface stress. • The underlying mechanism mainly lies in the redistribution of bulk shear stress. [ABSTRACT FROM AUTHOR]

This paper presents a method to perform generalized beam theory buckling analysis on thin-walled structural members with holes. Generalized beam theory (GBT) is an ideal tool for analyzing thin-walled structures because it can directly compute buckling mode participation in an eigen-buckling analysis. The GBT extension to members with holes is made by treating a thin-walled structural member as an assembly of prismatic sub-members, and compatibility constraints on the GBT modal amplitudes are introduced to connect these sub-members. GBT shear modes with nonlinear warping deformation are included in both first order and buckling analyses to account for the nonlinear normal stress distribution in the vicinity of a hole. GBT buckling mode shapes are verified with shell finite element analysis (SFEA) in three examples that highlight the potential for quantitatively documenting buckling modes initiated by the presence of holes. [ABSTRACT FROM AUTHOR]

In this paper elastic–plastic behavior of a sandwich beam with a transversely flexible core and thin faces is investigated. The elastic–plastic behavior of the core is described by a bilinear constitutive relation of the shear stress. The governing equations for linear and nonlinear regions are derived using higher order sandwich panel theory. The governing equations are solved by finite element method based on the Galerkin weighted residual method. Since the limits of the plastic regions spread through the solution, an iterative procedure is employed to obtain reliable results. Three different boundary conditions including simply supported, clamped and three point bending configurations are studied. The results are compared with the available results in literatures and a good agreement can be seen. The results reveal that as the bilinear ratio decreases the maximum of the shear stress decreases and the plastic region extends. Comparing different boundary conditions shows that by increasing the constraint of the edges, the maximum of shear stress decreases. In addition, the plastic regions spreads by decreasing bilinear ratio and the maximum growth is belonged to clamped configuration. [ABSTRACT FROM AUTHOR]

In this paper, the dynamic buckling of axisymmetric circular cylindrical shells subjected to axial impact is investigated theoretically and experimentally. The von Mises yield criterion is used for the elastic–plastic cylindrical shell made of linear strain hardening material in order to derive the constitutive relations between stress and strain increments. Nonlinear dynamic circular cylindrical shell equations are solved with using finite difference method for two types of loading which are stationary cylindrical shells impacted axially and traveling cylindrical shells impacted against a rigid wall. Experimental tests for two types of loading are performed by gas gun. Theoretical and experimental results for cylindrical shells under axial impact for different loading conditions are reported and it is found that there is a good agreement between them. [ABSTRACT FROM AUTHOR]

This paper presents a bending and free vibration analysis of functionally graded plates (FGPs) resting on elastic foundation by using an original first shear deformation theory (FSDT). This theory contains only four unknowns, which is even less than the classical FSDT. The elastic foundation follows the Pasternak (two-parameter) mathematical model. The governing equations for the bending and free vibration analysis are obtained through the principle of virtual work and Hamilton's principle, respectively. The original displacement field allows obtaining interesting governing equations. These equations are solved via Navier-type, closed form solutions. The accuracy of the current solution is verified by comparing it with 3D and other closed form solutions available in the literature. [ABSTRACT FROM AUTHOR]

The component method is widely used nowadays for the analytical prediction of the mechanical properties (rotational elastic stiffness, design resistance and ductility/deformation capacity) of steel and composite beam-to-column joints. The Part 1-8 of Eurocode 3 (EN 1993-1-8) provides expressions for the evaluation of the properties of many different joint components. However, a quick examination of EN 1993-1-8 highlights a glaring disproportion between the quantity of information related to rotational stiffness and plastic resistance, and that related to ductility and deformation capacity. For the latter, only few recommendations are provided, sometimes in line, and sometimes even not with the component approach itself. Present paper concerns one of these components, the "column web in transverse compression" (CWC), for which no information is basically available in terms of ductility. An original procedure for the prediction of the plastic deformation capacity is presented. It relies on a preliminary evaluation of the four main component properties: elastic stiffness, plastic resistance, post-plastic stiffness and ultimate resistance. Through this study, more accurate analytical formulae than those provided by EN 1993-1-8 for the evaluation of the plastic resistance are also suggested. All the developments are validated through extensive comparisons with already available experimental tests performed in various countries. • Characterization of the full-range behaviour of the column webs in transverse compression. • Improved analytical formula for the characterization of the plastic resistance. • New analytical formula for the characterization of the ultimate resistance. • New analytical formula for the characterization of the deformation capacity. • Validation of the model against a wide range of experimental results. [ABSTRACT FROM AUTHOR]

The negative Poisson's ratio (NPR) mechanical metamaterials exhibit excellent mechanical properties, whereas their low stiffness limits the development. In this paper, we investigated an NPR mechanical metamaterial: star-circle honeycomb (SCH), which possesses enhanced stiffness compared to the classical star-shaped honeycomb (SH). Based on the Castigliano's second theorem and the principle of virtual work, a theoretical model was built to calculate the effective elastic properties of the SCH, and validated by the finite element method (FEM). The comparison with the SH showed that the SCH possessed a significantly enhanced elastic modulus. Also, we find that the elastic properties can be adjusted broadly and tailored to meet the engineering needs by selecting parameters reasonably. Subsequently, the anisotropic quasi-static compression responses of the SCH were studied. The results showed that the plateau stress and energy absorption capacity in the y -direction load were both better than that in the x -direction load. The parameter study indicated that θ and ψ produced a greater impact on the quasi-static responses. A reasonable combination of parameters can give full play to the mechanical properties of the structure. This work provided a new design idea for improving the stiffness and choosing the optimal in-plane loading direction of metamaterials. • The theoretical enclosed formulas of effective elastic properties for the SCH are derived. • The coupling between thin-walled circle and corner point strongly enhances the effective Young's modulus. • The SCH exhibits two plateau stages in the y direction, while three plateau stages in the x direction. • The energy absorption of the SCH in the y direction is greatly better than that in the x direction. [ABSTRACT FROM AUTHOR]

The 2010 AISC flexural strength of I-shaped beams with slender flange was proposed based on Johnson (1985)’s experimental plate bucking coefficient ( k c ). However, our close examination revealed that most of I-beam specimens tested by Johnson to derive k c had section configuration of slender web and noncompact flange, indicating the inappropriateness of the test database itself and probable underestimation of web restraint effect in the AISC codification. In this paper, the effect of web slenderness on the elastic flange local buckling is analytically investigated using the mixed variational approach, and more accurate but still practical formula is proposed. [ABSTRACT FROM AUTHOR]

The Continuous Strength Method (CSM) is a recently developed strain based design technique that produces accurate predictions for cross-section resistances for stocky sections against individual and combined actions. This paper numerically investigates the behaviour slender stainless steel cross-sections subjected to combined loading i.e. compression plus bending. Generated numerical results and available test results were used to develop CSM formulations to tackle the conservatism shown by the current international codes in predicting resistances of slender sections. Keeping the basic design philosophy in line with the current CSM design technique, interaction equations are re-calibrated herein for slender stainless steel hollow sections. [ABSTRACT FROM AUTHOR]

The eccentrically stiffened Ceramic-FGM-Metal layer toroidal shell segments which applied for heat-resistant, lightweight structures in aerospace, mechanical, and medical industry and so forth are the new structures. Thus, the nonlinear vibration of eccentrically stiffened (ES) Ceramic-FGM-Metal (C-FGM-M) layer toroidal shell segments surrounded by an elastic medium in thermal environment is investigated in this paper. Based on the classical shell theory with the geometrical nonlinear in von Karman-Donnell sense, Stein and McElman assumption and the smeared stiffeners technique, the governing equations of motion of ES-C-FGM-M layer toroidal shell segments are derived. The dynamical characteristics of shells as natural frequencies, nonlinear frequency-amplitude relation, and nonlinear dynamic responses are considered. Furthermore, the effects of characteristics of geometrical ratios, ceramic layer, elastic foundation, pre-loaded axial compression and temperature on the dynamical behavior of shells are studied. [ABSTRACT FROM AUTHOR]

In this paper, the problem of linear elastic buckling of a simply supported rectangular plate, with a single circular cutout, subjected to uniform uniaxial edge compression is considered. The design objective is the maximization of the buckling load by determining the optimal location of the cutout. To accomplish that, a MATLAB routine coupled with finite element computation in ANSYS is employed. The study shows that the position of the center of the circular hole for the maximum buckling load remains always on the longitudinal centerline of the plate. However, the optimal center positions along this longitudinal axis for a given cutout size have great dependence on the aspect ratio of the plates. These optimal positions are reported for various values of plate aspect ratios and cutout sizes. These results are important from a design perspective and will be useful for design purposes in the future. [ABSTRACT FROM AUTHOR]

The present paper deals with an influence of the longitudinal-transverse mode on interactive buckling of the thin-walled composite girder with imperfections subjected to bending moment when the shear lag phenomenon and distortional deformations are taken into account. A plate model (2D) is adopted for the girder. The structure is assumed to be simply supported at the ends. A method of the modal solution to the coupled buckling problem within the first order approximation of Koiter's asymptotic theory, using the transition matrix method and Godunov's orthogonalization, has been used. The calculations have been carried out for square girders. [ABSTRACT FROM AUTHOR]

The effect of moment gradient on the buckling moment resistance of I-beams can be taken into account by the use of an equivalent moment-gradient factor C b . The C b factors given by the previous researchers have been derived from elastic lateral-torsional buckling (LTB) analysis of compact I-beams. However, according to the available literature it is not known whether these factors can be applied to the LTB analysis of inelastic slender-web plate girders (SWPGs). The aim of this paper is to investigate the nonlinear LTB analysis of unstiffened SWPGs subjected to central loading. To this end, a 3D finite-element model using ABAQUS is developed for the inelastic nonlinear flexural-torsional analysis of SWPGs and used to evaluate the unbraced length and load-height effects (located at center, top flange and bottom flange) on their moment-gradient factor. It was found that the C b factor given by AISC in Specification for structural steel buildings is generally unconservative for the elastic and inelastic SWPGs under the considered point load cases. Also, it was observed that the moment resistance versus unbraced length ( M – L ) relationships for the elastic SWPGs are not significantly affected by the applied load height. [ABSTRACT FROM AUTHOR]

The objective of this paper is to provide benchmark test results, explanatory shell finite element models, and preliminary Direct Strength Method prediction for cold-formed steel lipped channels undergoing torsion dominated by warping response. Although the elastic theory for the torsional response of a thin-walled cold-formed steel lipped channel member is well-developed, the extent to which warping torsion dominates the response of cold-formed steel members is not widely appreciated. Further, for cold-formed steel members in torsion little exists in terms of experimental benchmarks and even less on situations beyond the classic elastic theory, including geometric nonlinearity and post-buckling, and/or material nonlinearity from partial to full plastification of the section. Here, a typical cold-formed steel lipped channel member loaded experimentally in torsion exhibits significant strength beyond first yield. Shell finite element models of the testing correlate well with the experiments and indicate the extent of plastification as the thin-walled member undergoes torsion dominated by warping response. Idealized end boundary conditions are developed for the shell finite element model that is conservative with respect to the response, and in agreement with classical expressions in the elastic regime. The shell finite element model with idealized end boundary conditions is used to develop a parametric study on ultimate torsional capacity for members dominated by warping torsion. The results indicate that torsional slenderness may be used to predict torsional capacity and indicate that Direct Strength Method predictions for torsion for members dominated by warping torsion are possible. Preliminary design expressions for warping torsion strength prediction are provided. [ABSTRACT FROM AUTHOR]

Elastic instabilities (such as buckling) have been recognized as a promising phenomenon to design smart materials and mechanical systems. Thin-walled cylindrical shells under axial compression can attain multiple bifurcation points in their postbuckling regime due to the natural transverse deformation restraint provided by their geometry; but harnessing such behavior for smart purposes is lacking extensive study due to its notoriously high imperfection sensitivity. In this paper, the concept of seeded geometric imperfection (SGI) design is proposed to modify and control the elastic postbuckling behavior of cylindrical shells. Eigenvalue-based mode shapes were used as basic geometric forms to generate a seeded imperfection. Prototyped SGI cylindrical shells were fabricated through 3D printing and tested under loading–unloading cycles. Numerical and experimental results suggest that the SGI cylindrical shells are less sensitive to initial imperfections and load variation than uniform ones. Cylindrical shells with seeded geometry can be potentially used in the design of smart devices and mechanical systems such as energy harvesters and self-powered sensors. [ABSTRACT FROM AUTHOR]

This paper investigates the elastic buckling behavior of steel trapezoidal corrugated shear walls (STCSWs) with vertical stiffeners. On the basis of an orthotropic plate model, by utilizing the theorem of minimum potential energy and the Ritz method, the buckling loads of stiffened STCSWs can be precisely calculated using MATLAB. Then, a value of transition rigidity of stiffener is suggested and, hence formulas of elastic buckling coefficients of stiffened STCSWs are proposed. Finally, the verification of proposed formulas using a FE model shows that the formulas are validated and applicable in estimating the elastic buckling loads of stiffened STCSWs. [ABSTRACT FROM AUTHOR]

In thin-walled bars with open cross-section, built from flat walls, cases are found in which, the cantilever wall, elastically restrained in the web, is compressed, and at the same time, longitudinal variation in stresses along its length occurs. Such a wall can be analyzed as a cantilever thin plate, elastically restrained against rotation on the longitudinal supported edge. The paper presents the results of investigations into the stability of elastically restrained cantilever plates for varied stress intensity in the longitudinal direction. Graphs of plate buckling coefficients ( k ) were determined and approximation formulas were derived for technically crucial stress distributions and different degrees of the plate edge elastic restraint. The impact of longitudinal stress variation and of the degree of elastic restraint on the plate buckling modes was analyzed. [ABSTRACT FROM AUTHOR]

In this paper the impact of a hollow elastic ellipsoidal thin shell with an elastic flat half space is analyzed. Due to the nonlinearity and complexity of the impact equation, classical numerical solutions cannot be employed. A closed-form solution for this problem is accomplished, using Hertzian theory [6] and the Vella ’ s analysis [17] in conjunction with the Newtonian method and a linearization scheme. The closed-form solution facilitates a parametric study of this problem. In next step, the closed-form analytical solution is validated by other research studies and explicit finite element method. Good agreement between the closed-form solution and other numerical results is observed. Based on the closed-form solution the maximum total deformation of the shell, the maximum transmitted force and the time duration of the contact were determined. The variations of the total deflection and the transmitted force as a function of the shell thickness and the different geometry of the shell were also determined. Finally it is concluded that the closed form equations are trustworthy and appropriate to investigate the impact of elastic ellipsoidal shells. [ABSTRACT FROM AUTHOR]

This paper represents the radial vibrations of simply supported pseudoelastic shape memory alloy cylindrical shells under time-dependant internal pressure based on Donnell-type classical shell theory. The material behavior is simulated via the Boyd–Lagoudas model. The Hamilton’s principle, Differential Quadrature, and Newmark method are employed to obtain and solve the equations of motion. The phase transformation effects are studied on the time and frequency responses of the shell. Results show that the frequency response peak points have a shift to the left with respect to the natural frequencies of the linear system (pure austenitic phase) due to the phase transformation. [ABSTRACT FROM AUTHOR]

Steel plates may be classified as slender, moderate, and stocky based on their distinctive behavior characterized by geometrical buckling and material yielding. Slender plates undergo elastic buckling first and then yield in the post-buckling stage, while stocky plates yield first and then undergo inelastic buckling. Moderate plates, on the other hand, buckle and yield simultaneously. The development of low yield point (LYP) steel enables the application of steel plates with improved buckling and energy absorption capacities as lateral force-resisting and energy dissipating elements in structures. On this basis, buckling and yielding behavior of LYP steel plates with various support and loading conditions is studied in this paper from the point of view of their application in steel plate shear wall (SPSW) systems. The limiting thicknesses of standalone plates corresponding to concurrent geometrical buckling and material yielding are determined theoretically and verified through detailed numerical simulations. Effects of using LYP steel and plate aspect ratio parameter on the required limiting plate thickness as an effective parameter in seismic design of SPSW systems are investigated as well. In addition to the studies on the performance of plates with two and four restrained edges and also applicability of some extrapolation techniques for predicting the critical buckling load of moderate plates, detailed studies are performed on determination of the limiting plate thickness in code-designed SPSW systems. Based on the findings of this study, some practical recommendations are provided for efficient seismic design of SPSW systems with LYP steel infill plates. [ABSTRACT FROM AUTHOR]

This paper deals with the analytical and numerical studies of elastic buckling of a three-layered beam with metal foam core. Mechanical properties of the core are variable along the z -axis. There are two schemes of displacement of the faces and core of the beam: a broken line hypothesis and a non-linear hypothesis. The mathematical models for both types of displacements are presented. The governing differential equations of the sandwich beam are derived. Numerical analysis of sandwich beams is conducted in ANSYS environment. The finite elements analysis has been performed using a linear elastic buckling model. The analysis with constant and variable Young׳s modulus of the core of the beam is carried out. The values of the critical load obtained by the analytical and numerical (FEM) methods are compared. [ABSTRACT FROM AUTHOR]

The paper is devoted to a non-typical shape of a shell of revolution with positive Gaussian curvature. The meridian of the shell is a plane curve composed of a clothoid and a circular arc. Geometrical properties of the middle surface of the shell of revolution are presented. Pre-buckling state of the shell under uniform pressure is described analytically. The critical pressure and buckling modes for the shell are calculated with the use of the FEM (the ANSYS system). Post-buckling behaviour of the shells is shown. Results of analytical and numerical investigations are presented in tables and figures. [ABSTRACT FROM AUTHOR]

So far, the equations for buckling capacity of web panels focus on thin-walled beams with very strong flanges. In this paper, elastic buckling behavior of web panels of thin-walled beams with weak flanges is further studied, aiming at a buckling coefficient formula unifying the effect of both weak and strong flanges. A new parameter, the flange-to-web ratio of moment of inertia, is proposed to characterize the effect of flanges. Then, a semi-analytical method is applied to investigate the buckling behavior of simply supported web panels, in two cases, inclusive or exclusive of effect of the moment of inertia of flanges. It is revealed that elastic buckling load, in particular, the buckling coefficient of web panel is a function of two key parameters, web aspect ratio and flange-to-web ratio of moment of inertia. Meanwhile, a finite element analysis (FEA) model allowing for the sensitivity of boundary conditions is validated by comparing with the semi-analytical solution to the case exclusive of effect of the moments of inertia of flanges. Next, numerical results are utilized to illustrate the influence of the previous parameters, which verify the increase of buckling coefficient with flange-to-web ratio of moment of inertia or the decrease of buckling coefficient with web aspect ratio. Besides, it also verifies that for the same flange-to-web ratio of moment of inertia, the buckling behavior of square web panels is closer to the uniform shear buckling than other rectangular web panels. Finally, an accurate design formula is proposed to calculate buckling coefficient of web panel. [ABSTRACT FROM AUTHOR]

Doubly symmetric steel I-section members with thin webs and stocky flanges have a tendency to buckle in a so-called distortional buckling mode, involving distortion of the web of the I-section in the plane of its cross-section. As this mode is more complicated than the local or global buckling, analytical expressions take empirical forms and vary in between different proposals. This paper has two main objectives. The first objective is to propose a complex finite strip method for distortional buckling analysis of I-section beams with slender webs and check the suitability for such analysis by comparing its accuracy with other methods and the second objective is to propose a simple method for predicting the distortional buckling loads of I-beams. The latter objective is superior to current methods with respect to the weight of the sections. [ABSTRACT FROM AUTHOR]

Based on the vibro-acoustical model, an effective new approach to nondestructively predict the elastic critical hydrostatic pressure of a submerged elliptical cylindrical shell is presented in this paper. Based on the Goldenveizer–Novozhilov thin shell theory, the vibration equations considering hydrostatic pressures of outer fluid are written in the form of a matrix differential equation which is obtained by using the transfer matrix of the state vector of the shell. The fluid-loading term is represented as the form of Mathieu function. The data of the fundamental natural frequencies of the various elliptical cylindrical shells with different hydrostatic pressure and boundary conditions are obtained by solving the frequency equation using Lagrange interpolation method. The curve of the fundamental natural frequency squared versus hydrostatic pressure is drawn, which is approximately straight line. The elastic critical hydrostatic pressure is therefore obtained while the fundamental natural frequency is assumed to be zero according to the curve. The results obtained by the present approach show good agreement with published results. [ABSTRACT FROM AUTHOR]

The lateral-torsional buckling behavior of functionally graded (FG) non-local beams with a tapered I-section is here investigated using an innovative methodology. The material properties are supposed to vary continuously along the longitudinal direction according to a homogenization procedure, based on a power-law function, whereas the nanobeam is modeled within the framework of a Vlasov thin-walled beam theory. The flexural-torsional governing equations of the problem are derived based on the Eringen's nonlocal elasticity theory and the energy method. The system of lateral stability equations is, thus, reduced to a fourth-order differential equation in terms of the twist angle by uncoupling the equilibrium differential equations. The buckling loads are finally determined using the differential quadrature method (DQM), which is here applied as numerical tool to solve directly the differential equations of the problem in a strong form. A systematic investigation checks for the influence of some parameters such as the power-law index, tapering ratios, loading height parameter, boundary conditions and non-local parameter, on the lateral stability resistance of the tapered I-nanobeams. The numerical outcomes of this paper can be used as benchmarks for further studies on nanoscale tapered thin-walled beams. • The lateral-torsional buckling behavior of axially functionally graded non-local beams with a tapered I-section. • Eringen's nonlocal elasticity theory and the energy method. • The buckling loads are determined using the Differential Quadrature Method (DQM). • The influence of various parameters on lateral stability resistance of the tapered I-nanobeams is considered. [ABSTRACT FROM AUTHOR]