Negative stiffness structures (NSS), as a branch of multi-stable mechanical metamaterials, exhibit multiple stable configurations. Their characteristics, such as bistability, snap-through and negative stiffness, make them particularly suitable for shock absorber applications. The majority of NSS is designed in a cuboidal shape and only recently few studies focused on cylindrical NSS. Lately, Fraunhofer

In this article, different standard and nonstandard continualization techniques are applied to a one-dimensional solid consisting in a chain of masses interacting with nearest and next-nearest neighbors through linear springs. The study focuses on the reliability of the different continua in capturing the dispersive behavior of the discrete, on the order of the continuous governing equation because

In this study, an accurate 1D finite element model with low degrees of freedom (DOFs) is presented for the static extensional-shearing-bending analysis of curved thin-walled beams. In order to incorporate the nonclassical effects like transverse shear flexibility in the formulation, the concept of equivalent layered composite cross section (ELCS) is employed. Based on this new concept, the cross section

(2020). Correction. Mechanics of Advanced Materials and Structures: Vol. 27, No. 16, pp. 1459-1459.

The strong, stiff and weight efficient composite cylindrical shells with metal liner can withstand axial load, transverse load and higher internal pressure. In this paper, a composite corrugated sandwich cylinder with thin-wall metal liner was fabricated by integrated-solidification. Then, the damage and failure modes of the sandwich cylindrical shells were tested by quasi-static uniaxial compression

An interesting phenomenon observed in auxetics (materials with negative Poisson’s ratio) relates to appearing anomalous velocity intersections of the interfacial Stoneley waves at varying acoustic properties of the contacting media satisfying Wiechert condition. Comparative analysis with the non-auxetics (materials with positive Poisson’s ratio) revealed the absence of such intersections. The analysis

The objective of this paper is to gain insight into the implementation of 3D finite elements in curvilinear coordinates using the fundamental equations of 3D elasticity and the Principle of Virtual Displacements. After reviewing the mathematical model of the geometry, we present the formulation of hexahedral finite elements that represent a generalization of classical shell finite elements, in which

In the recent years, isogeometric analysis (IGA) has found wide application in modeling different types of discontinuities produced by cracks, contact surfaces and bi-material interfaces. This technique eliminates the geometry discretization errors associated with the representation of complex geometries. The present paper employs the extended isogeometric analysis (XIGA) and the coupled finite element-isogeometric

In this article, free vibration finite element analysis of variable stiffness composite laminate (VSCL) beams is carried out. The variable stiffness of laminated beams is acquired by using laminates with curvilinear fibers instead of straight fibers. The analysis is based on the higher-order theories that have been presented by Carrera Unified Formulation (CUF). Equivalent Single Layer (ESL) model

The present paper is dealing with a new mathematical model of a thermoelastic semiconducting solid sphere based on the Green-Naghdi theories to study the photothermal interaction. We applied two considerations: the mechanical damage variable, and rotation with constant speed. The bounding surface of the sphere has been thermally loaded by thermal shock. Laplace transform has been applied, and its inversions

New higher-order models of orthotropic micropolar plates and shells have been developed using Carrera Unified Formulation (CUF). Here, a complete linear expansion case (CLEC) has been considered in detail. The stress and strain tensors, as well as the vectors of displacements and rotation, have been presented as linear expansion in terms of the shell thickness coordinates. Then, all the equations of

In this study, the finite element method was used to predict the brittle fracture path using the phase-field approach. The staggered algorithm was adopted owing to its proved robustness. In order to reduce the computational time, an optimization method of matrix assembly was proposed. Then, a comparative study was performed between the isotropic and the hybrid formulations. Numerical tests were computed

Abstract Large deflections relevant for suspended circular graphene sheets with simply supported boundaries are computed by a theory for 2D membranes subjected to several types of vertical axisymmetric forces, based on the principle of virtual power (PVP). Corresponding stress–strain relations are provided in the form of a nonlinear hyperelastic material model for graphene. When approximating the deflections

A novel mathematical formulation is presented for the applications of the stress-driven nonlocal theory of elasticity to engineering nano-scale problems requiring longitudinal discretization. Specifically, a differential formulation accompanied with novel constitutive continuity conditions is provided for determining exact closed-form solutions of nonlocal Euler-Bernoulli beams with loading discontinuities

An appropriate finite element model is developed to simulate the high velocity impact of projectiles on polyurethane foam filled aluminum honeycomb. First, the numerical model of the high velocity impact of the projectiles on the empty aluminum honeycomb is developed using a strain rate dependent material model. A VUMAT subroutine including two different fracture criteria proposed by researchers is

(2020). Correction. Mechanics of Advanced Materials and Structures. Ahead of Print.

This study presents a multiphysics Internal State Variable (ISV) theory that couples the thermo-elasto-viscoplastic-damage model of Bammann with electroplasticity and other electricity-related electromagnetic phenomena. The model framework features internally consistent kinematics, thermodynamics, and kinetics. The abstraction of the developed ISV model can capture the full spectrum of multiphysics

In a concrete-filled steel tube (CFST), dry shrinkage and creep produce a circumferential gap between the inner concrete core column and outer steel tube that is increased by harsh weather in cold regions. Thermomechanical coupling finite element analysis was performed to determine the temperature fields, stresses, and strains of CFST arch bridge ribs with circumferential gaps. A traction–separation

Based on the octagonal truss, a new lightweight lattice impeller (L-impeller) is designed. The 3D printing process of the design impeller is simulated by Finite Element Method (FEM). The machinability and simulation feasibility of the design impeller are verified by SLM280 Metal 3D printer. The printing process of L-impeller and solid impeller (S-impeller) under different power is analyzed and compared

Wavy pattern circuits are widely used in flexible displays, wearable devices, and biosensor research. In this study, we propose a tilted 2D stretchable wavy circuit design to enhance circuit integrity and reduce electric resistance of stretchable devices. The experimental and finite element analysis revealed that the tilting wavy circuit section increased the maximum stretch ratio of the circuit and

The current work investigates the influences of different surface modifications on the flexural characteristics of carbon fiber reinforced aluminum (AA2024-T3) laminates fabricated at 3/2 sequence. Among all types of surface modifications, mechanical abrasion by 220-grit paper shows highest flexural strength. The flexural load of Al/0°/Al/0°/Al configuration is about 19% higher in comparison with mechanical

This study is dedicated to implement hygro-thermo-mechanical nonlinear analysis of curved thin and moderately thick shallow panels, in which Functionally Graded Materials (FGMs) are employed through the thickness. Based on the rule of mixture, three different patterns of FGMs, including power, exponential and sigmoid patterns are used in formulation. The distribution of porosity within the material

The Hellinger-Reissner principle is applied to derive a hybrid-mixed quadrilateral finite element with embedded-discontinuity in displacements, which can model a discrete crack (interface) within the element, and its sliding (and opening). The chosen material models are elasto-plasticity with hardening for the bulk, and traction-separation plasticity with softening for the interface. The latter model

Based on the modified reinforced rubber and the hypothetical porosity of the material, the compression properties of elastic rubber with different densities were studied. The experimental results show that the elastic deformation ability within a certain range of the density of the modified rubber, and the rigidity increases with the density enhancement. At the same time, the relationship between the

A review of the experimental and theoretical research on electroplastic deformation of metals is presented herein. We focus on the fundamental physics of electro-mechanical couplings and on the numerous mechanical, electroplasticity, thermal, electric, and magnetic phenomena that occur simultaneously when an electric current is passed through a mechanically loaded conducting metal. Suggestions for

Uncertainty propagation (UP) of the frequency response is essential for the robust design of viscoelastic damping structures. One challenge in solving this problem is enormous computation cost from the UP analysis. This paper aims to develop a novel computational effective method based on the combination of the adaptive sparse grid collocation (ASGC) method and the high dimensional model representation

This article presents a method to achieve the vibration response of wheel–rail beam system on the container crane and to reduce the vibration and improve the trolley speed. To investigate the coupled vibration of a trolley–beam dynamic system, the governing equation is excited to obtain the interaction during the trolley travel on the beam at high speed. We studied the wheel–rail beam system in the

This article proposes a three-dimensional (3D) stochastic progressive damage simulation model for the fiber-reinforced polymer matrix composite laminates. Constituents’ strength and fracture energy of each lamina were accounted as spatially varying random fields by 3D Karhunen–Loeve expansion method. Damage mechanisms modeled by continuum damage mechanics include internal damages of matrix and fiber

In this article, on the basis of Bernoulli-Euler beam theory, an axially functional gradient (AFG) flexoelectric nanobeam model incorporating strain gradient elasticity effect is established. By utilizing the Hamilton principle, the governing equations and associated boundary conditions are obtained. The generalized differential quadrature method (GDQM) is utilized to solve the governing equations

In this paper, by use of test combined with numerical simulation, the out-of-plane loading-bearing failure process of CFRP and C/C joints were studied, while Hashin failure criterion was selected to predict the damage and the failure morphologies were observed. Results show that the failure process of CFRP joint is characterized by a three-peak mechanical response and bending failure accompanied the

The aims and objectives of the current study are to investigate the vibration analysis of the graphene sheet with attached spring, mass, and damper system for the first time. For this purpose, the governing equation is derived employing Hamilton’s principle regarding the nonlocal Eringen theory. The graphene sheet is supposed to be rested on a Winkler elastic foundation. Galerkin’s method is being

In this work graphene coatings have been deposited on aluminum alloy samples to investigate whether they can improve wear strength and promote friction reduction, which means components reliability and efficiency. Tribological performance has been tested by pin-on-disk wear tests. Three procedures to coat the samples have been explored. One is based on transferred graphene method and the other two

The never-ending struggle to design new materials for supporting innovative engineering requirements gives composites a worthy focus. This endeavor is challenged by the anisotropic nature of composite material that needs virtual simulations based on non-linear multi-scale modeling. Unfortunately, to accurately characterize the nonlinear behavior of composite materials and to determine the optimized

The optimal stacking sequence design for the maximum frequencies of the lowest three modes of symmetric variable stiffness composite laminated beams in air and in water is investigated for the first time using a layer-wise optimization method. Two fiber orientation angles in each layer are considered as design variables. The shifted path technique is used to construct the fiber paths. The p-version

The application of Shape Memory Alloys with superelastic behavior (SMA–SE) to reduce vibrations in rotor systems has been studied in recent years. However, the current SMA damper device design does not prioritize improving the distribution of applied force due to vibration levels. In this sense, this paper aims to study (theoretical and experimentally) two different types of passive damper devices

In this work, a combination of the spectral stochastic finite element method (SSFEM) and the time-domain spectral element method (TSEM), referred to as the stochastic time domain spectral element method (STSEM), is presented to compute the stochasticity of strain and stress of a higher-order sandwich composite beam with spatial variability in the material properties. The method proposed in this work

The problems of periodic mode I 3 D cracks for an elastic layer are reduced to an integro-differential equation (IDE). The principal part of the IDE is the same as in the classical Griffith problem for one crack in an elastic full space. The periodic system of elliptic cracks, featuring equal spaces between neighboring cracks, lies in the middle plane of the layer. Each crack is parallel to the layer’s

Many environmental problems can be ascribed to agricultural waste. Millions of tonnes of agricultural waste, such as banana and date palm trees, are produced worldwide. Such waste is converted and recycled as natural fiber. On the other hand, a major problem of high-strength concrete (HSC) is the sudden failure at the ultimate capacity of concrete. To solve these problems, this work investigated the

Guided wave propagation and its dispersion phenomenon in infinite solid elastic rods are encountered in several applications including, mechanical and civil engineering fields. A robust root finding method based on the Padé approximation is presented for studying the dispersion characteristics of guided wave motion in a solid cylindrical rod with a circular cross-section. The theoretical analysis is

In this article, an accurate mixed zigzag theory (HZZTM) is proposed for free vibration analysis of laminated composite and sandwich plates. In-plane displacements in the proposed zigzag theory nonlinearly distribute through the thickness and exhibit an abrupt discontinuity of slope at interfaces, which coincide with three-dimensional analysis. In order to obtain the accurate transverse shear stresses

An effective three-dimensional model of the knee joint biological structure was established based on the knee joint biological structure, CT images and MRI data of 65 adult bones provided by medical institutions. The static and dynamic mechanical properties of the joint model were analyzed by finite element method under different conditions. The results show that with the increase of body weight, the

In this study, a dynamic model of a sandwich beam with viscoelastic coating based on a fractional constitutive equation was developed. The fractional model is a generalized model of sandwich beams and can be modified into integer models. The wave propagation method was extended for vibration analysis of fractional sandwich beams. Further, the influence of fractional order and size parameters on the

In this article, the shock resistance of a composite armor subjected to the underwater explosion (UNDEX) was numerically analyzed. The effects of the scaled distance and the thickness of the layers have been investigated by measuring the effective stress and the maximum elastic deflection of the target layer. After validating the results by comparing with the experimental outcomes, the optimal values

Additive manufacturing brought to the emergence of a new class of fiber-reinforced materials; namely, the Variable Angle Tow (VAT) composites. Automated fiber placement machines allow the fibers to be relaxed along curvilinear paths within the lamina. In theory, the designer can conceive VAT structures with unexplored capabilities and tailor materials with optimized stiffness-to-weight ratios. In practise

Eastern Sicily’s historic buildings are characterized by an almost uniform use of local and naturally available calcareous and lavic stone as aggregate. Also, ancient mortars comprise of lime or cement-lime binder. Very limited studies concerning the mechanical properties of the ancient mortars have been accomplished. In this paper, mortar samples collected from the surviving heritage masonry structures

In order to meet the needs of vibration reduction in complex vibration environments, one-dimensional phononic crystals constituted with periodic tunnels on elastic foundations are proposed. The governing equations of the flexural wave in a periodic structure are established based on Euler beam theory and its band structure is calculated by the plane wave expansion method. The theoretical and numerical

In this paper, flexural wave in a steel-concrete composite beam with periodically surface-bonded cement-based piezoelectric patches (CPP) is studied. The composite beam is designed using the idea of the phononic crystals. The external capacitor shunt circuit is connected to the CPP for regulating the band gap of the composite beam. The flexural wave equations are established by Euler beam theory. Using

A first-of-its-kind look-up matrix for determining ideal foam density against a spectrum of blast loads is developed to design an efficient foam-based blast absorber. A numerical study is carried out based on the principle of maximum blast energy absorption at minimum transmitted force. The model used in this study is developed using quasi-static compression test data. Comprehensive shock tube experiments

A multimaterial strategy is adopted in combination with the structure innovation to achieve enhanced structural stiffness, and meanwhile, to retain the auxetic behavior for auxetic metamaterials. A bimaterial reentrant structure with additional soft arch-like beams and hinges is proposed, and then investigated using both experimental and simulation approaches. The results indicate that the buckling

To improve the pistachio harvesting rate, the force in the process of the harvest is analyzed, and it is found that the major factors affecting fruit vibration shedding are excitation force-frequency, amplitude and clamping height. The effective range of the vibration frequency is obtained through modal analysis. The rigid-flexible coupling model of the vibration device and tree reveals the response

“Rock bed” mechanism and its formation were discussed in this article. Inspired by the bionic wear-resistant structure, the shape and parameters of an impact crusher chamber are optimized. Taking both crusher strength and crushing effect into consideration and using discrete element method, the parameters of the impact crusher chamber were properly optimized. By adjusting the major parameters and structures

A high-performance semi-analytical formulation based on the three-dimensional piezoelectricity theory for bending response and free vibration analysis of circular cylindrical piezoelectric panel subjected to the mechanical and electrical loads is presented. To ensure the accuracy and reliability for the proposed method, a normalized formulation is applied for the constitutive equation of the circular

This paper proposes an enhanced Cohesive Zone Model (CZM) for the prediction of delamination in curved beams of epoxy carbon laminates. This model improves the conventional CZM, taking into account the fiber-bridging phenomenon and the variation of the element size among the thickness in the curved zone. The advantages of the enhanced model are underlined when results obtained from the numerical simulations

The p-version of the finite element method based on the first-order shear deformation theory (FSDT) is applied, to the free vibration of symmetric variable stiffness composite laminated (VSCL) elliptical plates, with curvilinear fibers. A curved hierarchical rectangular finite element is developed and used to model the elliptical plate. The geometry is described accurately by the blending function

We propose a novel mixed displacement-pressure formulation based on an energy functional that takes into account the relation between the pressure and the volumetric energy function. We demonstrate that the proposed two-field mixed displacement-pressure formulation is not only applicable for nearly and truly incompressible cases but also is consistent in the compressible regime. Furthermore, we prove

This paper presents the static and mechanical buckling analyses of thick functionally graded (FG) plates. For this purpose, Carrera’s unified formulation (CUF) and the principle of virtual displacement are employed in the numerical finite strip method (FSM). CUF transforms the governing three-dimensional (3D) elasticity equations to quasi-3D ones by employing a set of thickness functions. Since this

The influence of strength–differential (SD) effect has been investigated on Johnson–Cook (JC) material model parameters for armor grade RHA steel. Two set of JC model parameters has been developed with the help of compressive and tensile flow curve. Further, a finite element analysis (FEA) of static (at 10−3 s−1) and dynamic indentation (at 104 s−1) has been performed to validate the effect of tensile

A supervised machine learning framework is proposed for local assessments of delamination and transducer debonding in smart composite laminates while using their low-frequency structural vibrations. Load independent discriminative features were identified through a system identification algorithm and several supervised machine learning algorithms were employed to distinguish between the healthy and

Tuning load-deflection curves is of significant importance in advanced structural design. In this paper, by introducing densely distributed edge cracks artificially, the N-shaped load-deflection curve with snap-through instability is realized in the axially pre-compressed, simply supported beam made of tough material under transverse uniform pressure. A simple mechanics model is established based on

A new balanced laminate of piezoelectric fiber composite (PFC) is presented for the improved shear mode piezoelectric actuation of beams. A micromechanics formulation is first presented for determination of its effective electromechanical properties, and then its shear actuation capability is investigated by means of utilizing it for actuation of bending deformation of a smart sandwich beam. The results