Applying parameter mapping theory, this paper establishes a new three dimension lattice-spring model with rotational degree of freedom (3D-LSMR). This 3D-LSMR contains nearest neighbor, next nearest neighbor and third nearest neighbor which highly increases the accuracy of system. Compared with the general lattice spring model, 3D-LSMR adds the rotational and tangential degrees of freedom, whose spring

We consider a static problem for statistically homogeneous matrix linear bond-based peridynamic composite materials (CMs). For the media subjected to remote homogeneous volumetric boundary loading, one proved that the effective behavior of this media is governed by conventional effective constitutive equation as in the local elasticity theory. It was made by the most exploitation of the popular tools

Strong anisotropies and/or near-incompressibility properties introduce internal constraints in material deformation. Numerical simulations comprising such a constrained behaviour show an overstiff structural response, referred to as element locking. Implementations based on mixed variational methods can heal locking but available solutions in the state-of-the-art are still non-optimal for anisotropic

This paper studies the stress intensity factors and their correlations with bimaterial parameters for the interface planar cracks by hypersingular integral equations. A new bimaterial parameter γ is defined, and the correlations of the stress intensity factors of interface planar crack with two parameters ε and γ are proved. The relative displacement fundamental function is proposed based on the crack's

This paper investigates an axisymmetric and frictionless contact problem of a coated elastic substrate pressed onto a rigid foundation with a rigid disc by remoted uniform compressive stress. Such an incomplete contact problem is formulated as three-parts mixed boundary values problem (MBVP). By means of Hankel transform technique and a new solution derived for a multilayered elastic solid subjected

Variation of pore size is relevant for both the growth of voids during fracture and the compaction of pores at compression of a porous medium. In this work we examine the previously proposed continuum model of dislocation-stimulated growth of nanovoids in Al to the case of Cu for both tension and compression of the sample with a previously cut pore. Results of continuum model are verified and parameters

A methodology for incorporating a ductile fracture criterion into an improved Marciniak–Kuczynski model, which extends the original works to include planar anisotropy using the Barlat89 yield criterion, is proposed to predict the forming limit diagram of AA7075. This is the most promising alloy to be introduced in the automotive industry, resulting in even greater weight reduction when compared with

The plastic flow in a silicon electrode during lithiation can alter the stress state in the silicon electrode and retard the fracture of the silicon electrode. In this work, we develop a rate-dependent model to investigate the plastic flow and phase transformation, which concurrently occur during the lithiation of a cylindrical silicon electrode. Using a power law for the plastic-flow potential and

A new micromechanically motivated theory is proposed to model dragline silk. A thorough review of the micro-structure of dragline silk is presented. Based on the review, a continuum framework is utilized to develop constitutive equation of dragline silk. Dragline silk is composed of a dominant soft amorphous phase (α-phase) and a reinforcing hard crystal phase, which is classified as rigid β-sheets

Axial splitting and curling behaviour of circular sandwich metal tubes with metal foam core is investigated analytically and experimentally. The sandwich tubes split axially and the strips curl outward by prefabricated cracks at the distal end of the specimens. Axial compression experiments of circular sandwich metal tubes are carried out and deformation modes are found. A theoretical model is developed

The invisible cloak has attracted great attention due to its significant influences on science and engineering. Active elastic wave metamaterials provide superior controllable characteristics for the flexural wave cloak that is obviously different from the conventional structure. In this work, a broadband flexural wave cloak is designed and fabricated by the coordinate transformation method and active

A new multi-scale framework to numerically model the bridging effect in through-thickness reinforced (TTR) composite laminates with z-pins is presented. The framework first establishes a library of bridging maps, calculated by a micromechanical semi-analytical constitutive bridging model. For the macro-scale, a tri-linear cohesive law has been developed to model initiation and propagation of the interfacial

The paper studies the problem of an extended thermoelectric spheroid placed in a thermoelectric matrix. The external electric field is assumed to be uniform. Despite the nonlinear nature of the equations, the solution of the problem can be found as a sum of Legendre functions and polynomials. The solution obtained is used to find the effective values of electrical and thermal conductivities, as well

Concertina folding of tubes used for impact mitigation bends the tube section to tight curvatures that can lead to failures on the tensioned side of the folds. This paper reports results from such axial crushing experiments on Al-6061-T6 circular tubes in which cleft-like features were also observed on the compressed sides of folds. Microscopic examination of the compressed sides of sectioned folds

Swollen nematic elastomers can deform under an applied electric field due to the electro-opto-mechanical coupling effect. This unique coupling mechanism causes the nematic elastomer to exhibit larger deformations under weak electric fields as compared to many conventional dielectric elastomers. Further, the electric-field induced deformations can be controlled by proper design of the initial liquid

Part II (Soldatos 2018b) identified some theoretical disagreement between the generally anisotropic polar linear elasticity of Mindlin and Tiersten (1962) and its counterpart developed in (Spencer and Soldatos, 2007, Soldatos, 2014) for fibrous composites with embedded fibres resistant in bending. The present communication shows that this disagreement is essentially due to inherent features of fibre-splay

A new experiment for determining the equivalent plastic strain at fracture of a ductile material subjected to loading under a state of stress of in-plane biaxial tension and out-of-plane compression is introduced. In this experiment a small diameter spherical punch is pushed into a thin specimen plate that is backed up by another plate made of a different material. Upon loading, the material element

A main problem for the development of comprehensive continuum mechanical models is the lack of experimental data. To overcome this problem, a non-associative viscoelastic-viscoplastic constitutive model which takes into account combined isotropic-kinematic hardening effects for epoxy matrix as well as a three dimensional non-associative anisotropic nonlinear elastic/plastic constitutive model for flax

Corrugated waveguides are periodic structures that exhibit important acoustic features. Features like acoustic bandgaps exhibit the ability to filter acoustic and ultrasonic frequencies. By varying the mean thickness, corrugation height, and periodicity, one can tune the propagating wave modes in the guide and thus can modify the bandgaps. This study aims to obtain a generalized Rayleigh–Lamb equation

The in-plane steady-state response of a rotating ring on elastic foundation subjected to a stationary load is investigated theoretically using a high-order model in the framework of the plane strain assumption. The adopted high-order model accounts for the through-thickness variation of stresses and displacements, as well as the boundary tractions at the inner and outer surfaces of the ring. Based

Three novel and robust homogenization schemes for polycrystals deforming in the elasto-viscoplastic regime are proposed, two of them of the self-consistent type and the other combining self-consistent and Mori-Tanaka methods. In addition, a non-incremental interaction equation for an elasto-viscoplastic inhomogeneity problem is also derived. Second moments of stress and strain field distributions within

The compressive behaviour of cross-ply laminates with delaminations and matrix cracked layers is investigated by means of an analytical modelling approach. Insight into the post-buckling and damage growth behaviour is obtained owing to comprehensive parametric studies varying delamination length and depth as well as matrix crack density for cross-ply laminates with different layups. The efficient modelling

Cosserat continuum model has attracted increasing interest for describing the mechanical behavior of microstructured solids. Existing formulation of Cosserat continuum model often overlooks chiral effects that arise from coupling between stretching deformations and the micro-rotation. Here, we introduce an extended Cosserat model that accounts for such a coupling. We discover the links of the extended

This paper proposes a micromechanical approach aimed at identifying the response of unidirectional fuzzy fiber composites undergoing inelastic fields. Fuzzy fibers are reinforcement fibers coated with radially aligned straight or wavy carbon nanotubes grown through chemical deposition process (PVD or CVD). Due to this nature, the composite with fuzzy fibers is described by three scales: i) the microscale

This study presents a general approach to the topology design of tensegrities with rigid bodies. To the best of the authors’ knowledge, all existing topology design methods of tensegrities focus on tensegrities that only consist of members carrying axial forces, which are referred to herein as classic tensegrities. However, another category of tensegrities, referred to as general tensegrities, contains

The plastic bending of a sheet metal having tension/compression asymmetry was investigated in this work with AZ31B Mg sheets, particularly focused on its deformation behavior. With the assumptions of pure bending and rigid plasticity, analytic expressions were obtained to describe sheet bending under the plane strain condition, taking into account the movement of the neutral surface and the associated

The manuscript presents a novel reduced order homogenization model for oxidation-assisted rupture in SiC/SiC composites at intermediate temperatures. Starting with a one-dimensional model based on the slow crack growth model originally proposed by Iyengar and Curtin, which is subsequently generalized to three dimensions focusing on the woven composite architecture. The proposed oxidation-assisted rupture

We present the analytical formulation and the finite element solution of a fractional-order nonlocal continuum model of a Euler-Bernoulli beam. Employing consistent definitions for the fractional-order kinematic relations, the governing equations and the associated boundary conditions are derived based on variational principles. Remarkably, the fractional-order nonlocal model gives rise to a self-adjoint

This paper presents a new force method to predict the structural response of statically and kinematically indeterminate systems that can be stabilized through prestress, i.e. prestress-stable structures. This new force method, here named Extended Integrated Force Method (IFME), extends the existing Integrated Force Method (IFM) which is only applicable to the analysis of kinematically determinate systems

Modern superconducting intermetallic materials (e.g. NbTi, Nb3Sn) are used to build conductors composed of a matrix and the superconductor strands. One of the most popular materials for matrix is copper, because of its excellent physical and mechanical properties at extremely low temperatures. Ductile OFE copper stabilizes, on one hand, the mechanical response of brittle superconductor strands and

The spatiotemporal evolution of macro-domain patterns in a NiTi thin strip during non-isothermal stress-induced phase transformation (PT) are investigated through 2D FEM simulations using nonconvex nonlocal continuum model and 1D theoretical analysis. The FEM simulations shows that, with the increase of applied stretching rate (nominal strain rate), the way of PT in a thin strip (30mm×2.5mm×0.5 mm)

A model for the prediction of localised necking in plates subjected to dynamic biaxial loading is presented. The proposed model extends the classic two-zone localisation analysis introduced by Marciniak and Kuczyński (1967) to include the contribution of inertia. Several examples of computations are presented to illustrate the influence of inertia, material rate-dependence and yield surface shape on

A new approach for the systematic development of constitutive models for composites is proposed. The approach relies on the generation of a representative volume element of the composite microstructure, which in this case is a flax fibre/epoxy matrix unidirectional composite. The microstructure is subjected to different deformation states based on which the deformation profile as well as the yield

The in-service deformation damage cannot be avoided, even for micro-scale metallic materials. To characterize the coupling effect of size and damage in micro-metallic materials, a modified incremental constitutive model is proposed on the basis of the conventional theory of mechanism-based strain gradient plasticity (CMSG), in which the assumptions of both small strain and isotropic damage are adopted

Composite laminates are usually made of anisotropic viscoelastic materials with layer-dependent properties. Although such structures are advantageous over the traditional single-material structure, their interfacial damage/failure is a great concern. In this paper, we present the general formulation and the corresponding solution to enhance our understanding on the guided waves in such laminates with

An improved distortional plasticity framework that describes the anisotropic hardening occurring during strain path changes, such as the Bauschinger and cross-loading effects, is developed. This approach is a modified version of the homogeneous anisotropic hardening (HAH) framework proposed almost a decade ago. In the present formulation, the yield condition includes an alternative description of the

A thermomechanical consistent model for cyclotetramethylene tetranitramine (HMX) is developed, which considers material anisotropy, nonlinear thermoelasticity, dislocation-based plasticity, shear cracking induced damage and physical-based phase transformation. The proposed model is employed to investigate the mechanical-thermal-phase transformation response of oriented HMX single crystals under isentropic

By introducing relaxation summands in the formula of Hooke’s law, in order to consider the finite propagation velocity of stress and deformations, an equation for damped oscillations of an elastic rod was obtained, including, as opposed to the well-known equation, the third derivative of motion in time as well as the mixed derivative of the spatial variable and time. By using Fourier’s method, its

The present paper analyzes the optimal nose shape of an axisymmetric rigid projectile which penetrates into a thick target. The optimal projectile nose shape is defined as the shape on which the minimum resistive force is developed in its interaction with the target. This resistive force sums up the contributions of the contact interaction pressures acting on the projectile nose envelope. The interaction

The scope of this work is to investigate how the interfacial pressure and the scale of the asperities as well as the temperature, influence the thermal contact conductance TCC in rough surfaces under low pressure. For that, a two- dimensional numerical model is developed, in which the macroscopic TCC coefficient is obtained from the solution of the heat conduction problem at the scale of asperities

Rolling contact fatigue cracks often initiate in the highly deformed surface layer of railway rails. However, the behavior of the material in this region is not well known. In an earlier study by the author the behavior of a pearlitic rail steel subjected to large shear deformations was analyzed experimentally. The purpose of the present study is to evaluate the ability of four different material models

Concrete is a predominant construction material due to a number of advantages. Disadvantages are given by its limited tensile strength and brittle tensile failure behavior. Fiber reinforced cement composites (FRCC) can improve these weaknesses to a large degree. But a proper composition design especially with respect to fiber and bond properties still follows a trial and error approach. Suitable simulation

This paper proposes an analytical model that uses historical damage dimension data to deduce physical impactor characteristics (size and energy) that has caused a certain resulting damage. Maintenance tasks occur in operations due to impact, however the source of the damage caused in the event remains in most cases unknown. Consequently, by inferring what has caused a certain type of damage from the

A theoretical frictional contact model of thermoelectric materials with nonlinear thermoelectric coupling loaded by a sliding punch is considered in which the punch is also assumed to be an electrical and thermal conductor. For the electric fields and the temperature fields, some analytical results are obtained by Fourier transform technique, such as the full field closed-form formulas of the electrochemical

Various caloric aspects of polycrystalline ferroelecrics are investigated, based on an efficient modelling approach. In this context, both linear reversible effects, leading to heating or cooling of the material, and nonlinear dissipation heating, being associated with ferroelectric domain switching, are considered. The semi–analytical approach focusses on the constitutive behavior of a polycrystalline

A unified semi-analytical solution based on graphical conformal mapping and complex variable methods is proposed to calculate the in-plane stress around an arbitrarily-shaped hole in isotropic or anisotropic materials. The method requires only the outline coordinates of the hole, the elastic moduli of the material, and the magnitude and direction of the far-field stresses. Comparison with many published

Microstructures with two distinct size-scales of voids are commonplace in additively-manufactured metals. The smaller-scale voids nucleate from inclusions within the metal, while the larger-scale voids originate from unsintered powder particles. In this work, we study the interaction between these two size-scales of voids ahead of a crack, and the influence on the ductile fracture process. We adopt

The parameter retrieval method based on scattering data is used to derive dynamic constitutive parameters of solids with periodic structure. There are inherent ambiguities in the real part of the retrieved wavenumber and the sign of impedance, though the latter has a one-to-one correspondence with the direction of energy flux. Moreover, for lossless structures there can be multiple solution branches

Sheet metals exhibits plastic anisotropy due to the rolling process. This article focuses on the particular case of an 2024T351 Aluminium alloy thick sheet which showed in addition to the anisotropy of mechanical properties an important evolution of the these properties along the thickness. A large series of tension tests performed is carried out using samples machined varying the position along the

This paper develops a high performance scalable computational model for simulating coupled transient electric and finite deformation dynamic fields with widely discrepant frequencies, governing the behavior of piezoelectric materials in the finite element framework. The nonlinear piezoelectric constitutive laws are formulated in the context of continuum damage models (CDM) at finite deformation. A

A thermodynamics-based coupled damage-plasticity model for high strength cold-reduced steel is developed on the basis of a generic form, allowing the use of any yield criterion and damage evolution rule. The model possesses essential features of ductile failure, including large plastic deformation prior to fracture and the effects of both triaxiality and Lode angle on the failure. In conjunction with

A semi-analytical solution for an elastic/plastic sphere subject to thermo-mechanical loading is given. Material properties are temperature dependent. The solution is valid for any isotropic pressure-independent yield criterion. Even though the general solution in both elastic and plastic regions is rather simple, the solution of the boundary value is cumbersome. The solution is facilitated by using

Experimental studies are conducted to investigate the implosion characteristics of thin cylindrical aluminium-alloy tubes. The effects of various parameters that generate different responses on the implosion behaviours are investigated. Aluminium-alloy tubes are fabricated from a 6061-T6 material and designed in the range of 2.5–6.7 length-to-diameter ratios; wall thickness-to-diameter ratios are varied

Thin elastomer layers bonded on a rigid substrate can be found in diverse engineering applications, in which the elastomers are often in stressed state. Previous studies have shown abundant evidence that the prestresses in an elastomer layer can greatly influence its mechanical behaviors. In this article, we have analytically derived the surface Green's function of a stressed elastomer layer with finite

Periodic structures are a type of metamaterial in which physical properties depend not only on the constituents of the unit cell but also on how the unit cells are arranged and interact with each other. Such structures have interesting wave propagation properties, making them suitable materials for acoustic filters and wave beaming devices. To analyze wave propagation in these structures, the Bloch

Approaches to systematic analysis of essentially nonlinear structures with multistable responses, controlled buckling and snapping behavior have received much attention recently in the context of mechanical metamaterials design. A snapping bistable element is generally a highly efficient damper, performing well even at very low forcing frequencies. In this paper, we transfer basic tools of the metamaterials