A coupling convected particle domain interpolation based implicit material point method (ICCPDI) is developed in this paper for the long-time consolidation and dynamic problems of fully saturated porous media involving massive deformation. In the method, the implicit formulas based on the u-p form governing equations are derived to overcome the time step size limitation within the conventional explicit

This paper explores the high-accuracy analysis of bending and frequency response of the sandwich cylindrical shell with functionally graded (FG) carbon nanotubes reinforced composite (FG-CNTRC) face-sheets and polymeric core under the effect of initial axial stress and various mechanical loading based upon the three-dimensional theory of elasticity for various sets of boundary conditions. The sandwich

Multi-crack propagation is investigated mainly by experimental measurement and little by theoretical prediction. The classical fracture criteria can better predict tensile fracture under arbitrary loading conditions (pure tensile, pure shear and mixed-mode), but have difficulty in predicting shear fracture. In this paper, Mode I and Mode II SIFs of branch-cracks initiated by the original cracks were

This study numerically investigated the behavior of a Newtonian droplet impacting a heated porous surface. In this regard, a two-phase finite volume code was used for laminar flow. The time adaptive method was applied to enhance the accuracy of results and better convergence of the solving process. Also, the dynamic grid adaptation technique was adopted to predict the liquid-air interface precisely

Origami-inspired structures have found many innovative applications in engineering fields. The expressive volume changes intrinsically related to their geometry is very useful for different purposes. Nevertheless, the mathematical description of origami structures is complex, which makes the design a challenging topic. This work deals with the use of reduce-order models for the origami description

In this paper, the thermo-acoustic behavior of a rectangular panel fully immersed in a compressible fluid at rest is investigated. A boundary element method (BEM) has been employed taking into account the Kirchhoff–Helmholtz (K-H) integral equation for the acoustic pressure and with the fluid-plate interface boundary condition the acoustic pressure jump over the panel is calculated. The thermal effects

This paper proposes a theoretical model for the description of tension-compression cyclic plasticity of gradient nanostructured (GNS) metals. The gradient grain size effect is considered by introducing the Hall–Petch relation for local yield stress and strain hardening. With the experimentally measured grain size distribution profile, the average axial stress can be calculated for cylindrical GNS metal

We propose a machine learning embedded method of parameters determination in the constitutional models of hydrogels. It is found that the developed logistic regression-like algorithm for hydrogel swelling allows us to determine the fitting parameters based on known swelling ratio and chemical potential. We also put forward the neural networks-like algorithm, which, by its own property, can converge

The mechanical properties and deformation of Origami structures are studied in this paper. Usually, it is a coupling problem of crease rotation and shell deformation. Here, the creases are simplified as torsional springs, whose rotational stiffness k is obtained by the experiment of compressing a creased shell. While the shells that may have large deformation are simplified as rigid plates connected

This study concerns the effect of applied velocity on the energy state and stress state related to the puncture-cutting of soft material. A finite element modeling (FEM) of combined puncture and cutting of neoprene rubber by a pointed blade was established at 17 velocities (from 10mm/min to 1500mm/min). The proposed FEM takes into consideration, the nonlinear material behavior of the elastomeric substrate

This paper proposes an interval finite element method based on function decomposition for structural static response problems with large-scale unknown-but-bounded parameters. When there is a large number of uncertain parameters, it will lead to the curse of dimensionality. The existing Taylor expansion-based methods, which is often employed to deal with large-scale uncertainty problems, need the sensitivity

The space flexible arm has the characteristics of large flexibility and size, and external excitation will cause harmful vibration. In this paper, the dynamic response of flexible arms is analyzed, and the vibration control is studied when nonlinear factors are considered. First, the vibration equation is established according to the Hamilton’s principle, and the generalized force is derived by using

The CoCrFeMnNi high-entropy alloy (HEA) is a potential structural material, whose cyclic plasticity is essential for its safety assessment in service. Here, the effects of twin boundaries (TBs) and temperature on the cyclic plasticity of CoCrFeMnNi HEA were studied by the molecular dynamics (MD) simulation. The simulation results showed that a significant amount of lattice disorders were generated

This paper investigates the nonlinear bending analysis of a hyperelastic plate via neo-Hookean strain energy function. The first-order shear deformation plate theory (FSDPT) is used for the formulation of the field variables. Also, the nonlinear Lagrangian strains are considered via the right Cauchy–Green tensor. The governing equations and nonlinear boundary conditions are derived using Euler–Lagrange

This paper conducts theoretical study on the mechanical, thermal and electrical properties of graphene reinforced composites by effective medium theory (EMT). Considering the imperfect bonding between the reinforcing fillers and the matrix, an interphase surrounding the graphene fillers is introduced during the EMT modeling. The coated graphene fillers are homogenized as effective reinforcements dispersed

The morphology of a bleb and its changes are critical to the amoeboid migration of a cell. By releasing bonds between the membrane and the cortex of a cell, the formation of a bleb can be observed experimentally, but the mechanism that affects the size and shape of a bleb during amoeboid migration requires further study. In this study, by adapting the governing equations and discrete equations of the

In this paper, an improved conforming AFEM (C-AFEM) for efficient modeling of arbitrary crack propagation and branching is proposed and validated. An explicit formulation for branching cracks has been derived within the C-AFEM framework. The conjugate gradient method is integrated into the C-AFEM formulation to solve the local problem that consists of all elements traversed by single or multiple cracks

As one of the most popular 3D printed metamaterials, the auxetic structure with its tunable Poisson’s ratio has attracted huge amount of attention recently. In this study, we designed an auxetic shape-memory metamaterial, which showed designable buckling responses by using the thermomechanically coupled in-plane instability. The influence of viscoelasticity on in-plane moduli and Poisson’s ratios of

In this paper, elastic wave scattering in hollow pipes with non-axisymmetric and inclined angle defects is studied using finite element (FE) simulations. A comb array transducer is employed in the FE code to excite the pipe in its first longitudinal mode using a 10-cycle sine modulated excitation signal at 120kHz central frequency. Defects with variations in geometrical shapes such as depths, axial

A mid-node mass lumping scheme is proposed to formulate the lumped mass matrices of serendipity elements for accurate structural vibration analysis. Since the row-sum technique leads to unacceptable negative lumped mass components for serendipity elements, the diagonal scaling HRZ method is frequently employed to construct lumped mass matrices of serendipity elements. In this work, through introducing

In this paper, a new approach for stress-softening of an isotropic, incompressible, hyperelastic and rectangular beam that undergoes cyclic bending-unbending deformation, is presented. Employing an exponential softening function, damage response of the hyperelastic beam due to cyclic finite bending is investigated. The stress-softening phenomenon occurs in elastomeric materials when they deform for

An improved time integration scheme is proposed for linear and nonlinear dynamics. The proposed scheme has two free parameters which control numerical dissipation and accuracy effectively. Basic properties including spectral stability, algorithmic accuracy, algorithmic damping, period elongation and overshooting behavior are investigated. The influences of algorithmic parameters on these properties

Rubbing is an important problem in machinery industry which occurs when a rotating element hits a stationary part. This rotor-to-stator rub may result in the catastrophic breakdown of the machine. In this work, the phenomenon of rotor rubbing is analyzed from the perspective that the signal analysis tools that are in use today to detect this defect emphasize or highlight particular aspects of the studied

Chemically-responsive amorphous shape-memory polymers (SMPs) can transit from the temporary shape to the permanent shape in responsive to solvents. This effect has been reported in various polymer-solvent systems. However, limited attention has been paid to the constitutive modeling of this behavior. In this work, we develop a fully thermo-chemo-mechanical coupled thermodynamic framework for the c

A controlled surface wrinkling pattern has been widely used in diverse applications such as stretchable electronics, smart windows, and haptics. Here, we focus on hexagonal wrinkling patterns because of their great potentials in realizing anisotropic and tunable friction and serving as a dynamical template for making non-flat thin films through self-assembling processes. We employ large-scale finite

Dynamic methods for identifying a model of a nonlinearly elastic deformable body are considered. By the effective phase velocities of longitudinal and transverse waves propagating along and across the axis of the compressed bar, it is possible to determine five elastic constants of the second and third orders included in the model relations. Calculation formulae are obtained and an example of determining

Stenosis can disrupt the normal pattern of blood flow and make the artery more susceptible to buckling which may cause arterial tortuosity. Although the stability simulations of the atherosclerotic arteries were conducted based on solid modeling and static internal pressure, the mechanical stability of stenotic artery under pulsatile blood flow remains unclear while pulsatile nature of blood flow makes

Examination of the flat and curved plates flying close to the ground is an appropriate approach in understanding the complexity of flow behavior near a solid or liquid surface. When a body flies close to a surface, the vortex structure behind the body is changed; therefore, the resultant lift force is more than zero. This phenomenon is named “ground effect”. In this study, flat and curved plates submerged

A new numerical method, verified by the analytical solution of the weight functions and experimental paths, is developed to evaluate the crack initiation and propagation generally in mixed mode (I-II). This numerical method combining the interaction integral method and the maximum tangential stress (MTS) criterion is based on the finite element method of secondary development. The influence of combined

This study presents the analytical modeling of a novel, simple, practical, and environmentally-friendly piezoelectric thermal energy harvester which consists of two main components: a substance exposed to a fluctuating heat source (a solid elastic material or a pressurized gas) and a piezoelectric layer to generate electrical power. Thermal variations resulting from the fluctuating heat source within

This work is focused to investigate the effect of various discontinuities like cracks, inclusions and voids for an orthotropic plate, to evaluate the normalized mixed-mode stress intensity factors (NMMSIFs) by implementing the extended finite element method (XFEM) under uniaxial tensile loading though considering the various numerical examples. The NMMSIFs are investigated with the interaction of crack

To describe the specific behavior of soft biological tissues that can be regarded as incompressible, a strain energy function for fiber-reinforcement materials based on two isotropic and anisotropic deformation invariants is developed and investigated. The anisotropic properties of simple composite materials were initially studied and now extensive hyperelastic modeling is used to analyze the dynamic

This research focuses on generating the plastic collapse load boundaries of a cylindrical vessel with a radial nozzle via employing three different plastic collapse load techniques. The three plastic collapse load techniques employed are the plastic work curvature (PWC) criterion, the plastic work (PW) criterion, and the twice-elastic-slope (TES) method. Mathematical based determination of plastic

Metamaterials (MMs) are composites that are artificially engineered to have unconventional mechanical properties that stem from their microstructural geometry rather than from their chemical composition. Several studies have shown the effectiveness of viscoelastic MMs in vibration attenuation due to their inherent vibration dissipation properties and the Bragg scattering effect. This study presents

Detonation propagation in a confined circular arc configuration of an insensitive high explosive PBX9502 is investigated via numerical simulation in this paper. We introduce a steady detonation wave entering the explosive arc with confinements of stainless steel, and then it undergoes a transition phase and reaches a new steady state with a constant angular speed eventually. The influences of the inner

When a hyperelastic tube is inflated, the inflation pressure has a maximum for almost all rubber material models, but has no maximum for commonly used arterial models. It is generally believed that the pressure having a maximum is a necessary condition for localized bulging to occur, and therefore aneurysms cannot be modeled as a mechanical bifurcation phenomenon. However, recent theoretical studies

This paper proposes a novel composite two sub-step implicit method to effectively solve structural dynamic problems. The main highlight of the new method lies that it is truly self-starting and so avoids computing the initial acceleration vector, but the second-order accurate acceleration output can be still provided. Besides, the new method does not sacrifice other desired numerical characteristics

The slotted disk spring is an important part of ultrasonic motors. Its mechanical properties directly affect the running stability of the motor. In this study, an analytical model is developed to solve the preload problem for slotted disk springs used in ultrasonic motors. The outer conical ring of the slotted disk spring is modeled using the conical shell theory. The inner separated teeth are modeled

To solve the problem of rail crack propagation, inadequate studies mainly use a two-dimensional (2D) model for macroscopic crack analysis owing to the failure of accurately reflecting the contact status between the wheel and rail. In this work, we use ANSYS software to establish a three-dimensional (3D) wheel–rail contact model to clarify the microcracks on the rail tread. The influence of the number

In technical practice, problems associated with material fatigue often arise. These problems can be caused by errors in the stages of design, production or use of the structure, e.g., by incorrect determination of service life, incorrect dimensioning of construction details, incorrect welds, etc. In the case of welds, such issues may be caused due to the fact that the base material is not welded through

A hybrid finite element method is proposed for the heat conduction analysis with variable thermal conductivities. A linear combination of fundamental solutions is employed to approximate the intra-element temperature field while standard one-dimensional shape functions are utilized to independently define the frame temperature field along the element boundary. The influence of variable thermal conductivities

This study investigates the influence of large amplitude vibration on geometrically imperfect sandwich curved panels embedded with gradient metallic cellular (GMC) core using an efficient nonlinear finite element formulation based on higher-order shear deformation theory (HSDT). The cores of the sandwich curved panels are assumed to have three distinct porosity distributions. The material properties

In this paper, nonlinear resonance characteristics of a dielectric elastomer actuator are investigated with special consideration on the thermal effects. A finite thermo-elasticity model based on the Gent model is constructed to analyze the vibrational response of the system. The equation of motion is derived via the Euler–Lagrange method. The multiple scales method and the Taylor series expansion

Computational models provide a powerful tool for pre-clinical assessment of medical devices and early evaluation of potential risks to the patient in terms of plaque fragmentation and in-stent restenosis (ISR). Using a suitable constitutive model for arterial tissue is key for the development of a reliable computational model. Although some inelastic phenomena such as stress softening and permanent

The transient deflections of the functionally graded structure considering various types of patterns (power-law, sigmoid and exponential) are computed in this paper numerically using a higher-order shear deformation model. Also, the model includes variable distribution of porosity, i.e., the even and the uneven types, through the thickness direction (z-axis) of the graded panel. The transient deflection

The force response of poroelastic materials including poroelastic gels to indentation is known to be time- and space-dependent (i.e., a function of indenter shape and size). Despite the complexity of the poroelastic response and in contrast to viscoelastic mechanics, poroelastic mechanics can be captured in terms of several intrinsic mechanical properties, such as elasticity, permeability, and Poisson

For the distribution prediction of fatigue life and residual strength of fiber reinforced polymer composites, the existing models have the disadvantages of imprecision, instability and single applicability. A novel S–N curve model and a residual strength degradation model were first developed, which are independent and uncorrelated. After verifying their reliability, the statistical distribution models

The strong coupling effect of two-phase flow and ice accompanies the ice accretion process of aircraft and wind turbine in damp and cold environment. A method based on the Eulerian two-phase flow, domain discretization of finite volume method (FVM) and finite element method (FEM), and fluid–solid coupling for numerical simulation of ice accretion is presented in this paper. In addition, the icing process

In this study, a bubble complex finite strip method (BCFSM) with the higher-order zigzag theory is formulated for mechanical buckling and free vibration analysis of laminated composite plates, including cross-ply and angle-ply laminates. Few studies have been done to obtain the analytical solutions for clamped and free boundary conditions in the longitudinal and transverse edges. Therefore, this study

This work proposes a gradient enhanced localized radial basis collocation method (GL-RBCM) for solving boundary value problems. In particular, the attention is paid to the solution of inverse Cauchy problems. It is known that the approximation by radial basis functions often leads to ill-conditioned systems due to the global nature. To this end, the reproducing kernel shape function and gradient reproducing

The stress-softening phenomenon, named as the Mullins effect, can widely occur in filled rubbers after cyclic loading and unloading conditions. The reloading curve is typically below the initial loading curve unless the applied strain exceeds the previously applied maximum strain. Experimental observations have also shown that the Mullins effect can be recovered by annealing the pre-deformed filled

A seismic survey is perhaps the most common geophysical technique used to locate potential oil and natural gas deposits in the geologic structures. Thanks to the rapid development of modern high-performance computing systems, the computer simulation technology plays a crucial role in processing the field data. The precision of the full-waveform inversion (FWI) essentially depends on the quality of

We study the electromechanical and electrical behaviors of a PN junction in a multiferroic composite fiber, consisting of a piezoelectric semiconductor (PS) layer between two piezomagnetic (PM) layers, under a transverse magnetic field. Based on the derived one-dimensional model for multiferroic composite semiconductor structures, we obtain the linear analytical solution for the built-in potential

Buckling problems of plates with interfaces caused by step changes in thickness, internal line supports and line hinges under uni-axial and bi-axial in-plane compressive loads are solved by using the matched interface and boundary (MIB) method. In view of buckling problems of plates, new MIB algorithms and their interpolation formulations are developed to deal with various interfaces. A number of examples

A time domain method for identifying random dynamic loads is proposed based on spectral decomposition and regularization, which to some extent makes up for the deficiency of frequency domain methods. The random dynamic loads are descripted with their time domain mean functions and covariance matrix, which can intuitively reflect the statistical characteristics of the loads. Therein the random dynamic

Due to strong nonlinear, unsteady characteristics and the fluid–structure interaction effect, vibration analysis of blades under the excitation of the airflow is still one of the technical difficulties. In this paper, the accurate subsonic aerodynamic force is obtained through numerical simulation, and the aerodynamic coupling model of the rotary blade is established. The distribution of the aerodynamic

Thermal buckling of graphene platelets (GPLs) reinforced sandwich functionally graded porous (SWFGP) plate with temperature-dependent (TD) properties is investigated. The studied plate is composed of two homogeneous face layers and one functionally graded porous core. Two types of porosity distribution with uniformly distributed GPL reinforcement are included. Based on the first-order shear deformation

Cylindrical hydrogels have a wide variety of applications, especially in microfluidics as micro-valves, micro-mixers, and micro-lenses. Main advantages of them can be mentioned as their simple geometry and autonomous functionality due to their responses to the environmental stimuli. In current research, kinetics of swelling, shrinking and force generation of cylindrical temperature-responsive hydrogels

Many experiments have well found that the lifespan of lithium-ion (Li-ion) batteries can be effectively improved by nanoscale structured electrodes. In order to investigate the coupling mechanical and chemical mechanism underlying the superior performance of nanoscale structured electrodes, an alternative diffusion-stress coupling model considering the surface effect of nanomaterials is proposed. The

Twisted and coiled polymer actuators (TCPAs), an emerging class of artificial muscles, exhibit the advantages of large stroke, low hysteresis, low cost, etc. The effect of design parameters on thermal actuation is important for the effective design of TCPAs. In this study, a new model has been developed to describe the effect of geometrical parameters on thermal actuation based on Castigliano’s second