Abstract In this work, the interphase in polymer nanocomposites is modeled as a multilayered part in which the Young’s modulus of each layer Ek continuously changes from nanoparticle surface (xk = 0) to polymer matrix (xk = t). The dependency of Ek onxk is analyzed by linear, exponential and power functions. The average interphase modulus is determined by the Ji model for several samples and the accurate

Abstract This paper numerically investigates the mechanical behavior of an aluminum specimen with a TiC–Al6061 composite coating. The strain localization and fracture patterns are determined for different scale levels. The effects of the loading type, distance between titanium carbide particles, and metal matrix coating thickness are studied. A numerical method based on the experimental data is proposed

Abstract Control over the inelastic deformation of polycrystals aimed at achieving desired performance characteristics of finished products is impossible without analyzing the structural evolution of the material at different scale levels. A major task in this respect is to develop physically sound mathematical models for describing the internal structure evolution as it determines the material properties

Abstract A closed system of differential equations has been derived to describe thermal processes in a one-dimensional harmonic crystal on an elastic foundation. It is shown that the evolution of thermal perturbation in such a crystal is described by a discrete unsteady-state equation, a special case of which is the hyperbolic equation of ballistic heat conduction. This equation remains valid with

Abstract This work suggests a modeling method based on micromechanical models such as Pukanszky one to determine the interphase properties in ternary polymer nanocomposites containing two nanofillers. The developed models can calculate the volume fraction, thickness and strength of interphases between nanoparticles and polymer matrix using the experimental data of Young’s modulus and yield strength

Abstract Attempts to improve the osteointegration, fixation and stability of Ti-base implants have been focused by producing a significative surface roughness that enhances the surface area available for bone/ implant apposition. In this research study, it shows the experimental data by synchrotron radiation X-ray diffraction (SR-XRD) of the main material surface properties (residual stress and cold

Abstract The paper analyzes the scale hierarchy of transitions from very high to high and low cycle fatigue which are taken as fatigue limit according to the Wöhler concept. The analysis shows that the life distribution in the transition range 106–108 cycles is multimodal. From relations between the fatigue limit σ–1 and mechanical characteristics σU and σ0.2 in aircraft materials based on Fe, Al,

Abstract In this article, the generalized model for photothermal wave under dual-phase-lag model is utilized to compute the increment of temperature, the components of displacement, the carrier density and the stress components in a two-dimension semiconducting media. By using Fourier and Laplace transformations with the eigenvalue techniques methodology, the exact solutions of all physical quantities

Abstract The present paper deals with the development of dense Fe–Ag and Fe–Cu high-strength nanocomposites from blends of nanocomposite powders employing cold sintering (high-pressure consolidation). Nanocomposite powders were obtained by high-energy attrition milling of micron-scale powder of carbonyl iron (Fe) and nanosized silver oxide powder (Ag2O) as well as of nanopowders of Fe and cuprous oxide

Abstract The paper proposes a finite element approach with a mathematical model and an algorithm for simulating the wear of polymer composites in friction joints with account of temperature. The polymer interaction with a counterpart is modeled by solving a stress-strain contact problem with regard for the physical nonlinearity of deformation in polymer composites. The contact temperature is estimated

The use of NiBrAl casting alloy for the construction of marine propellers is expanding due to the resistance to fatigue, corrosion and wear under the effect of particles suspended in fluid. In this study, the nanostructure of the Ni-B coating is created by the electroless plating method on the NiBrAl alloy surface. After plating, the specimens are heat-treated, and the temperature and optimum time

A simple methodology is suggested to examine the roles of interphase characteristics in the shear, bulk and Young’s moduli of polymer nanocomposites containing spherical nanoparticles such as SiO2 and CaCO3. A core-shell structure is presumed for nanoparticles and surrounding interphase, and then the shear and bulk moduli of supposed particles are calculated. Subsequently, simple equations predict

This paper presents a higher-order shear and normal deformation theory for the static problem of functionally graded porous thick rectangular plates. The effect of thickness stretching in the functionally graded porous plates is taken into consideration. The functionally graded porous material properties vary through the plate thickness with a specific function. The governing equations are obtained

A new hybrid discrete-continuum cellular automata approach is proposed to simulate the process of new phase/grain nucleation and growth. The method couples classical thermomechanics and the logics of cellular automata switching. Within the framework of the hybrid discrete-continuum cellular automata method, the space occupied by the simulated specimen is represented as a cellular automaton—a set of

The prime objective of the present paper is to analyze the propagation of thermoelastic waves in a homogeneous isotropic elastic semi-infinite space that is exposed to a magnetic field at initial temperature T0 and whose boundary surface is subjected to the moving heat source and load moving with finite velocity. Temperature and stress distribution occurring due to heating or cooling have been determined

The stochastic structure of polycrystalline materials causes a high inhomogeneity of the kinematic and force fields in grains of materials and large fluctuations of these fields. The inhomogeneity and fluctuations are insignificant in some cases, but they become crucial in the study of various critical phenomena whose occurrence strongly depends on the type of material microstructure. Fluctuations

In this paper, we report the experimental data of the elastic properties of the Young’s modulus and shear modulus based on the variation in the ultrasonic velocity parameter during the microstructural evolution in a Ti-6Al-4V alloy with two—bimodal and Widmanstätten—varying microstructures. The two different initial microstructures were treated thermally by aging at 515, 545, and 575°C at different

Real mechanical assemblies favor the initiation and propagation of fatigue cracks due to stress concentration phenomena arising from the geometrical features such as notches, corners, holes, welding toes, etc. Classical fatigue analysis of notched specimens is done using an empirical formula and a fitted fatigue strength reduction factor, which is experimentally expensive and lacks physical scene.

In this work, the current state of understanding of grain structure evolution during friction-stir welding is briefly reviewed. The broad aspects of this process and experimental techniques for its examination are critically addressed. The specific character of the microstructural evolutions in body-centered cubic, face-centered cubic and hexagonal close-packed metals are considered in details. In

Thrust faulting has been studied within the framework of a tectonic wedge model. A variant of the model was proposed which accounts for changing friction between the wedge bottom and a rigid foundation during irreversible deformation. Some specific deformation structures typical for thrust zones were revealed; their formation conditions were estimated. The range of friction coefficient values was determined

In the work, we develop and implement force and deformation models of the strain and damage accumulation rates in creep with the use of the ANSYS finite-element analysis software. Numerical calculations are performed on a plane plate with a rectilinear through crack under biaxial loading and on a three-dimensional compact specimen under eccentric tension. The obtained stress-strain fields are used

Inclined multiple cracks may appear in composite laminates and sandwich structures. In this paper, we solve the fracture problem of a three-layer sandwich structure which contains multiple inclined cracks in the central layer under tension and antiplane shear. Three types of crack configurations are considered: an isolated crack, a periodic array of inclined cracks with the same length, and two parallel

The problem of the strength of a plate made of a brittle material with through mode I cracks is discussed. In contrast to the approach based on the singular solution of the classical theory of elasticity for a plane with a crack and on linear fracture mechanics, we propose to use nonsingular solutions obtained within the generalized elasticity theory and, as a result, to implement a method, conventional

The paper analyzes the microstructure and phase state of magnetron-sputtered nanocomposite Ti-C-Ni-Cr coatings based on Ni- and Cr-doped amorphous carbon by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. The analysis shows that the coating structure comprises an amorphous carbon matrix and nanosized TiC and Ni particles with relatively low lattice bending-torsion

The paper studies the effect of the annealing temperature on microstructural transformation and micro-hardness variation in an internally oxidized vanadium alloy V—Cr—ZrO2 deformed by high-pressure torsion in Bridgman anvils. It is shown that the development of large plastic strains and subsequent annealing of the particle-reinforced V—Cr—ZrO2 alloy lead to the formation of a fine-grained structure

The paper analyzes the applicability of available nonlocal and gradient fracture criteria to brittle, quasi-brittle, and ductile fracture in notched materials. All chosen criteria use an internal size parameter as a material structure characteristic, which makes it possible to describe the scale effect under stress concentration and to extend the range of their application compared to conventional

The paper discusses fracture processes occurring under compressive loads. The processes are considered from two points of view: (i) compression fracture mechanisms and their effect on the strength and fracture resistance of the material, and (ii) the effect of geometric constraints on the stress-strain state and fracture conditions of bodies (natural objects) with cracks and crack-like defects. These

The paper proposes a Lagrangian formalism for describing the space-time dynamics of complex continuum motion with addition variables—non-Eulerian dynamic degrees of freedom. The new variables are interpreted in terms of mechanics and geometry, and principles are suggested for their tracking in experiments. The formalism offers invariant tensor representations of Lagrangians in a system with an extended

A new concept in mechanics is proposed based on the notions of space, time, and energy. The energy is represented by the sum of thirteen terms expressed as products of invariants of the Lagrangian equations of motion and scalar factors corresponding to the physical properties of materials. Differential equations of motion and equilibrium are derived from the frame indifference condition for energy

In the paper, inelastic strain localization in homogeneous specimens and mesovolumes of a polycrystalline material is modeled based on the asymmetric theory of an elastoplastic Cosserat continuum in a two-dimensional formulation for plane strain. It is assumed that rotational deformation in loaded materials occurs due to the development of localized plastic deformation as well as bending and torsion