Circular bars are widespread elements in building and mechanical engineering. They allow one to enhance the strength of the multilayer composite materials along with their weight reduction. However, their analytical modeling is developed rather poorly, which creates additional obstacles in their efficient design. The paper presents the results of the exact analytical solution to the plane bending task

A new mathematical model of adhesive joint was developed and experimentally validated, in which the Vlasov–Pasternak two-parameter elastic bed model was used to simulate the stress state of the bonding layer. According to this elastic model, the adhesive layer was regarded as a membrane located in the middle of the adhesive layer thickness, between which and the bearing layers there were elastic elements

The paper presents results of fatigue tests in the tension–compression and tension–tension modes of specimens of 45 steel: smooth specimens and specimens with a blind hole of different diameters of 0.6 and 1.6 mm. The fatigue resistance of specimens with a 1.6 mm hole is higher than that of specimens with a 0.6 mm hole. This is accounted for by the different mechanisms of reaching the endurance limit

The model of multiphase media analyzes the effectiveness of describing thermal expansion and shrinkage of unidirectional polymer composites at their uniform heating by linear law. It is shown that the nature of change in thermal deformation as a function of the composite temperature is similar for an unreinforced matrix, and the maximum absolute value of chemical shrinkage is slightly lower than that

A technique for determination of viscoelastic characteristics of transversal-isotropic fiber composite with isotropic components – viscoelastic matrix and elastic fiber – is proposed. The compositeunity cell consisting of two infinite coaxial cylinders is investigated by the representative element method. The solid and hollow cylinders are used to simulate the fiber and matrix, respectively. Characteristics

Methodical aspects of experimental investigation of brittle materials under local edge loading by scratching the specimen surface with a Rockwell indenter to its edge chipping (S+EF method) are detailed. The edge damage parameter range (fracture distance) had its basis in the literature data on numerical simulation of the stress-strain state in the local indentation zone of the material surface to

The formation and evolution of a deformation relief on the surface of a clad aluminum alloy are examined under cyclic loading. The deformation relief originates on the surface of a clad layer in the form of local plastic strain regions with higher roughness, which characterizes the fatigue damage of the material. Saturation (relative surface area covered with the deformation relief) is a two-dimensional

The optimal design of structures that interact with an aggressive environment is considered on the example of a thin-walled shell exposed to the internal pressure of the aggressive gas. The simplicity of the above research object is related to quite simple equations describing the stress-strain state (SSS) of the structure. Any mathematical model simulating the corrosion damage process includes empirical

Numerical simulation results for the unsteady thermal and stressed states of a nozzle vane under unsteady operation conditions of the gas turbine are presented. The vane and nozzle block duct 3D computer model was constructed. The finite element mesh form, its sizes, and calculation time steps were optimized. The vane and duct contained 1.7 and 3.6 mln elements and 2.3 and 0.8 mln nodes, respectively

Computer-aided design/manufacturing (CAD/CAM) endocrowns are commonly applied to strengthen endodontically treated teeth with too much tissue loss. Monolithic or multilayer structures may be used for this purpose. Restorations made with multilayering technique may mimic natural teeth better. The purpose of this finite elemental analysis (FEA) research was to appraise the impact of different materials

Cellulose nanofiber (CNF) is one of natural fibers, and its Young modulus and tensile strength have been estimated close to 140 GPa and at least 2–3 GPa, respectively. As the homogeneous dispersion method of CNF in polymer matrix, the chemical modification of the CNF surface or solvent exchange process are often used. However, the environmental load of these processes is large, and the chemically modified

The purpose was to evaluate the effect of different adhesive systems on shear-bond-strength between amalgam and resin composite. 48 amalgam specimens were condensed into plastic tubes (4 mm diameter × 5 mm height). The specimens were kept in incubator for 24 h at 37°C, aged by thermal cycling 1000 times between 5–55°C. The specimens’ surfaces were finished with coarse diamond burs and randomly divided

The development of energy-efficient methods of controlling the stress state of metallic materials and welded joints is topical for modern production. One of such methods is electrodynamic treatment (EDT). It is based on the passage of electric current pulses (ECP) through the metal, time-synchronized with an impact load initiated by electrodynamic forces. In this case, an electrodynamic deformation

The paper presents the indentation method for strength assessment of the welded joints in high-strength alloy steels, including base metal, heat-affected zone, and welded joint, in production after application of selected flaw detection methods as a final stage of non-destructive testing methods. Non-destructive testing methods are mainly used to detect defects, their location, size, and nature. The

The strength properties of cast solid-solution high-entropy alloys based on bcc and fcc lattices in the temperature range from -70 to 900°C have been investigated. Melting ingots weighing up to 200 g were carried out in a vacuum-arc furnace MIFI-9 by melting the mixture in an atmosphere of purified argon with a non-consumable tungsten electrode on a water-cooled copper hearth. The X-ray phase analysis

Ground iron and steel slag with excellent performance was prepared using the uniform test design. The influence of the fineness and content of steel slag powder on the fluidity and strength of the powder mortar was studied, the regression equations of fluidity and compression strength of different ages are derived, and the contour map is drawn. Based on the optimized composition, the bleeding and dry

The finite element model of a tubular member under the combined action of axial compression, creep, and axial impact was constructed with the numerical analysis software, to evaluate the core concrete creep effect on the dynamic responses of a steel tubular member in axial compression. In the model, the creep effect of core concrete of different age is equivalent to the change of its elastic modulus

The finite element method is used to to study progressive failure aspects of laminar composite skewed hypar shells with straight edges employing the eight-node isoparametric element in linear and elastic ranges under uniformly distributed static loading. A stiffness decrease scheme is proposed in which the stiffness properties of the failed element are gradually reduced resulting in redistribution

This study aims to establish an effective method for predicting the fatigue life of an automotive wheel in the accelerated dynamic cornering fatigue test. The test was simulated by linear transient dynamic finite element analysis, in which a rotating force of constant magnitude was applied to the moment arm tip to simulate the rotational bending effect on the wheel, with the wheel being fixed. Furthermore

The elastoplastic analysis based on the unified strength theory was performed to evaluate the ultimate bearing capacity of double- and multilayered thick-walled cylinders. The theory provides a new concept and method for the analysis of thick-walled cylinders. The solutions derived herein are widely applicable and can quantitatively account for different tension-compression strength values and mean

Two-dimensional T300 carbon fiber-reinforced aluminum alloy matrix (2D CF/Al) composites were prepared by the liquid extrusion infiltration (LEI) process with the matrices of 6061Al and ZL102 alloys. Scanning electron microscopy (SEM) detected a satisfactory infiltration effect for both composites. The fiber distribution was uniform, and casting microdefects were not revealed. Transmission electron

The scraper is the core of the conveyor and its vulnerable part. The problem of bending fracture of common welding scrapers in actual production is under consideration. SolidWorks and ANSYS finite element analysis software were used to construct the three-dimensional model for simulation analysis, and the existing structure was improved and optimized. The comparison results showed: well-type stiffener

The residual stresses and deformation, in terms of the thermoelastoplastic theory, were simulated with the finite element method using ANSYS 13.0 software for a 5A06 aluminum alloy plate after welding. The butt joint thickness of the plate was 6 mm. A 3D thermomechanical model of the plate was constructed. The dimensions and distribution of residual stresses in the welded structure should be analyzed

Low-cycle fatigue properties and uniaxial ratcheting behavior of a 7050-T6 aluminum alloy were investigated by a non-symmetric cycle stress tests at the normal temperature. The low-cycle fatigue behavior of the alloy was evaluated. The effect of the stress rate, stress amplitudes, and mean stresses on its ratcheting performance was discussed. Considering the ratcheting effect and special working conditions

Different morphology and thinning cases of the weld zone of a 7022 aluminum alloy in friction stir welding were analyzed. Metal plastic flow processes in the contact zone for an aerospace friction stir-joint 7022 aluminum alloy were evaluated. The cross section of the contact zon was analyzed by metallographic and tool microscopes. Then, the plastic flow law of the contact zone was established. Theoretical

The pack boriding process of Fe-based powder compact was carried out at 850 to 1050°C for 3 to 10 h. The microstructure and the thickness of the boride layer were observed by VHX-6000 ultra-depth microscopic three-dimensional microscope. The surface hardness of the boride layer was measured by a Rockwell hardness tester, the phase composition of the boride layer was analyzed by X-ray diffractometer

The effect of the solid solution of second-phase particles on the austenite grain growth behavior at different heating temperatures and holding times of Nb-Ti high-strength IF steel is examined. The experimental results showed that the solid solubility of Nb in austenite increased significantly with temperature, dispersion and fine second-phase particles continued to dissolve in austenite. The pinning

The friction stir joining experiment was performed on a 6061-T6 aluminum alloy sheet 1 mm thick by optimization of different process parameters, and the microstructure and performance analysis of the joint area using a metallographic microscope, friction and wear testing machine, and scanning electron microscope were evaluated. The results show that the crystalline grains in the joint area of the specimen

The fatigue strength deterioration in Ti–6Al–4V specimens impacted by steel sphere was experimentally investigated. Based on the test data of Peterson’s formula and the fatigue notch factor, the relationships linking the fatigue notch factor, fatigue strength, injury notch size, and stress ratio were derived. The effect of the notch dimension, residual stress, and stress ratio on the fatigue strength

The design of the pavement structure can make use of moduli to predict its performance during a preset lifetime. It is essential to study static and dynamic moduli characteristics. The static modulus was derived from the compression rebound modulus of the hot-mixed asphalt. The dynamic modulus was checked against a simple performance tester. The modulus of a cold recycled emulsified asphalt mixture

The effects of friction coefficient, stress drop ratio, the ratio of residual strength to initial stress, and the dip angle of faults on the rupture velocity under hydrostatic pressure condition, as well as the stress distribution on the fault, are investigated using General Particle Dynamics code. The numerical results indicate three distinct regimes of rupture dynamics: (i) slow rupture, (ii) sub-Rayleigh

The texture evolution of modified 12%Cr steel in high-temperature compression was investigated under a 10, 25, 35, and 50% reduction at 1150°C by using Gleeble-1500 D thermal simulation machine. Electron backscattering diffraction analysis showed that the texture of modified 12%Cr steel varied within α, γ, and ε and Goss fibers coexisting to γ and ε , then to α and ε , with the {hkl} <111> orientation

The method of constructing a 2D simulation model based on the real microstructure is developed to simulate the microstructural evolution of materials. Microstructure photographs of two typical metallic materials, 40Cr and TC4, are analyzed by scanning electron microscopy-electron backscattering diffraction. Then, the photographs are converted into digital images and the grain topology information in

The welding process of the lap joint between a 5182 aluminum alloy and a DP1180 two-phase steel sheet (1.2 mm thick) is deeply studied by friction stir welding, defects not revealed, and high-quality welded joints were obtained. The steel plate pressed to 0.2 mm is placed under the aluminum plate. With a large-size friction stir head, the rotational speed was 800 rpm and the welding speed was 50 mm/min

Fiber-reinforced resin-based composite stiffened panels are put in the hygrothermal box at 70°C and 85% RH until moisture absorption reaches balance. Then, the compression experiments on the common stiffened panels and the stiffened panels after moisture absorption are conducted to get buckling and failure loads. Test results are compared to analyze the effect of damage on the carrying capacity of

This paper deals with the classical and Bayesian estimations of step-stress partially accelerated life test model under type-I censoring for the inverse Weibull lifetime distribution. In classical estimation, the maximum likelihood estimates of the distribution parameters and the acceleration factor were obtained. In addition, approximate confidence intervals of the parameters were constructed based

When employing end milling for the thin-walled elements, in particular aircraft gas-turbine engines, it is possible to observe their forced vibrations due to the machining discontinuity. The authors present the calculation method for determining the best performance of discontinuous milling of the given elements, which minimizes the forced vibrations’ level and provides the required quality of the

This paper proposes an analytical model for the stress-strain state in a welded joint with a hard single-V butt weld. Analytical expressions for the stress-strain state in both the hard weld and the mild main material subjected to elasto-plastic deformation are proposed. In order to verify the proposed expressions, a finite element simulation of the stress-strain state in a welded joint with a hard

Based on experimental studies of specimens of 12Kh18N10T stainless steel under a rigid (strain-controlled) deformation process, which includes a sequence of monotonic and cyclic loading modes, some features and differences between isotropic and anisotropic hardening under monotonic and cyclic loading are found. To describe these features in terms of the theory of plasticity (the Bondar model), the

A method is examined that permits the ballistic coefficient (BC) of a bullet to be converted based on universal expressions: in the Ciacci law and the air drag law of 1943, i.e., within the framework of laws that extend to the territories of the former USSR countries; to the standards G7 and G1, i.e., within the framework of standards that are the most-used worldwide; in the air drag law of 1943 and

Experimental results are presented for damage accumulation in 10GN2MFA and 15Kh2MFA steels studied with the LM-hardness method at different stress states under cyclic loading at room and elevated temperatures that are consistent with the service conditions of structure elements. Damage accumulation kinetics is examined at primary and secondary creep stages in view of the multiaxial stress state and

The use of a damping system is one of the seismic protection systems that improve the seismic response of structures. The proposed methodology estimates the location (which bay and which floor) where the dampers must be placed to dissipate the maximum energy. The goal is the cost reduction comparing the optimal place to a uniform damper placement (one damper per floor). The historical analysis of two

The paper presents a procedure for determining the design parameters of multilayer thick-walled structures with a local load on the inner surface portion located near the end face. The design provides for the use of two layers, of which the outer layer can have a smaller height. The procedure involves obtaining numerical results of calculating the stress state of the inner cylinder, their approximation

The fracture resistance of domestic and foreign nanolaminate ceramics was studied by the EF (edge fracture) method. This method provides for indentor chipping of rectangular specimen edges, which permits evaluating such fracture resistance characteristics, as chipping resistance and edge toughness. There is no way of experimental determining the stress intensity factor effected as the penetration of

In the present study, closed-cell aluminum foams of varying porosities (65–75%) were produced through the stir casting technique using TiH2 (1 wt.%) as a foaming agent. Under the uniaxial compressive loading, the compressive stress-strain responses of these foams were examined. The finite element (FE) models of the foam were elaborated using the ABAQUS FE simulation software and realized via the ABAQUS

Results of experimental investigation of mechanical characteristics of ULTEM 9085 thermoplastic, produced by additive manufacturing, i.e., the method of layer-by-layer application of a molten polymer thread, are presented. Flat specimens were tensile tested within the temperature range of (–40) –150°C. Temperature dependencies of ultimate strength, relative elongation at break, elastic modulus, and

The statistical analysis performed on the defectiveness of rails in the Kiev subway railway shows that the main cause of the occurrence of most defects is the contact fatigue of the rail material. The paper presents modern concepts of crack growth in the railhead. It has been found that one of the most promising directions of studying the stress-strain state of rails and the crack growth process is

The procedure for the material damage assessment by the LM-hardness method, consisting of the in-service scratching of structure element surfaces and employing portable instruments for its implementation, is described. These instruments can provide the rapid analysis of damage of a structural element to be diagnosed, continuous measurement of axial displacements of the embedded scratching tip, moving

The fretting fatigue behavior in Al–Zn–Mg alloy is investigated under conditions of various equivalent stress amplitudes of cyclic multiaxial loadings and the same contact pressure with a point contact. The ANSYS finite element analysis is used to analyze stress distribution by a numerical study using the 3D finite element method. Fretting regions’ morphology and fracture of specimens are characterized

The effect of hydrogen at a pressure of up to 35 MPa and a content of up to 29 ppm on the strength, ductility, short-term and long-term static crack resistance of four KhN43MBTYu (EP-915VD) alloy modifications with different heat treatment modes and chemical composition has been studied. It has been found that the critical stress intensity factor KIc in the presence of hydrogen, just as the ductility

The authors present the results of experimental investigations of strength and plasticity characteristics, as well as fracture nature, of the specimens of different steels under tension after ion nitriding in hydrogen (nitrogen with hydrogen) and hydrogen-free (nitrogen with argon) environments. The obtained characteristics are compared with those before nitriding. It is established that during ion

Special features of computational assessment of dimensional change of WWER-1000 reactor core baffle during the reactor operation are discussed. The paper gives results of computational analysis of a change in shape of core baffle, which was performed by applying up-to-date approaches of modeling the irradiation-induced swelling of constrained austenitic steels under the action of neutron irradiation

The following correction should be made to the article entitled “Milling-Related Brittle Fracture Mechanisms of a SiCp/Al Composite” by H. J. Zhang, J. G. Li, and J. G. Du, Vol. 52, No. 1, 81–89, 2020, https://doi.org/10.1007/s11223-020-00152-3.

The spatial axisymmetric creep problem for complex-shaped bodies of rotation from functionally graded materials is considered. For the variational problem statement, the Lagrangian-form functional is defined for kinematically possible displacement rates. For the main unknown creep parameters, namely displacements, stresses, and strains, the Cauchy problem in time scale is formulated for the spatial

In this article, a constant-stress partially accelerated life test model of high reliability products and materials with type-II censored data from the linear failure rate distribution is considered. Two different methods of estimation likelihood and Bayesian are used to estimate the unknown parameters of the model. The maximum likelihood estimates of the model parameters are obtained using the Newton–Raphson

The effect of contact conditions and the gap between the metal and composite layers on the stress-strain state and strength of a two-layer metal composite cylinder under internal explosive loading in air is numerically studied. It is accepted that in the absence of a gap between the metal and composite layers, there is no interference. The problem was considered on the basis of the general equations

Limiting cyclic stress diagrams of welded joints of a low-carbon and low-alloy steels of different strength levels are analyzed under conditions that they contain the same level of steady residual stresses. For tests of butt-welded joints as an example, a procedure for calculating the endurance limit at different values of limiting steady residual stresses is proposed. Limiting cyclic stress diagrams

A system for recording the contraction of cylindrical specimens under static compression loading was developed based on the original cantilever-type extensometer and the L-Card E-440 analog-todigital converter with Power Graph software for data acquisition and pre-processing. 26H2MF and St12T steels’ stress–strain diagrams in compression at elevated temperatures were constructed. The influence of temperature

Structural features, mechanical properties, and stressed state of welded joints of the TiAl system intermetallic compound (Nb, Cr, Zr) after electron-beam welding and subsequent electron-beam local heat treatment are determined. It was shown that stresses generated immediately after welding contributed to the appearance of cold cracks in the weld. Residual stresses in welded joints were determined

The paper considers one of the topical problems of the targeted control of the properties of the material of products in the zones under critical loads, which lead to their failure or loss of performance. The processes for the diffusion saturation of the surface layers of parts (chemical heat treatment) are an effective method for the strengthening treatment of parts of complex geometric shape. The