The goal of this study was to examine the fracture behavior of advanced high strength steel (AHSS) sheets in bending. For this purpose, 3-point bending (3 PB) tests were conducted on DP980 and TRIP1180 sheet samples. The test specimens were prepared in different orientations with respect to the rolling direction of the sheets. The onset of fracture and fracture strains were determined through digital

The small punch test consists on punching a plane small specimen until it breaks. This technique, born in the 80’s, should be considered when evaluating mechanical properties in situations where materials are in shortage. In recent works, it has been used to estimate the mechanical properties of steels in aggressive environments, where characterizations usually consist on the determination of the threshold

This study demonstrates the applicability of peridynamic unit cell (PD-UC) for predicting effective thermoelastic material properties of complex microstructures, and reduction in moduli due to the presence of defects. The comparisons for six different microstructures (i.e. Hexagonal pack, three-phase interphase, 0/90, spherical inclusions, woven-fiber, and random short-fiber) show remarkable agreement

This research presents the crack coalescence mode and physical field evolution characteristics of a brittle material containing two 3-D parallel embedded flaws. A numerical model based on the flat-joint model is established and validated by laboratory experiments. The crack coalescence modes of two 3-D parallel flaws with different geometries are summarized. The physical field evolution characteristics

To study the time-varying dominant frequency distribution characteristics during the cracking process of intact and flawed rocks, uniaxial compression tests are carried out on three types of red sandstone specimens. Both acoustic emission (AE) and photographic technologies are performed to monitor the real-time cracking process of tested specimens. The relationship between the AE rate curve, the axial

Our engineered metallic materials are being designed to be more and more ductile with an increase in strength. Consequently, the failure mode has changed – from brittle to ductile fracture, which leads to a limited applicability of the previously used parameters that quantify the material resistance developed for brittle fracture. This is owing to that a considerable amount of plastic strain is introduced

This paper studies an axisymmetric problem of a penny-shaped crack at the interface of a bi-material under a static torsion by an embedded circular rigid disc. By using the Hankel integral transformation method, the angular displacements and the shear stresses are formulated. The faces of the crack are supposed stress free, and the displacement is continuous outside in the crack plane while the rigid

Combining the advantages of the size and the boundary effect models, an improved fracture model for determining the material parameters of concrete is proposed in this paper, considering concrete aggregate grading. The simple method for determining the fictitious crack growth length at peak loads of concrete specimens is identified through quantitative research. The independent fracture toughness and

Many industrial components made of cast aluminum alloys are subjected to multiaxial loadings, while most of research on these materials are on uniaxial loading condition. This article investigates the fatigue performance of A356-T6 aluminum alloy produced by high pressure die cast (HPDC) under different loading conditions. In addition to obtaining monotonic and cyclic deformation behaviors, fatigue

This study aims to model delaminations in laminated composite beams by using the PeriDynamic Differential Operator (PDDO) and Refined Zigzag Theory (RZT). A cohesive zone model is employed to monitor the delamination evolvement in laminated composite beams by embedding an interfacial resin layer between two potentially separable material layers. PDDO calculates the local derivatives in their nonlocal

This paper discusses the thermal fracture analysis of anisotropic materials under thermal shock based on the classic theory of thermoelasticity in the framework of the Extended Finite Element Method (XFEM). A new set of tip enrichment functions for the temperature field in anisotropic materials is proposed. To this end, an analytical solution for the temperature distribution around an insulated crack

It is well known that making of specimens, experimental set up, fixtures and testing procedure could inevitably affect the experimental accuracy, which will actually induce the disturbance from weak Mode-II loading on the specimen in K-based Mode-I fracture toughness tests. How to quantitatively analyse the disturbance effects is quite interesting and challenging work. In present article, an energy-based

Rock mass engineering in a high-temperature environment is often affected by complex stress conditions. In this paper, to reveal the damage characteristics and fracture behaviors of granite after high temperature exposure under different strain rates, twenty-four uniaxial compression tests were carried out on granite specimens under the combined action of six temperatures (25 °C, 200 °C, 400 °C, 600 °C

The welding residual stresses (WRSs) in an orthotropic steel deck were investigated via experimental measurement and finite-element simulation. Both the surface and through-thickness WRSs were obtained. The simulated residual stress fields were in reasonable agreement with the measured results. The weight function method (WFM) was then adopted to investigate the effects of WRSs on stress intensity

The influence of different harsh environmental conditions on the fracture behaviour of secondary bonded adhesive joints is experimentally investigated using mode I DCB tests. Two types of adhesively bonded joints under wet-aged and non-aged conditions were tested at three temperatures: −55 °C, room temperature and 80 °C. The wet-aged specimens were exposed to accelerated ageing in an environmental

There is a need for numerical models capable of predicting local accumulation of hydrogen near stress concentrators and crack tips to prevent and mitigate hydrogen assisted fracture in steels. The experimental characterisation of trapping parameters in metals, which is required for an accurate simulation of hydrogen transport, is usually performed through the electropermeation test. In order to study

This experimental study shows the conjunction of fracture mechanics with the ability of high-performance concrete (HPC) to resist an aggressive chloride environment. Moreover, the influence of a chloride-contaminated environment on the fracture toughness and fracture resistance under the mixed mode I/II is presented. The experimental study was performed considering different aggressivity levels of

The phase field fracture method has emerged as a promising computational tool for modelling a variety of problems including, since recently, hydrogen embrittlement and stress corrosion cracking. In this work, we demonstrate the potential of phase field-based multi-physics models in transforming the engineering assessment and design of structural components in hydrogen-containing environments. First

In this study, we examine the fracture analysis of a non-homogeneous half-layer reinforced by a magneto-electro-elastic (MEE) coating with multiple interface and embedded cracks in a non-homogeneous substrate under impact loadings. Material properties of the functionally graded (FG) orthotropic substrate are assumed to vary exponentially in the thickness direction of the half-layer. First, the analytical

The crack and the rigid-line inclusion problems under the anti-plane shear are the special case of the elliptic hole and elliptic rigid inclusion, respectively. We revisit this kind problem by using the degenerate kernels in terms elliptic coordinates. The stress intensity factor (SIF) is also addressed. Three ways are employed to determine the SIF. One is the extrapolation approach for the boundary

Ordinary state-based peridynamics (OSPD) is a promising computational method to analyze damage and fracture process because its equation of motion is still satisfied at the presence of discontinuities. Though OSPD has been introduced to evaluate mesoscopic behavior of concrete, there are many unsolved issues to tackle quasi-brittle behavior of mesoscopic constituents. In this paper, an improved mesoscale

In this work, epoxy alumina nanocomposites were synthesized with Al2O3 nanofiller by instant cross-linking process. Two different particle morphologies (viz. rod and spherical shape) were selected as filler to investigate their effect along with wt.% (0.5, 1.0, and 1.5 wt%) on the fatigue behavior of epoxy alumina nanocomposites. Stress to number of cycles to failure (S-N curve) as per ASTM D 7791

Shear failure of rock masses along discontinuities is one of the dominant failure modes of underground tunnels and rock slopes. In this paper, the shear fracture evolution and failure mechanism of rock-like materials containing cross-flaws are first reported based on a developed CZM-FEM method. The laboratory uniaxial compression and corresponding numerical tests were initially performed to acquire

Stiffened panel with multiple site cracks has been a great concern in the aviation industry and academia. In this paper, an analytical method for solving the stress intensity factor and strip yield model with coalesced plastic zone is developed based on the superposition principle, displacement compatibility and weight function method. It is then applied to obtain the stress intensity factors and plastic

The finite element method was used to quantify the change of the crack driving force for mode I crack propagation in thin copper (Cu) films towards the interface with silicon (Si) substrate. Both elastic-elastic and plastic-elastic transitions at the Cu-Si interface were considered. The plasticity of the thin Cu film was modelled for different material behavior (elastic-ideal plastic, bi-linear and

In this paper Small Punch Tests (SPT) are used to determine the mechanical properties of the heat affected zone (HAZ) of CrMoV welded joints and to evaluate the embrittlement caused by the presence of internal hydrogen. Hydrogen permeation tests were carried out to determine the effective diffusion coefficients of the different regions of welded joints, whose hydrogen contents were measured using a

This study aims at introducing generalized fracture solutions for 3-D radial semi-elliptical surface cracks contained in rotating hollow disks to the literature. Normalized mode-I stress intensity factors (SIFs) are presented for a wide range of cases that involve different values of crack aspect ratio, depth, radial coordinate and geometric parameters of the disk. By leveraging the obtained numerical

This study presents a fatigue model for constant and variable amplitude cyclic loading by combining kinetic theory of fracture (KTF) with peridynamics (PD). The KTF is applicable to constant and variable amplitude loading, and cumulative damage is inherent in the assumptions. Also, it is extremely suitable for implementation in the PD model of laminates. The standard stress versus cycles to failure

Experimental studies on various strengthening systems for steel elements under fatigue loading showed that the use of carbon fiber reinforced polymer (CFRP) strengthening system could significantly enhance the fatigue lifetime. Besides, more recently it was shown that the use of prestressed unbonded CFRP strengthening system results in an additional reduction of the fatigue crack propagation rate and

A new analytical method for calculating the Stress Intensity Factor (SIF) under Mode II loading is presented in the framework of two-dimensional stationary elasticity. Starting from the linear elasticity equations, the crack problem is formulated as a system of Hamiltonian equations, solved based on a new method for determining eigensystems, called Exponential Matrix Method (EMM). The obtained eigensolutions

In this paper, a J-integral formula and numerical calculation method are presented, which confirm the path-independence of a J-integral, considering the mixed-mode fracture in a chemo-mechanical coupled medium. The Jk-integral denotes a two-dimensional vector consisting of the components J1 and J2. Using the Equivalent Domain Integral (EDI) method, the chemo-mechanical coupled J2-integral, with an

This paper presents the application of the weight function method for calculating the stress intensity factors for high aspect ratio semi-elliptical surface cracks in finite thickness plate subjected to arbitrary two-dimensional stress fields. Based on the formulation initially proposed by Wang and Glinka (2009), an extended 2D weight function for surface cracks with aspect ratio 1.0 ≤ a/c ≤ 8.0 is

In this study, several Mg-9%Al-2%Ca alloy round-bar specimens were fabricated by the selective laser melting (SLM) process. A fraction of the specimens was submitted to tensile testing. Then, the remaining fraction of specimens were drilled and subsequently submitted to further tensile testing interrupted at 90% of the ultimate tensile strength (UTS). Fracture surfaces were analyzed and an Electron

The presence of interstitial hydrogen in steel produces embrittlement, which poses a severe risk to the integrity of structural components. Although real steel, as a multi-phase material with crystal defects at several scales is too complex a system to be modelled utilizing ab-initio calculations, mechanisms of hydrogen (H) diffusion in metals have attracted interest and have been widely described

A method is developed for solving the transient problem of the sudden appearance of an infinite row of parallel cracks in a stretched medium of saturated porous material. The general equations of Biot’s theory in conjunction with the integral and Laplace transforms are used to reduce the problem to that of solving the Fredholm integral equation. The numerical results in terms of the Mode I dynamic

In this paper, a functionally graded (FG) hollow cylinder with fully multiple longitudinal cracks is analyzed using the weight function method (WFM). The cylinder's inner surface is made of Al2O3, while the outer surface is made of TiC. The distribution of material properties is continuously due to the power-law function. The cracks placed in such a way to have identical angles relative to each other

It is vital to prevent brittle cracks in large structures. This is particularly important for a number of industry sectors including offshore wind, Oil & Gas, and shipbuilding where structural failure risks loss of human life and loss of expensive assets. Some modern steels exhibit high Charpy energy – i.e. high initiation fracture toughness, but poor resistance to crack propagation – i.e. low crack

In this paper, the effects of thermal stress on AP1000 reactor pressure vessel (RPV) is analyzed, and the elliptical corner crack propagation at the nozzle-cylinder intersection is investigated. The corner crack stress intensity factor (SIF) is computed under static pressure and combination (static pressure plus thermal stress) loadings and crack propagation. The analysis reveals that with an increase

Having asphalt in Cement Emulsified Asphalt Mortar (CEAM), this composition has higher toughness and ductility but also higher thermal sensitivity than conventional cement mortar. This study was aimed at investigating the fracture behavior of CEAM under out-of-plane shear and tensile loadings (Mode I, I/III, III) at low temperature. This investigation was performed by testing Edge Notched Disc Bending

The correlation between the out-of-plane stress and the in-plane stress is established based on the bending modified J-Q theory and the out-of-plane constraint parameter TZ. Accordingly, an improved J-QZ-M constraint theory is developed to characterize the crack-tip fields by taking into account opening- and bending-dominated deformations in the ligament of the clamped single edge notch tension (SE(T))

Fracture loads of engineering components with blunt notches cannot be evaluated by the linear elastic fracture mechanics (LEFM) due to no stress singularity. In this study, an approach to determining stress fields and notch stress intensity factors (NSIFs) at blunt V-notches is developed using the photoelastic technique. To solve the nonlinear governing equations of the NSIFs derived from the Filippi’s

A new development has been proposed to measure the tensile fracture toughness (KIc) of rocks. An innovative configuration of chevron notch was applied acting as a cracked chevron notched direct tension (CCNDT) method to determine the mode I fracture toughness, which also could be suggested as a direct method to specify the tensile fracture toughness. In this method, the initial crack is generally created

The overall characteristics and fracture behavior of asphalt pavements and overlays is significantly controlled by the mechanical behavior of bitumen used in the mixture of asphalt concrete. The bitumen behaves like a dominantly brittle and elastic medium under subzero temperatures. In practice, cracked asphalt pavements experience mixed mode tensile-shear deformations due to moving traffic loads or

Fatigue assessment of welded assemblies is a key challenge both for industrial and academic research. This paper assesses possibilities of thermoelastic coupling quantitative analysis for the comprehension of fatigue phenomena occurring with welded structures. A test protocol has been set up to measure temperature field on cruciform as-welded specimens under cyclic loading thanks to an infrared camera

It is critical to study the fracture behavior of alkali-activated slag columnar coral aggregate concrete (ASCCAC), especially under ocean environment. Furthermore, it is necessary to also consider the microstructure of the specimens and fictitious crack growth. Thus, this paper is mainly aimed at evaluating the effects of average grain size (G = 6 mm, 7 mm, 8 mm) on the fracture properties of ASCCAC

Fatigue life and crack growth retardation due to spectrum loading, which are superposed on constant amplitude cycles, have been investigated in this paper. For this purpose, numerical and experimental methods are used to investigate the behavior of fatigue crack growth in the rail specimens. A 3D nonlinear boundary element model has been applied to estimate the fatigue life of the rail specimens. Then

In this paper, dual boundary element method (DBEM) is combined with interaction integral (I-integral) to evaluate stress intensity factors (SIFs) and T-stress simultaneously for mixed-mode crack analyzing. DBEM is proved to be one of the most efficient boundary element methods (BEM) for solving crack problems with boundary-only discretization, however its current implementation is in lack of efficient

Comparison of the microstructure and the phase composition of the Ti-6Al-4V alloy parts built by various additive manufacturing technologies was carried out by optical and transmission scanning electron microscopy, as well as X-ray diffraction analysis. It was shown that the martensitic αʹ phase, formed due to the melt pool fast cooling rate, determined the accommodation mechanisms of shear deformation

This work presents atomic simulations of crack tip behavior in HCP titanium single crystal with center crack under mode I loading condition. The simulation results show that the crack tip plasticity in most of the studied crack orientations is attributed to the activation of basal or prismatic 〈a〉 slips, which is in accordance with the slip characteristics analysis. Comparing the increment of crack

In this paper, a systematic study on the effect of flaws on flexural strength of ultra-high temperature ceramics (UHTCs) was carried out by using three typical materials (i.e., ZrB2, ZrB2-SiC and ZrB2-SiC-G ceramics) containing micro-sized flaws with controllable sizes, shapes as well as orientations. Depending on the flaw sizes and orientations, different fracture modes were analyzed by SEM observation

In this paper, the crack initiation angle is studied experimentally and theoretically in sharp V-notched specimens subjected to mode I loading. Some experiments are performed on the V-notched compact tension (CT) and double cantilever beam (DCB) specimens made of polymethylmetacrylate (PMMA) with two different notch opening angles. It is demonstrated that although symmetry exists in both geometry and

Rock mass containing natural fractures is susceptible to freeze-thaw (F-T) weathering in cold regions and could result in the instability of rock engineering and even serious geological hazards. Yet the F-T action on the change of fracture physical characteristics and the associated fracturing evolution of naturally fractured rock is poorly understood. In this work, multi-level compressive cyclic loading

Vibration based damage detection usually faces two fundamental problems, namely the low sensitivity to the relatively small but potentially dangerous damage, and the dependence of vibration characteristics of structures on ambient factors (primarily temperature). Indeed, the effect of ambient factors on the vibration characteristics may be more significant than the influence of damage. In such situations

Quasi static crack growth of Al/Al2O3 functionally graded materials prepared through powder metallurgy up to 30% weight fraction of Al2O3 is studied with crack on stiff (FGM I) and compliant (FGM II) sides using crack gauge in three point bend test. The variation of weight fraction of Al2O3 with distance from 100% aluminum face is measured through image analyzers to identify the composition corresponding

In the current work, the interlaminar fracture behavior of carbon fiber-Al laminates (FML) was investigated in mode I using double cantilever beam (DCB) specimen with a modified sub-layers sequence of Al/[C]02/Al/[C]02. Various microcapsules comprising hollow capsule and core–shell microcapsules were synthesized, and the integration effect of different microcapsules on the interlaminar delamination