The fracture assessment of additively manufactured PLA and graphene reinforced PLA (PLA-GR) has been performed in this paper. Tensile and fracture specimens were fabricated with three different raster orientations (0/90, 30/-60 and 45/-45) in order to analyse the effect of the printing strategy on the resulting mechanical properties. A total of 30 tensile tests and 120 fracture tests were performed

To explore the deterioration response of rock engineering structure under seasonal acid rain, a large number of mixed mode I-III fracture experiments were conducted on sandstone with the edge notched disc bending (ENDB) specimens. Before fracture tests, all the sandstone samples were respectively subjected to 0, 2, 4, 7 and 10 wetting-drying cycles with hydrochloric acid solution to simulate the periodic

This paper proposes an effective FE modeling for simulating fracture propagation in linear elastic media under mechanical and thermal loadings. The model joins Moving Mesh (MM) technique with Interaction integral (M-integral) method to simulate crack advancing phenomena. MM reproduces growing cracks by moving the mesh nodes around the crack front, according to proper fracture criteria. In particular

Crack paths in ferroelectrics under combined electromechanical loading have been investigated both experimentally and numerically in the past. The influence of electric fields on the deflection behavior being of particular interest, specimens exhibiting a pronounced curvature of crack growth have been predominantly considered. In this regard, a series of three-point bending tests with eccentric notch

Most studies of thermal effects on rock fracture have focused on Mode I, while the temperature-dependence and loading rate effect on Mode II fracture are rarely involved. We present the static and dynamic punch-through shear (PTS) tests, implemented on the INSTRON 1342 and the modified split Hopkinson pressure bar (SHPB) system respectively, as the approaches for determining the Mode II fracture toughness

This paper addresses a physical damage model and continuum damage-based fracture simulation procedure for simulating crack initiation, growth and cracks coalescence of quasi-brittle geomaterials. The model is proposed by using the principle of minimum dissipative energy combining with Drucker-Prager criterion, in which every parameter of the damage model has clear physical meaning. The procedure coupled

This paper aims to analyze the discontinuous crack closure behavior observed after a single tensile overload (OL) under otherwise constant ΔK loading. The investigation was performed on a disk-shaped compact tension DC(T) specimen made of Al6351-T6 with thickness of 2 mm, in order to simulate the case of a crack propagating under plane stress conditions. The Digital Image Correlation (DIC) technique

The presented paper deals with the mechanical properties of Friction Stir Welded (FSW) AA2024-T351-joints. The material’s response to the static and fatigue strength (S–N curve) is summarised from previous work and referenced, while the testing methods and results for the fatigue and fracture mechanics’ parameters regarding to the fatigue crack growth and occurrence of final fracture are discussed

Because of its local nature, the influence of residual stresses on fatigue life of welded joints in the high cycle regime can be quantified by the residual notch stress intensity factor (R-NSIF). The standard methodology used for its assessment requires a very fine mesh and this is the reason why 2D numerical models were used first in literature. The calculation of R-NSIF values via 3D models is very

The relative importance of crack closure and residual stresses on fatigue crack growth (FCG), which is controversial, is studied here. FCG is predicted numerically in CT specimens of Ti-6Al-4V alloy submitted to single overloads, assuming that crack tip plastic strain is the driving force. The numerical procedure, which includes the effects of crack tip blunting, material hardening, crack closure and

This paper presents a new cohesive law for modelling interfaces under mixed-mode cyclic loading. The formulation is based on the definition of a free energy function which governs the interface behaviour under monotonic loading, which is then extended to cyclic-driven decohesion through the introduction of a scalar damage variable, whose evolution in time is governed by a phenomenological rate equation

This paper presents the experimental investigations of the effects of thermal aging on the embrittlement failure mechanism and fracture toughness of 16MND5 reactor pressure vessel (RPV) steel using clamped single edge notched tension (SENT) specimens with different sizes. In order to study the embrittlement induced by thermal aging, the 16MND5 steel was subjected to accelerated thermal aging for 1000 h

Fatigue crack growth assessment of 2024-T3 aluminum alloy is carried out on the basis of a recently developed peridynamic fatigue model. The governing remaining-life equation of the peridynamic fatigue model has been solved by two different approaches i.e. numerical and analytical approaches to perform fatigue-crack growth simulations for 2024-T3 aluminum specimen with a pre-existing crack. Remaining-life

The motivation of the present study entails the determination of fracture initiation of a single crystal copper edge-crack specimen subjected to tensile load by considering the influence of crystallographic anisotropy, strain hardening and damage accumulation. To accomplish the purpose of this study, a damage criterion coupled with crystal plasticity finite element method was used to determine material

The stress intensity factors (SIFs) of the kinked crack emanating from a hole in an infinite plate are calculated by Muskhelishvili’s formalism. A numerical Schwarz–Christoffel (S-C) conformal mapping method is proposed to calculate the mapping function which transforms the relatively complex configuration of the crack onto a unit circle. The application of this method to the cases of kinked crack

This paper studies the fracture characteristics of wood in the longitudinal direction by combining KR curves and GR curve for fracture resistance ability analysis. Three-point-bending fracture test is carried out on the notched specimens. Digital image correlation (DIC) technique is applied to obtain the crack opening displacement and then calculate the equivalent crack length according to the double

The thermo-elastic analysis of thermally induced crack in functionally graded materials (FGMs) is performed using extended isogeometric analysis (XIGA). For the study, two types of cracks, i.e., adiabatic and isothermal, are considered in the FGM body. The suitable enrichment functions are employed to capture the discontinuity (i.e., displacements and temperature) along the crack face and singular

Corrosion fatigue is identified as the main failure mechanism for structures working in severe corrosive medium subjected to cyclic rotating bending fatigue, for example crude oil storage tank (COST). Emphasis is placed on the study of corrosion pit formation and the development of cracks from pits. An improved equivalent initial flaw size (I-EIFS) is proposed for corrosion fatigue life prediction

Quasi-static fracture toughness tests were carried out on four types of beam specimens in order to determine the mixed mode I/II initiation fracture toughness of a secondary bonded laminate composed of uni-directional pultrusion composite plies. The tests included the double cantilever beam (DCB) test for pure mode I; the mixed mode end loaded split (MMELS) test for a mode I dominant mixed mode I/II

Ore beneficiation processes produce huge quantities of waste rock in the form of tailings. For dispersed remote artisanal mining sites that are unapproachable to strong construction and building materials, compacted MTs can be utilized an alternative to construct civilian buildings. The mechanical behaviors of compacted clay and adobe masonry were studied by numerous researchers; however, the understanding

The results of theoretical and experimental studies of brittle and quasi-brittle fracture of plaster plates containing a circular hole and subjected to non-uniformly distributed compression are presented. This paper summarizes the results, partially published by the author earlier. To predict the critical load at the instant of crack initiation in case of quasi-brittle fracture with a developed process

We consider crack tip deformations under plane stress conditions of a Neo-Hookean sheet reinforced by Neo-Hookean fibers, whose orientation and elastic properties are described by discrete and continuous spatial distributions. The mechanical behavior of the composite is described in terms of the first and fourth invariant of the right Cauchy-Green tensor following [1,2,3]. The crack tip integrals developed

Thermal fracturing is a common phenomenon occurring during significant cooling or heating in diverse engineering problems and natural processes. Multiple thermal fractures caused by cooling may initiate, propagate, arrest, and reactivate under thermal stresses and inter-fracture stress interactions, leading to typical hierarchical fracture patterns. The reactivation, further propagation, and permanent

Delamination has been introduced as the most crucial failure mechanism in laminated composites due to the absence of reinforcement along the thickness. It is necessary to investigate the phenomenon of delamination by researchers carefully to take full advantage of the composites' valuable properties. The purpose of this study is to quantify the effects of energy dissipation mechanisms on the interlaminar

To simulate the real distribution of pressure on the specimen in the Brazilian test, non-uniform distribution is assumed to be the form of pressure distribution on the disk. The analytic solutions of the stress field for an uncracked Brazilian disk under several typical non-uniformly distributed pressures are obtained by the power series expansion method and mathematical method. Then the analytic solutions

In this study, complex variable theory was employed to study the stress distribution for rock mass containing a hole with complex shapes. The method of mapping function calculation using optimization technique was investigated and improved. The shape-related mapping function was defined for parameter analysis. A new objective function for mapping function determination was developed to calculate related

This paper aims to develop a three-dimensional isogeometric-reproducing kernel particle method (IGA-RKPM) coupling approach to study the buckling behavior of cracked isotropic and orthotropic plate and shell structures. The IGA and RKPM-based meshfree methods are coupled successfully through a reproducing condition in the physical domain that guarantees the higher-order polynomial continuity of basis

It is vitally important to measure the brittle crack arrest properties of shipbuilding steels to ensure that accidental damage will not result in total structural failure. Wide-plate test methods allow for direct measurement of the crack arrest toughness but this kind of testing is incredibly expensive. Therefore, there is a need for cheaper and simpler test methods which are able to measure a material’s

Three-dimensional location and characterization of microcracks in controlled fracture tests of hard coal beams were experimentally conducted through the quantitative acoustic emission (AE) technique. The recorded AE events were physically interpreted as displacement discontinuities (DD), i.e. microcracks, involving only opening/closing and shear-sliding mechanisms to describe the fracture modes directly

In this work, based on the traction-separation (T-S) constitutive relations extracted from molecular dynamics (MD) simulation, a peridynamics (PD) model is proposed to investigate the crack propagation behavior of the polycrystal BBC-Fe under mode I loading condition. MD simulation is carried out to give an insight into the cracking process and fracture mechanism according to the analysis of atomic

The main objective of this study is to determine the image forces during the interaction between the dislocation and a semi-infinite crack in a bi-material. Our problem is formulated by using two materials bonded together with an adhesive cracked at the end and loaded by an uniformly distributed load according to the first mode of fracture (Mode I). The analysis of the image forces is mainly based

The present study aims at charactering the crack growth resistance parameter in an 1 mm thick interstitial-free (IF) steel sheet using the energy dissipation rate parameter, R. The R-Δa plots of single-edge and double-edge notched tension specimens have been determined with only additional computations of mechanical and optical test data already generated in the course of determining the variation

As a high power transmission capacity and long durability constitute an essential requirement for mechanical machinery, the mechanical transmission gears need to be modified to improve the performance. The increasing drive side pressure angle is one of the methods for enhancing load-carrying capacity of the spur gear. The fracture characteristics of asymmetric gears need to be investigated to estimate

The single-edge V-notched beam (SEVNB) method based on the laser notching approach can effectively overcome the shortcoming of time-consuming and avoid large errors in traditional fracture toughness measurement ways, yet there is still a lack of systematic research on the normativity of V-notches as well as the applicability of ceramics with various compositions and microstructures. Taking oxide (ZrO2

Effect of similar and dissimilar interface layers on delamination in hybrid plain woven glass/carbon epoxy laminated composite double cantilever beam under Mode-I loading has been investigated experimentally and analytically. Glass-glass, glass-carbon interface layers in three different configurations of hybrid plain woven glass/carbon epoxy laminated composites were fabricated. Valvo’s mode partition

The tunnels excavated in a mountain body interact with the jointed rock mass under compression-shear and present a complex stress state. The joints often have a significant influence on the possible damage points of tunnels. However, the failure behaviour of jointed rock mass with a hole under the compression-shear condition is still unclear. The crack coalescence mechanism needs to be further explored

Users of the most popular procedures for determining the linear elastic fracture mechanics parameters on polymers have noted that the repeatability and reproducibility of the results depend strongly on the quality of the notches generated. In an attempt to provide a better understanding, polysulfone specimens were pre-cracked using classical razor blade methods (tapping and sliding), and also by the

In this work, a comprehensive experimental investigation was carried out to characterise the quasi-static tensile and compressive behaviour of notched and plain specimens made of 40% wt. glass fibre-Polyphenylenesulphide (40GF-PPS) short fibre reinforced composite. To this end, plain and notched specimens (with notch radius ranging from 0.25 mm to 10 mm) were manufactured with two different fibre orientation

The adhesive joints used in airframe and wing sections of aircrafts are generally subject to dynamic (fatigue) loading rather than static loading due to environmental conditions. The dynamic loading formed on wing sections of aircraft is generally in the form of fully reversed fatigue. This study experimentally and numerically investigated the lifetimes of single-lap joints (SLJs) of five different

To further investigate the macroscopic failure law of fractured rock mass, we have performed investigations on the initiation mechanism of microcracks in fractured rock mass from the perspective of micromechanics. The failure of fractured rock mass is essentially due to the accumulation of energy between rock particles to a certain extent, which triggers a series of micro-failure events. In this paper

This study presents a peridynamic model with an improved energy-based surface correction to simulate fractures of random porous materials. There exists a surface effect due to incomplete neighborhoods of boundary or near-boundary points in peridynamics. A surface correction approach is proposed to correct the surface effect on or near the boundaries, including outer boundaries of the materials and

The fracture behaviour of layered rocks is strongly influenced by bedding planes, which usually have lower strength than rock matrix. In this study, experimental and numerical fracture toughness tests were conducted on cracked straight through Brazilian disc (CSTBD) specimens with a prefabricated crack to study the bedding plane properties on the fracture behaviour. Experimental studies were mainly

More than forty years ago, several researchers suggested a hypothesis that the front of a fatigue crack must intersect the free surfaces at a certain (critical) angle to ensure the finite energy flux at the terminal (vertex) point(s). Since its formulation, this hypothesis was under scrutiny in many studies, which utilised various materials, cyclic loading conditions and different specimen geometries

In this paper, we present two non-local mechanics models of recycled coarse aggregate (RCA) concrete based on peridynamics modeling and simulation, i.e. RCA model 1 and RCA model 2. The recycled coarse aggregate concrete is a heterogeneous composite that has five different phases including natural coarse aggregate, old interfacial transition zone (ITZ), old cement mortar, new ITZ, and new cement mortar

Fissures are generally existing in engineering rock mass, and cracking pattern observed in specimens with multiple fissures is analogous to the pattern obtained in specimens with two fissures, whereas the cracking coalescence of real rock specimen under triaxial compression have rarely been investigated. Therefore, thirty fissured rectangular specimens containing two non-coplanar fissures with different

In this research, the extended finite element method (XFEM) in conjunction with the combined approximation (CA) is utilized for estimating the fatigue life of two-dimensional isotropic bodies under variable-amplitude loading. In the proposed method, called CA-XFEM, in addition to the fact that no re-meshing process is required, the crack growth path is determined without the need to solve the whole

The ductile crack initiation observed in structural steels subjected to ultra-low cycle fatigue (ULCF) loading often leads to the catastrophic failure in steel structures. In the existing ULCF damage models, there is always a contradiction between the cost of model parameters calibration and prediction accuracy. In order to solve the contradiction, a one-parameter model for ULCF damage evaluation of

Laboratory-scale experiments on mixed-mode I/II (including pure modes I and II) fracture of non-oriented columnar saline ice were performed. In the experiments, obliquely notched, three-point bending specimens were used, with the load applied in the direction perpendicular to the columnar grains. Tests were performed on dry isothermal (−10 °C) specimens and specimens floating in water and having a

In this paper, the coherent gradient sensing (CGS) method is extended to study the local stress fields and fracture behavior of a blunt V-notch tip. First, the optical governing equations of the CGS method are derived based on Filippi’s stress equation for blunt V-notches and the concept of the notch stress intensity factor (NSIF). Moreover, the CGS fringe patterns in the vicinity of the blunt V-notch

Self-restraint caused by differential shrinkage along the radius of a concrete ring has great driving effect on the restrained cracking in the traditional ring test. In order to estimate cracking potential of concrete under restrained shrinkage, i.e. steel ring restraint effect, an improved circular/elliptical ring test was proposed by pre-setting a 6 mm long real crack at the inner circumference of

Since the fracture toughness of materials in the ductile and brittle transition region presents obvious scatter, Weibull stress based on the local approach to fracture is widely used to clarify the randomness. A large number of detailed finite element analyses are necessary to be carried out for the calculation of Weibull stress, especially for the complex structures and loads. In order to simplify

This paper presents the reinforcement impact of a functionally graded (FG) coating layer on the induced stress distribution of circular cross-section bars weakened by multiple cracks and cavities under torsional moment. The entire cross-section of the bar is under torsional loading governed by Saint-Venant’s principle. The shear modulus of the FG coating layer is assumed to vary exponentially in the

The evaluation of the stress intensity factors (SIFs), T-stress, and higher-order coefficients in the crack tip asymptotic field in the extended finite element method (XFEM) is investigated based on the over-deterministic displacement field fitting method. Numerical examples of central cracked and edge cracked plate under uniaxial tension exhibit the accuracy of the evaluated coefficients. A convergence

The peridynamic theory of solid mechanics is applied to the continuum modeling of the impact of small, high-velocity silica spheres on multilayer graphene targets. The model treats the laminate as a brittle elastic membrane. The material model includes separate failure criteria for the initial rupture of the membrane and for propagating cracks. Material variability is incorporated by assigning random

In the current paper, effects of alkaline solution to binder ratio (Al/Bi) (i.e. 0.65, 0.75 and 0.85) on fracture parameters of steel fiber reinforced heavyweight geopolymer concrete (SFRHWGC) with different fiber volume fractions (Vf) (i.e. 0.5%, 1% and 1.5%) are investigated using work of fracture method (WFM) and size effect method (SEM). Moreover, relationship between each of the fracture parameters