Most fracture mechanics analysis is based on the assumptions of prefabricated crack and ideal undamaged body. In practical, a cracked structure contains microstructural defects so that the material damage is considered to exist in the body rather than an ideal defect-free body. In this paper, it is the first time to take the material damage into account to the constitutive equation of quasicrystals

Peridynamic models typically adopt regular point distributions and uniform horizons, limiting their flexibility and engineering applicability. In this work, a micropolar peridynamics approach with a non-uniform horizon (NHPD) is proposed. This approach is implemented in a conventional finite element framework using element-based discretization. Through modification of the dual-horizon approach in the

The main objective of this manuscript is to evaluate the capability of the fracture criteria and numerical methods to predict fracture properties of the specimens fabricated using the Fused Deposition Modelling (FDM) 3D-Printing method. Five different thermoplastic materials are 3D printed in Semi-Circular Bending (SCB) specimens configuration and subjected to three-point bending loading to record

In this investigation synergistic assessments of fracture toughness and activation volume for plastic deformation of two typical body centered crystalline (bcc) and face centered crystalline (fcc) high entropy alloys containing Al, Cr, Co, Cu, Fe and Ni have been made by standard practices; these experiments together with the assessment of conventional mechanical properties were carried out to understand

In rock engineering, the failure mechanism of a fractured rock mass under compression-shear stress has been focused on, but the effect of filler in fracture-filled rock masses has not received widespread attention. In this research, compression-shear tests are performed on rock-like specimens with three fissures under four filling conditions, unfilled, gypsum filled, cement filled and resin filled

This paper makes the first attempt to apply the generalized finite difference method (GFDM), a recently developed meshless collocation method, for fracture mechanics analysis of dissimilar elastic materials with interfacial cracks. The main idea of the GFDM is to divide the entire computational domain into a set of overlapping small subdomains in which the local Taylor series expansion and moving-least

Experimental and theoretical analyses are presented that assess true mode II fracture toughness, KIIc, fracture energy, GIIc, and associated fracture process zone (FPZ) in anisotropic rocks. The term true signifies the type of mode II crack that grows in a self-planar manner as a result of shear stresses, and thus differentiates it from a generic mode II crack that often extends by forming a tensile-induced

The work presented in this paper provides guidance in optimally determining the appropriate fitting region used in digital image correlation (DIC) when fitting a crack tip field model to DIC data. In this work, the technique is applied to the CJP crack tip field model and uses the Levenberg-Marguardt (L-M) iterative method to solve for the crack tip position. This is combined with an error analysis

Thermal barrier materials used in gas-turbine engines and aerospace vehicles have to resist large thermal gradients or high heat fluxes. The existence of high temperature gradient results in nonlocal effect of heat conduction, especially in very small time and space scale, the size effect of heat conduction is significant. In this work, a nonlocal dual-phase-lag heat conduction model is adopted to

Accurately obtaining the material parameters of the damage model is very important for the ductile fracture simulation of steel structures made of high strength steel (HSS). The combination of micromechanics with the uncoupled phenomenological fracture model can be used to obtain the material parameters of ductile fracture locus only from the uniaxial engineering stress-strain relationship. A micro

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

This paper presents a robust meshfree technique for computation of moment and stress intensity factors, and analysis of fatigue crack growth in cracked plates under the application of in- and out of-plane loads; a methodology for efficient and accurate computation of parameters of fracture mechanics problems is thus developed. Although having small computational labor and few complications of formulation

An improved semi-circular bend (SCB) specimen is introduced to obtain the mixed mode fracture envelope of a ductile adhesive with a considerable fracture process zone ahead of the crack tip. This specimen has been used for brittle adhesives fracture energy measurement. The proposed test procedure is very simple to implement and does not require any special loading fixture. The specimen is able to cover

The present study employs a continuum mechanics approach called peridynamics to investigate the deformation as well as the damage behaviour of a 2D microstructure obtained from a plasma sprayed ceramic coating used in solid oxide fuel cell (SOFC) sealing systems. Due to the production process, plasma sprayed ceramic materials possess typical microstructural features, such as globular pores, interlamellar

Failure characteristics of flawed rocks subjected to true triaxial stress are not studied, and the cracking mechanism is not fully understood. Especially, the damage and failure mechanisms incorporating the effect of material properties such as grain diameter are seldom revealed. In this study, true triaxial compression tests are conducted on flaws-contained specimens of coarse and fine sandstone,

This study aimed to investigate the fracture behavior of a cracked orthotropic FGM medium when exposed to an in-plane harmonic load. The mechanical feature of the medium exponentially varied along the y-axis. Using the Fourier transform method, stress was analyzed by assessing Volterra edge dislocation in orthotropic FGM media. The obtained solution was then applied to derive Cauchy singular integral

This paper proposes an axisymmetric ordinary state-based peridynamic model considering the thermal expansion effect for temperature-induced cracking of linear elastic solids. Both the force state and bond failure criterion of the model are built in axisymmetric domain. The direct calculation for peridynamic bond energy density of the axisymmetric model considering thermal terms is given. The adaptive

This work presents a generalized bond-based peridynamic model named bond-based correspondence model to simulate the fracture. This model combines the advantages of bond-based peridynamics and the correspondence model (non-ordinary state-based peridynamics). The peridynamic pair-wise force is calculated by classical constitutive equations through the relation between peridynamic pair-wise force and

In laminated, anisotropic unconventional rocks (ultra-tight shale, tight gas, coal seam, and so forth), the true hydraulic-fracturing mode is a complex, mixed-mode process. The fracture-modeling practitioner often encounters a wide range of fracture models. The selection of an appropriate fracture model has become a daunting task with significant implications for the hydraulic-fracturing pre-treatment

As three-dimensional (3D) atomistic simulations require much higher computational costs, two-dimensional (2D) atomistic simulations under plane strain condition are widely used to study dislocation emission from the crack tip. In order to study the difference of crack tip behavior in 2D and 3D simulations, both 2D and 3D atomistic simulations of the anisotropic crack tip response in hcp titanium were

We investigate the use of combining SIMP topology optimization and phase field method to fracture for maximizing the fracture resistance of a structure composed of two materials. The optimization problem is formulated with respect to maximizing the external work under the constraint of inclusion volume fraction. The performance and convergence of the proposed algorithm are investigated. It is shown

This work addresses an experimental investigation of the cleavage fracture behavior for ASTM A572 Grade 50 steel welds fabricated by different welding processes. A primary purpose of this study is to examine a correlation approach to evaluate fracture toughness values of steel welds based on Charpy V-notch (CVN) impact energy data thereby enlarging existing relationships between fracture toughness

Crack onset in PMMA holed plates subjected to tensile stresses is studied experimentally and by the coupled stress and energy criterion of the Finite Fracture Mechanics (CCFFM). The elastic, strength and fracture properties of PMMA are determined by the standard tests, a clearly nonlinear stress-strain relation being identified in the tensile tests. Thus, a novel numerical implementation of the CCFFM

When a rock mass has undergone a long period of geological structural change, various defects such as pores and cracks. Here, the effects of defects on the mechanical properties of a rock mass were investigated. In this research, the strength, deformation and crack evolution behavior of marble containing double elliptic holes under uniaxial compression were evaluated by experiment and numerical simulation

In this paper, an asymptotic solution is obtained for mode I stress and solvent concentration fields around stationary planar sharp V-notches in polymer gels at equilibrium state via poroelasticity theory. To this end, the mechanical equilibrium equations are first solved by employing a proper Airy stress function and then the solvent concentration field is obtained accordingly. It is shown that the

To investigate the effects of the pre-existing single crack angle on the mechanical behaviors and energy storage characteristics of red sandstone, a series of uniaxial compression and single-cyclic loading–unloading uniaxial compression tests were conducted on red sandstone specimens with five crack angles. The relationships among the crack angle and the mechanical properties, failure modes, and energy

To consider a mechanistic explanation of the mean stress based line method (called LM) for estimating the notch fatigue limit, the limit values predicted by the LM are investigated from both the energy condition required to create fractured surfaces and the crack propagation condition of the linear elastic fracture mechanism. Based on the energy condition, an energy release criterion (ERC), was introduced

Fracture properties of asphalt mixtures containing fine and coarse Electric-Arc Furnace (EAF) aggregates were determined at low-temperature conditions by implementing Cohesive Zone Modeling (CZM). Semi-Circular Bending (SCB) test was conducted in both fracture Mode I and II (opening tensile and in-plane shear, respectively), and the bi-linear traction separation law was used to obtain the coefficients

Mechanisms of ductile failure in brittle matrix composites with metal reinforcements are investigated using a mechanistic approach to incorporate material anisotropy. Rapid void expansion with increasing remote strain and at nearly constant remote strain (cavitation) is modeled. Fracture energy, total energy absorbed, and cavitation limit is obtained as a function of material anisotropy. It is observed

A wedge split test in mode I and mixed-mode was designed and performed for wood at structural component scale. The displacement fields around cracks during propagation were recorded and analysed to provide information on crack tip position, the composition of deformation modes, resistance to fracture propagation, and separation of the crack lips. The data were fed into a non-linear numerical finite

Sharp notches occur in constructions and lead to stress concentrations. Thus they are dangerous points of constructions and must be properly evaluated. In the present study the effect of a free surface on crack initiation conditions is observed and evaluated by means of a 3D model of a specimen with a sharp notch and by means of the finite fracture mechanics of general singular stress concentrators

Additive manufacturing (AM) has enabled the fabrication of complex geometries directly from the design data and gained a lot of interest. However, AM products can contain pores, which can significantly reduce fatigue life. The main focus of this work is to evaluate the effect of the pores in Ti6Al4V dog-bone samples, produced by AM, and propose a methodology to estimate the fatigue life reduction due

Sandwich structures are widely used for the design and fabrication of lightweight structural systems, due to their capability to exhibit excellent structural and thermal performances at low material usage. Understanding the phenomena of propagation of macro-cracks in the core and delamination at the face-to-core interface are aspects of great computational interest. Linking sophisticated models with

The mixed mode I-II crack propagation process in concrete subjected to quasi-static conditions has been extensively investigated. However, in engineering practice, many concrete structures are subjected to various loading rates. The rupture process is closely related to the loading rate. Therefore, the knowledge of loading rate effect on the mixed mode I-II crack propagation process in concrete is

Hydrogen is foreseen as a promising energy carrier that can control global warming by reducing CO2 emissions. However, hydrogen is associated with an embrittlement phenomenon that imparts substantial damage to the infrastructure by reducing the ductility, fracture strength, strength bearing capacity, etc., of metallic components. Therefore, understanding hydrogen-induced crack initiation mechanisms

The mode I critical stress intensity factor of a Scots pine beam was studied in the tangential-radial crack propagation system. The beam was naturally dried in the lab enviroment following a year and a half-long exposure to the harsh climate of Trondheim in Norway. A comparison between critical stress intensity factor values obtained by means of experimental and theoretical approaches were made. Finite

We present a novel stochastic extended finite element (S-XFEM) method for solving fracture mechanics problems under uncertainty. The proposed S-XFEM couples XFEM and a novel multi-output Gaussian process based machine learning algorithm, referred to as the hybrid polynomial correlated function expansion (H-PCFE). With this approach, the underlying stochastic fracture mechanics problem is decoupled

The effect of environmental conditions on the fracture behaviour of two types of adhesively bonded joints (wet-aged and non-aged) is experimentally studied under mode II loading. End Loaded Split tests were performed at various temperatures (−55 °C, room temperature (RT) and 80 °C) on non-aged and aged specimens. The non-aged specimens were stored in a laboratory under controlled conditions at RT (23

Microporosity is one of the most common defects in nickel base single crystal (N-SC) superalloys, which is a great threat to fatigue performance. In this paper, nine porosity-related fatigue damage parameters for N-SC superalloys were selected by referring to those parameters originally proposed for casting and 3D printing metal materials as well as the critical plane damage parameters commonly used

Artificial intelligence is playing an increasing role in materials testing, whether it is in a new material design, designing new testing methods, or creating a model to predict materials properties. In this research, the artificial intelligence was from an artificial neural network (ANN) and an adaptive neuro-fuzzy inference system (ANFIS), which was applied to predict mixed mode I/II fracture toughness

Tunnel excavation changes the original stress state which directly leads to the surrounding rock fracture, many researches focus on the stress or displacement evaluation surrounding an opening or a tunnel. Flaws and openings dramatically change the state of internal stress within the rock mass, and the internal stress concentrates at some certain positions surrounding the opening. When the flaws and

This paper proposes a notch fatigue life prediction model to account for the effect of geometry and applied stress. A double-slope method was proposed to calculate the critical distance, which was utilized to determine the damage zone of geometrically complex structures. An elastic geometrical feature factor was defined to characterize the stress concentration. Considering the effect of applied stress

A non-linear relation between fracture strain and temperature is observed in Split Hopkinson Tension Bar (SHTB) tests for free-cutting steel 50SiB8 at high strains and high temperatures, due to blue-brittleness. A fourth-degree polynomial function for the thermal parts of the original and modified Johnson-Cook (JC) fracture strain constitutive equation is suggested and the corresponding parameters

This paper investigates the mechanical and fracture properties of basalt fiber reinforced fly ash geopolymer concrete with different length (3 mm, 6 mm, 12 mm and 18 mm), which were tested by means of compressive strength test, splitting tensile strength test and three point bending test. The fiber reinforced mechanism was characterized by SEM. Simultaneously, the strain field and displacement field

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

Drilling and blasting method is a common method of rock fragmentation in engineering. Meanwhile, the dynamic behaviours of rocks under blasting loads are different from those under impact loads. In this paper, a large-size arc-edge rectangle with edge notches (LAREN) specimen was posed to investigate the dynamic fracture parameters of brittle rock materials under blasting load. Three types of radial

This paper explores and analyses how reinforced concrete beams, can be restored and repaired after sustaining damage from monotonic loading. Epoxy resin was used to repair the beams. By employing a technique known as the “acoustic emission (AE)” technique, the damage sustained by the beams under monotonic loading can be evaluated. The reference beam (S1C), and the repaired beam (S4B), were both prepared

We propose a fully coupled model for damage in brittle solids undergoing thermomechanical deformation. The model is fully coupled in the sense that, just as the thermal field appears in the evolutions of mechanical deformation and damage, the deformation and damage fields also occur in the evolutions of the other two complementing state variables. Damage is presently described by a continuous field

A simple method for determining the material constants of rock (e.g., fracture toughness KIC and tensile strength ft) using normal distribution with respect to average grain size gav is proposed as an alternative to the commonly used of curve fitting using rock test data. Supposing different characteristic crack a∞∗ and considering different fictitious crack growth length Δafic at peak load Pmax for

Double cantilever beam (DCB) specimens were prepared according to standard surface mount technology (SMT). The samples were stored inside an environmental chamber at two different relative humidity values (i.e. 40 or 100%) for either 2 or 4 h. Then they were aged at 25 °C, 75 °C or 125℃ for the same time. Finally, after being cooled to room temperature, fracture tests were performed under mode-I loading

This study presents a novel ordinary state-based peridynamic model for geometrically nonlinear analysis of plates. The nonlinear strain energy density and nonlinear equations of motion for a plate in peridynamics are obtained based on the principle of virtual displacements by using Total Lagrange formulation. The numerical procedure for geometrically nonlinear analysis of a plate is also provided.

This study presents a novel physics-guided machine learning model for two-dimensional structures based on ordinary state-based peridynamics. The linear relationships between the displacements of a material point and the displacements of its neighbours and the applied forces are obtained for the machine learning model by using linear regression. The numerical procedure for coupling the ordinary state-based

The diverse joint distributions in natural layered rock masses bring a great difficulty to the study on fracturing characteristics of surrounding rock in the process of tunnel excavation. The joint angle plays a vital role in the fracturing behaviors of tunnels. In this paper, taking the shallow-buried tunnel in layered rock masses as the background, a series of uniaxial compression tests were performed

The fracture properties (e.g. tensile strength, fracture toughness) are regarded as the material constants, which could be used to predict the fracture behavior of concrete. However, the scattered distribution and size effect of test results make the prediction in conventional methods difficult. In this study, the artificial intelligence (AI) approaches and the Boundary Effect Model (BEM) closed-form

Some cyclically loaded components such as mooring chains can develop fatigue cracks in locations where the shape of the part is equivalent to that of a curved or bent round bar. Here we consider a semi-elliptical crack growing from the surface of a curved round bar. This geometry can for example represent a chain link segment with a crack located at its inner- or outer radius. The surface crack can

This paper investigates the fatigue property of U rib-crossbeam-deck connections in orthotropic steel bridge decks (OBD) under combined loading of bending and torsion by using the improved traction structural stress method. Applicability of the method for analyzing OBD under combined loads is validated by comparing the simulation results with the experimental results from the literature. The fatigue

Hydrogen assisted fracture near welds is the result of a combination of microstructural changes and the accumulation of hydrogen. With the aim of predicting local hydrogen concentrations, hydrogen redistribution near a crack tip is simulated using a Boundary Layer approach and diffusion modelling is modified by trapping phenomena. The simulated non-homogeneous geometry includes layers that reproduce