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Fracture analysis of functionally graded material by hybrid meshless displacement discontinuity method Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-25 H. Zheng; J. Sladek; V. Sladek; P.H. Wen
The recent progress in the development and research of functionally graded materials (FGMs) has prompted the development of numerical methods in engineering analysis for continuously non-homogeneous media. This paper presents the hybrid Meshless Displacement Discontinuity Method (MDDM) for a cracked structure with functionally graded materials. The fundamental solutions of displacement discontinuity
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The influence of liquid nitrogen cooling on fracture toughness of granite rocks at elevated temperatures: an experimental study Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-25 Zuliang Shao; Xuhai Tang; Xiaoguang Wang
In order to investigate the fracture toughness of granite samples after elevated temperature treatment and liquid nitrogen (LN2) cooling, a series of fracturing tests were performed on semi-circular bend (SCB) specimens containing pure mode-I fracture. The acoustic emission (AE) technique was employed to monitor the damage process during the test. The experimental results indicate that, overall, the
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A study of crack initiation and source mechanism in the Brazilian test based on moment tensor Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-25 Wei Sun; Shunchuan Wu
It has been widely accepted that the Brazilian test can be used to obtain the indirect tensile strength of geo-materials. However, the effects of the contact conditions and the heterogeneity of the rock affect the micro-failure of the disc and the accuracy and feasibility of the Brazilian tensile strength (BTS), which typically leads to deviations from the results of the direct test. This study uses
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Elastic-plastic solutions for corner and surface cracks emanating from stress concentrators Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-25 Wei Guo; Wanlin Guo
Three-dimensional (3D) constraint effects for part-through cracks, such as corner and surface cracks, emanating from stress concentrators play important role in damage tolerance design of structures, but have hardly been investigated in the frame of 3D elastic-plastic fracture theory. Here the ability of current elastic-plastic solutions to describe 3D constraints and their effects on crack tip fields
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Three-dimensional numerical investigation of the interaction between multiple hydraulic fractures in horizontal wells Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-21 Kaikai Zhao; Doug Stead; Hongpu Kang; Fuqiang Gao; Davide Donati
Complex, non-planar fracture geometry is often observed in multi-stage hydraulic fracturing. The opening of hydraulic fractures results in a disturbance of local stress, which in turn affects the propagation of the adjacent fractures (stress shadow effect). The interaction between multiple fractures is of major importance in the design of fracturing treatments. In this study, a fully-coupled three-dimensional
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Observing progressive damage in carbon fiber epoxy laminate composites via 3D in-situ X-ray tomography Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-24 Alejandra M. Ortiz-Morales; Imad Hanhan; Jose Javier Solano; Michael D. Sangid
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Study of mixed mode I/II cohesive zone models of different rank coals Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-24 Jianfeng Yang; Haojie Lian; Vinh Phu Nugyen
The present work studies the Park–Paulino–Roesler (PPR) model, a unified potential-based cohesive zone model (CZM), for mixed mode I/II fractures in different ranked coals, including weakly caking coals, fat coals and anthracite, by using disk-shaped compact tension (DC(T)) tests and punch-through shear (PTS) tests. The PTS experiments showed that with the increase in coal rank, the initial shear stiffness
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High temperature translaminar fracture of woven-ply thermoplastic laminates in tension and in compression Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-24 Juan Daniel Pujols Gonzalez; Benoit Vieille; Christophe Bouvet
The translaminar fracture behavior of three composite laminates, based on thermoplastic matrix PEEK reinforced by a woven carbon fibers obtained by consolidation process, has been studied by means of Compact Tension (CT) and Compact Compression (CC) tests. An orthotropic laminate and two quasi-isotropic laminates, have been tested at room temperature (RT) and at 150°C (i.e. for a temperature slightly
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A modified peridynamic method to model the fracture behaviour of nanocomposites Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-24 Dayou Ma; Patricia Verleysen; Sarath Chandran; Marco Giglio; Andrea Manes
In the present work, a numerical investigation based on a modified peridynamic method of fracture properties of epoxy resin reinforced by nanoparticles, more specifically hyperbranched polyester (HBP), was conducted. Due to the specific features of HBP, certain material nodes in the numerical model were constrained to accurately replicate the effect of HBP in pure epoxy resin, and a Monte Carlo method
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Cohesive fracture model of rocks based on multi-scale model and Lennard-Jones potential Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-24 Qindong Lin; Shihai Li; Chun Feng; Xinquan Wang
With the aim of modelling the energy dissipation phenomenon during the initiation and propagation of cracks, a novel cohesive fracture model is proposed in this study based on the multi-scale model of rocks and the Lennard-Jones potential between non-bonding molecules. The proposed model establishes the corresponding relationship of deformation in the multi-scale model of rocks and suggests that the
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The response of hybrid titanium carbon laminates to the low-velocity impact Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-16 P. Jakubczak; J. Bieniaś
Impact resistance is one of the more critical and important features of composite materials used in the aerospace industry. The objective of work was to evaluate the hybrid titanium carbon laminate resistance to dynamic loads. The paper utilizes numerous criteria for evaluation of impact behaviour of materials, including force change, energy absorption characteristics and failure identification. To
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Effect of lamellar microstructure on fatigue crack initiation and propagation in AlCoCrFeNi2.1 eutectic high-entropy alloy Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-20 Wei Chen; Yuting Wang; Luling Wang; Jianqiu Zhou
A theoretical model is established to describe the crack initiation and propagation in AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA). By the Gibbs free energy change, the critical cycle number for crack initiation has been calculated which indicates B2 precipitates in FCC lamellae can delay crack initiation. The dislocation motion from crack tip has been analyzed. The results show that the equilibrium
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Deep learning-based planar crack damage evaluation using convolutional neural networks Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-16 X.Y. Long; S.K. Zhao; C. Jiang; W.P. Li; C.H. Liu
This article presents a novel deep learning-based damage evaluation approach by using speckled images. A deep convolutional neural network (DCNN) for predicting the stress intensity factor (SIF) at the crack tip is designed. Based on the proposed DCNN, the SIF can be automatically predicted through computational vision. The data bank consisting of a reference speckled image and lots of deformed speckled
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Implementation of a J-integral Based Maximum Circumferential Tensile Stress Theory in DDA for Simulating Crack Propagation Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-21 Cungen Wang; Shuhong Wang; Guangqi Chen; Pengcheng Yu; Xinyan Peng
Crack propagation is a very important research subject within the field of rock mechanics. In this study, a J-integral based Maximum Circumferential Tensile Stress theory was applied to the conventional Discontinuous Deformation Analysis (DDA) Method for simulating crack propagation. First, according to the relevant theories of fracture mechanics, a crack propagation theory suitable for DDA was derived
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Mechanical characterization of self-compacting steel fiber reinforced concrete using digital image correlation Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-21 Valeria Quiceno Pérez; David Sebastián Cotes Prieto; Luis Eduardo Zapata Orduz
This paper evaluates the mechanical properties, modulus of elasticity (E) and critical stress intensity factor (KIC), of self–compacting concrete with the addition of hook-ended steel fibers, implementing Digital Image Correlation (DIC) to obtain the horizontal and vertical displacement fields for beams under four-point bending test. Based on the vertical displacements and the crack mouth opening displacement
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Mixed-mode crack growth simulation in aviation engine compressor disk Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-21 V. Shlyannikov; R. Yarullin; M. Yakovlev; R. Citarella; V. Giannella
This study focuses on a mixed mode crack growth analysis of an aviation gas turbine engine (GTE) compressor disk based on simulation principles. The operation damages occur via inclined surface cracks in a “dovetail type” disk-and-blade attachment. Based on the sizes and configuration of this attachment, three geometries for simulation models of the GTE compressor disk are proposed. The biaxial loading
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Experimental and numerical study on the fracture characteristics of concrete under uniaxial compression Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-15 Dihao Ai; Zhen Qiao; Yankun Wu; Yuechao Zhao; Chengwu Li
Since concrete infrastructure may lose its expected physical and functional properties over time, accurate inspection and assessment of such infrastructure systems is necessary to ensure safety and serviceability and prevent unsafe working conditions and the occurrence of hazards. In this paper, an experimental investigation was conducted on several concrete specimens under uniaxial compression to
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A new inverse analysis approach for predicting the fracture mode I parameters of fibre reinforced concrete Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-16 Luís M.P. Matos; Joaquim A.O. Barros; António Ventura-Gouveia; Rui A.B. Calçada
This paper describes the development of a new inverse analysis approach to derive the fracture mode I parameters of fibre reinforced concrete (FRC) by using the experimental data obtained from three-point notched beam bending tests (3PNBBT) and round panel tests supported on three points (RPT-3PS). The approach is based on a global fitting strategy, in which the numerical response is simulated by means
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Determination of Complex Stress Intensity Factors for Interface Cracks in Bi-Material Specimens Subjected to Ununiform Stresses Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-20 Xin Wang; Kuiying Chen
This paper presents the calculation of complex stress intensity factors (K) for interface cracks in commonly used bi-material specimens subjected to arbitrary ununiform stress fields. First, detailed finite element analyses were carried out for cracks in centre-cracked plate (CCP) and single edge-cracked plate (SECP) bi-material specimens of different material combinations under non-uniform stress
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A constraint correction method based on use of a single test specimen Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-20 M. Gintalas; R.A. Ainsworth
Commonly, fracture toughness tests on deeply cracked specimens are used to assess defects in large-scale components. The paper presents a method for selection of test specimen type, size and crack length in order to obtain fracture toughness estimates relevant to defects in cracked pipes. The method uses available closed-form T-stress, stress intensity factor and limit load solutions to determine the
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Simulations of crack extensions in arc-shaped tension specimens of uncharged and hydrogen-charged 21-6-9 austenitic stainless steels using cohesive zone modeling with varying cohesive parameters Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-11 Shengjia Wu; Jwo Pan; Paul S. Korinko; Michael J. Morgan
Crack extensions in uncharged and hydrogen-charged side-grooved A(T) specimens of conventionally forged 21-6-9 austenitic stainless steels are simulated using the cohesive zone modeling approach. Two-dimensional plane strain finite element analyses with fixed cohesive parameters are first conducted to fit the experimental load-displacement curves. Similar analyses using varying cohesive parameters
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Peridynamic modeling of engineered cementitious composite with fiber effects Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-12 Zhanqi Cheng; Yuyang Hu; Liusheng Chu; Chengfang Yuan; Hu Feng
The engineered cementitious composite (ECC) cracking process involves discontinuities. To solve this difficulty, a semi-discrete model for ECC based on peridynamics (PD) is established. In this paper, the pairwise force function is modified by using an improved damage coefficient. This model is established by modeling the matrix and the interactions between the fiber and matrix. The interactions between
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An experimental-numerical screening method for assessing environmentally assisted degradation in high strength steels Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-31 Armin E. Halilović; Jonas Faleskog; Magnus Boåsen; Pål Efsing
In this work, an experimental-numerical screening method for studying the elastic–plastic properties in high strength steel subjected to environmentally assisted degradation due to hydrogen is proposed. The experiments were performed on single-edge-notch bend specimens loaded with a monotonic constant displacement rate, and the specimens were electrochemically hydrogen pre-charged and/or in-situ. A
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Numerical investigation of the tensile strength of loess using discrete element method Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-19 Zhilang You; Mingyi Zhang; Fei Liu; Yuwei Ma
The tensile strength of loess is important for the tension-related crack and failure in the Loess regions. While the previous work on the tensile strength of loess mainly focuses on the test method and its variation with different internal and external factors, the micro-mechanical characteristics of the tensile experiments are seldom studied. Taking the unconfined penetrated test (UP test) as example
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Anisotropic thermal-conductivity degradation in the phase-field method accounting for crack directionality Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Lampros Svolos; Hashem M. Mourad; Curt A. Bronkhorst; Haim Waisman
Dynamic loads applied to metals may lead to brittle or ductile fracture depending on the imposed strain rates, material properties, and specimen geometry. With an increase in the applied velocity, brittle to ductile failure mode transition may also be observed. Furthermore, at high strain rates, ductile fracture may be preceded by shear bands, which are narrow bands of intense plastic deformation,
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Efficient parameters identification of a modified GTN model of ductile fracture using machine learning Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-04 Dong Chen; Yazhi Li; Xuan Yang; Wei Jiang; Lingxiao Guan
The ductile fracture behavior of metallic materials is usually coupled with complex stress states. In order to describe the facture behavior of metallic materials under a broad range of stress states, a modified Gurson-Tvergaard-Needleman damage model was proposed by Wei Jiang and has been used to simulate the ductile fracture of 2024-T3 aluminum alloy. However, it was a heavy and trifle job to determine
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Structural health monitoring of adhesive joints under pure mode I loading using the electrical impedance measurement Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-10 Omid Sam-Daliri; Lisa-Marie Faller; Mohammadreza Farahani; Hubert Zangl
The addition of Multi-wall carbon nanotubes (MWCNTs) or functionalized-graphene nanoplatelets (f-GNPs) into the epoxy resin create an electrical conductive networks which can be employed for structural health monitoring (SHM) in sensitive adhesive joints. The opening fracture mode (Mode I) loading condition, as one of the important fracture modes in adhesive joints was precisely evaluated in this study
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Loading rate and temperature effects on the fracture toughness of a high strength bearing steel Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-12 B. Alfredsson; S. Hazar; J. Lai
Fracture of martensitic AISI 52100 steel with 12% retained austenite was experimentally studied at temperatures below the tempering temperature by KIc tests and at extremely low loading rates. Depending on temperature, KIc and JC decreased with 6% to 23% for slow rates. It increased with temperature at standard rate but not for slow loading. FE-simulations with elasto-plasticity, phase transformation
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Modeling of crack propagation with the quasi-static material point method Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-12 Sha Li; Yun Zhang; Jichun Wu; Jun Yu; Xulong Gong
Based on the theory of multiple displacement fields, the quasi-static MPM has been extended to simulate crack behavior in this paper. Compared with the existing crack simulation methods, this new method not only avoids the meshing difficulties and complex shape functions but also supports the modeling of crack growth in an arbitrary direction. The key fracture parameters, stress intensity factors,
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Effects of graphene geometrical characteristics to the interlaminar fracture toughness of CFRP laminates Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-10 C. Kostagiannakopoulou; T.H. Loutas; G. Sotiriadis; V. Kostopoulos
This research paper explores and highlights the effect of aspect ratio (AR) and specific surface area (SSA) of Graphene Nano-Platelets (GNPs) on the interlaminar fracture behavior of carbon fiber-reinforced polymer (CFRP) composites. Various types of GNPs having different aspect ratios were dispersed in an epoxy system by using the three roll milling technique at a fixed content of 0.5 wt.%. The blends
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Coupled continuous–discrete formulation based on microplane and strong discontinuity models for representing non-orthogonal intersecting cracks Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-09 Santosh Kakarla; Giuseppe Rastiello; Benjamin Richard; Cédric Giry
Fracture processes in quasi-brittle materials are governed by the strain localization phenomenon, which involves the formation of localized damage zones and cohesive cracks. In this work, we present numerical tools to model strain localization from the onset of localized damage to the formation and propagation of multiple intersecting cracks. Two main ingredients are used for this purpose: (i) a microplane
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Corrosion fatigue lifetime assessment of high-speed railway axle EA4T steel with artificial scratch Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-09 Yanan Hu; Shengchuan Wu; Philip J. Withers; Huatang Cao; Pei Chen; Yajun Zhang; Zhao Shen; Tomáš Vojtek; Pavel Hutař
The effects of environment (in air and 3.5 wt% NaCl solution) and artificially-induced surface scratches are investigated on the fatigue properties of railway EA4T (also called 25CrMo4) alloy steel. This steel is found to be markedly sensitive to the chloride-containing environment, with cracking at stresses two thirds of the in-air fatigue limit (+/−326 MPa) under rotating bending (Wöhler) tests.
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Finite similitude in fracture mechanics Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-06 Keith Davey; Rooholamin Darvizeh; Jingwen Zhang
Scaled experimentation can potentially provide significant benefits such as reduced costs materials and time in testing but is afflicted by the phenomena of scale effects, where the behaviour at scale can be markedly different to that at full size. The design of scaled experiments is presently predominantly founded on the theory of dimensional analysis, which itself is grounded on the invariance of
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Role of strain rate sensitivity of extrafibrillar matrix on fracture in mineralized collagen fibril arrays Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-10 Bingbing An; Yalin Li
Bone is a biological composite possessing complex hierarchical structure, which endows it with extraordinary damage tolerance. Despite the progress on the relationship between fracture behavior and the hierarchical structure of bone, contributions of the submicroscale constituents to fracture resistance of bone remain elusive. In this study, the calculations are carried out for fracture in staggered
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Analyses of KOP relationship to threshold Kmax,th Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-02 A.K. Vasudevan; D. Kujawski
This article addresses an analysis relating KOP to Kmax,th (FCG threshold) using measured FCG threshold data at various load ratios from R = 0.1 to R = 0.9 under constant amplitude loading. KOP is estimated at near threshold region, due to the low-resolution measurement limit. It is shown that threshold Kmax,th is related to KOP through a critical monotonic plastic strain. Key observation is that this
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Mechanical behavior and acoustic emission characteristics of intact granite undergoing direct shear Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-04 Delei Shang; Yuedu Chen; Zhihong Zhao; Shuantong Shangguan; Xiaofei Qi
Shear behaviors of core samples from a deep geothermal exploration well was investigated using direct shear tests. The fracturing process inside the intact rock samples during shear was monitored using acoustic emission (AE) technique. The results show that three shear stages including compaction, quasi-elastic and failure phases can be easily divided based on the shear stress-shear displacement or
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Analysis of the non-singular stress terms for the sharp notches under anti-plane loading Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-06 Yongyu Yang; Wei Pan; Shanlong Yao; Changzheng Cheng; Qiaoguo Wu
It is the singular term dominating the stress field near the vertex of a sharp notch, while the non-singular terms also play a non-ignorable role on the complete stress field. The non-singular stresses near the apex of anti-plane sharp notches are calculated and their roles on the fracture mechanics are analyzed in this paper. By coupling the singular characteristic analysis with the finite element
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Derivation of a fatigue damage law for an adhesive from in-situ bending tests Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-08 Lassaad Ben Fekih; Olivier Verlinden; Georges Kouroussis
The adhesives used for the attachment of electronic components to space boards should withstand harsh vibrations of the space launch, which requires their characterization in fatigue. The present study investigates Ablestik 8-2 epoxy adhesive within this context. Novel adhesive test assemblies were devised, which consist of a rigid ceramic component bonded to a resonant flexible epoxy-fibreglass (E-glass)
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Mesoscale modelling of size effect on the evolution of fracture process zone in concrete Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-02 Rongxin Zhou; Yong Lu; Li-Ge Wang; Han-Mei Chen
A comprehensive mesoscopic investigation has been conducted to examine the evolution of the fracture process zone (FPZ), using notched plain concrete beams subjected to three-point bending as a generic representation. The concrete beams are modelled as random heterogeneous materials containing three components, namely coarse aggregates, mortar and the interface transition zone (ITZ). To better represent
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Determination of concrete strength and toughness from notched 3PB specimens of same depth but various span-depth ratios Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-10 Xiangyu Han; Yi Chen; Qinghua Xiao; Kai Cui; Qiaofeng Chen; Congming Li; Zemin Qiu
Notched three-point-bending (3PB) tests of small concrete samples with a fixed depth/size but various span/depth ratios can be performed in almost every laboratory. Additional usefulness is added to the flexibility of those fixed-depth 3PB tests in this study by providing a simple closed-form solution for determination of the depth and span independent tensile strength ft and fracture toughness KIC
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Conservational integrals of the fourth-order phase field model for brittle fracture via Noether theorem Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-10 Fan Peng; Wei Huang; Zhi-Qian Zhang; Tian Fu Guo; Y.E. Ma; Yao Zhang
As a regularization method for modeling fracture phenomenon, the phase field method can not accurately capture the location of crack tip. J-integral is an important physical parameter to quantify the stress state of crack tip. In this study, the J-, M- and L-integrals of the fourth-order phase field model for brittle fracture are proposed based on the Noether theorem, and the corresponding infinitesimal
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Modelling delaminations using adaptive cohesive segments with rotations in dynamic explicit analysis Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-27 Jagan Selvaraj; Supratik Mukhopadhyay; Luiz F. Kawashita; Stephen R. Hallett
Multiple delamination planes can form when a composite structure is subjected to out-of-plane stresses during static over-loading or impact loading. Numerical modelling of such events is often prohibitively expensive because large numbers of cracks can co-exist and interact, and fracture models usually affect the time step size in explicit solutions. Here a new method called Adaptive Mesh Segmentation
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Experimental and numerical investigation on the effects of bedding plane properties on the mechanical and acoustic emission characteristics of sandy mudstone Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-05 Yaoyao Meng; Hongwen Jing; Xiaowei Liu; Qian Yin; Xingchen Wei
Bedding planes have a strong influence on the mechanical characteristics of layered rocks. To study the effects of bedding plane properties on the strength, fracture and acoustic emission (AE) characteristics of rock, Brazilian tests of sandy mudstone with different angles between the bedding plane inclination and loading direction (the bedding plane-loading angle) were first conducted. Based on the
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An analytical solution for the inverted four-point bending test in orthotropic specimens Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-02-05 Ilaria Monetto; Roberta Massabò
Analytical solutions are derived for interfacial energy release rate and mode mixity angle in the inverted four-point bending test. In the test, the loads applied in the classical four-point bending test are inverted so that the crack faces come into contact at the midspan and mode mixity with an important mode II component is produced. The contact forces are evaluated by employing a beam model and
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Anisotropic fracture and energy characteristics of a Tibet marble exposed to multi-level constant-amplitude (MLCA) cyclic loads: A lab-scale testing Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-23 Y. Wang; Y.F. Yi; C.H. Li; J.Q. Han
Rock mass is often subjected to complicated stress disturbance in many civil and mining engineering. This work aims to investigate the fatigue mechanical characteristics of marble having different interbed orientation subjected to multi-level constant-amplitude (MLCA) cyclic loads. The impacts of interbed structure on rock fracture and energy characteristics were investigated and characterized experimentally
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Numerical model of CO2 fracturing in naturally fractured reservoirs Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-20 Heqian Zhao; Kan Wu; Zhongwei Huang; Zhengming Xu; Huaizhong Shi; Haizhu Wang
Hydraulic fracturing becomes a key technology for unconventional oil and gas development. As a fracturing fluid, CO2 displays considerable advantages, particularly in shale gas exploitation. However, little research has quantitatively analyzed the effectiveness and efficiency of CO2 fracturing in naturally fractured reservoirs. In this study, a CO2 fracturing model is established in naturally fractured
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Fracture and failure behavior of additive manufactured Ti6Al4V lattice structures under compressive load Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-15 PeiYao Li; Yu E. Ma; WenBo Sun; Xudong Qian; Weihong Zhang; ZhenHai Wang
The additive manufacturing technology can be used to manufacture the complex lattice structures that are difficult to be fabricated by the traditional manufacturing technologies. In order to study the fracture and failure behavior of Ti6Al4V lattice structures manufactured by selective laser melting under compressive load, the cell topologies of face centered cubic with vertical struts (FCCZ) and body
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Experimental study on Fe-SMA-to-steel adhesively bonded interfaces using DIC Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-20 Wandong Wang; Ardalan Hosseini; Elyas Ghafoori
This study aimed to reveal the interface behavior of iron-based shape memory alloy (Fe-SMA) strips bonded to metallic substrates in order to ensure the integrity of such joints. A series of single lap-shear tests was performed on Fe-SMA-to-steel adhesively bonded joints. The test results reveal that the bond strength can reach over 70% of the tensile strength of the Fe-SMA and the cohesive failure
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Effects of span-depth ratios on the energy release rate for three-point bending beams Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-28 Yangyang Yin; Shaowei Hu
The effects of span-depth ratios on the energy release rate for three-point bending beams were examined. Expressions for the energy release rate for three-point bending specimens with various span-depth ratios were developed using linear interpolation method. The double-G fracture parameters were calculated through tests of three-point bending beams with the same span (800 mm) but various depths (100
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Defect-based fatigue life prediction of L-PBF additive manufactured metals Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Niloofar Sanaei; Ali Fatemi
Metal additive manufacturing (AM) while offering advantages such as generating parts with intricate geometries, introduces challenges such as intrinsic defects. Since fatigue cracks often start at defects, developing analytical methods to predict fatigue failure is necessary for critical AM applications involving cyclic loadings. In this work a computational framework is presented where a generalized
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Rubber cord adhesion inflation test: Effect of constitutive rubber model on evaluation of Gc Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-23 K. Kane; J. Jumel; A. Mbiakop-Ngassa; F. Lallet; Jean-Michel Vacherand; Martin E.R. Shanahan
The Rubber Cord Adhesion Inflation Test (RCAIT) is a recently proposed test protocol to study tyre rubber-steel cord fracture (Kane et al., 2019). As in the traditional blister test, a pressurised fluid is injected between the two adherends to propagate fracture. The fracture energy, Gc, is directly related to the strain energy stored in the inflated rubber. It was shown that evaluation of Gc for RCAIT
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Two-dimensional dynamic damage accumulation in engineered brittle materials Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-17 Brendan M.L. Koch; Calvin Lo; Haoyang Li; Tomoko Sano; Jonathan Ligda; James David Hogan
This paper details the dynamic materials testing of three advanced ceramics (CoorsTek Engineered Ceramics AD85 and AD995 alumina and a silicon carbide) and a cermet (Luminant TitanMade®) and discusses the observations of damage accumulation in these materials as they were strained to failure. Through the use of a Kolsky bar in conjunction with a Shimadzu HPV-X2 ultra-high-speed camera and Correlated
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Numerical analysis of NiTi actuators with stress risers: The role of bias load and actuation temperature Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-23 Pejman Shayanfard; Luděk Heller; Pavel Šandera; Petr Šittner
NiTi wires and thin ribbons are used in shape memory actuators as active elements undergoing repeated thermal cycles. The NiTi actuators operate either under constant force (CF loading constraint) or they act against a variable force (VF loading constraint) from an elastic bias spring. Any stress riser represents a danger for potential actuator failure upon cycling. Although NiTi actuators always include
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Early-age tensile constitutive relationships for steel and polypropylene fiber reinforced concrete Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Manjunath V. Bhogone; Kolluru V.L. Subramaniam
Early-age fracture tests are conducted on concrete beams with discrete steel, macro polypropylene and blends of macro and micro polypropylene fibers. The fracture behavior with aging of the concrete matrix containing 0.66% volume fraction of fibers is investigated at 1, 3, 7, and 28 days of age. The age-dependent multi-linear cohesive stress crack-separation (σ-w) relationship and the modulus of elasticity
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Ductile fracture of high strength steels with morphological anisotropy, Part I: Characterization, testing, and void nucleation law Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-27 Matthieu Marteleur; Julien Leclerc; Marie-Stéphane Colla; Van-Dung Nguyen; Ludovic Noels; Thomas Pardoen
The ductile fracture behavior of a high strength steel is investigated using a micromechanics-based approach with the objective to build a predictive framework for the fracture strain and crack propagation under different loading conditions. Part I of this study describes the experimental results and the determination of the elastoplastic behavior and damage nucleation under different stress triaxiality
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Fracture mechanics analysis of functionally graded materials using a mixed collocation element differential method Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-02 Jun Lv; Minghui Zheng; Bingbing Xu; Yongtong Zheng; Xiaowei Gao
In this paper, the fracture mechanics analysis in functionally graded materials and structures (FGMs) is presented. The elemental differential method, is extended to simulate the fracture behaviors of the functionally graded materials, in which the system of equations is established directly based on the equilibrium equations. The first and second order differentiations of the shape functions are utilized
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Thermo-chemo-mechanical cohesive zone model for cemented paste backfill-rock interface Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-20 Kun Fang; Mamadou Fall; Liang Cui
A thermo-chemo-mechanical cohesive zone model (CZM) is proposed to describe the shear behaviour of the interface between cemented paste backfill (CPB) and rock under the coupled effects of temperature and binder hydration. To quantitatively evaluate the thermal effect on the binder hydration, an equivalent thermal age is put forward to express the contribution of temperature to the mechanical properties
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Determination of crack extension resistance of concrete from boundary effect model Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Yanhua Zhao; Yang Liu; Bohan Xu
The fracture behavior of concrete can be described by an R-curve, which represents the ability of concrete to resist crack propagation. In this study, the R-curve is defined as the envelope of the energy release rates in the critical state and is constructed on the basis of the boundary effect model. Two fracture parameters are introduced for constructing the R-curve, namely, the fracture energy Gf
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A dynamic adaptive eigenfracture method for failure in brittle materials Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Zongyue Fan; Huming Liao; Hao Jiang; Hao Wang; Bo Li
We present a dynamic adaptive eigenfracture algorithm for the study of crack propagation in brittle materials. The original eigenfracture method is an variational approximation of the Griffith-type fracture with convergence as the element size vanishes. To improve its convergence rate, we extend the eigenfracture approach by using the effective energy release rate as the adaptive refinement criteria
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Fracture parameter analysis of flat shells under out-of-plane loading using ordinary state-based peridynamics Eng. Fract. Mech. (IF 3.426) Pub Date : 2021-01-21 Ming-Jyun Dai; Satoyuki Tanaka; Tinh Quoc Bui; Selda Oterkus; Erkan Oterkus
The present paper is devoted to numerical investigation on fracture parameters of cracked shells subjected to out-of-plane loading using ordinary state-based peridynamics (PD). The nonlocal deformation gradient and equivalent domain integral are introduced to evaluate fracture parameters. To reduce the surface effect and obtain more accurate results, the energy method and volume correction algorithm
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