Article
Materials Science, Ceramics
Roman Papsik, Oldrich Sevecek, Eric Martin, Raul Bermejo
Summary: Crack initiation in brittle materials upon spherical indentation is influenced by tensile radial stresses during loading. The location of crack onset often differs from the site of maximal stress. The initiation forces and location of crack onset depend on geometrical parameters and surface condition. A coupled stress-energy fracture criterion is introduced in this work to describe the initiation of ring cracks in brittle materials, considering the geometry of the contact and the material's inherent strength and fracture toughness. The criterion can explain the location offset of the ring crack upon loading and predict the initiation force, provided surface compressive stresses are considered. The criterion can also estimate the surface residual stress of ceramic parts based on contact damage experiments.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Martin Pletz, Florian Josef Arbeiter
Summary: This study develops a numerical model to predict toughening mechanisms and damage tolerances in multi-layer materials by examining phenomena such as crack initiation and growth.
Article
Mechanics
Haijun Wang, Hanzhang Li, Lei Tang, Chun Zhu, Xuhua Ren, Yafei Qiao, Gan Feng
Summary: The propagation and fracture characteristics of internal cracks in SCB tests were investigated. Through numerical simulations and experimental verification, it was found that the presence of internal cracks significantly reduces the failure load of the samples.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Pengfei Jia, Kai Huang, Hongjun Yu, Takahiro Shimada, Licheng Guo, Takayuki Kitamura
Summary: This paper proposes a novel atomic J-integral calculation method, which calculates the local displacement gradient and stress field for discrete models, and verifies its effectiveness and path-independency. It is also confirmed that this method is dimension-independent even at ultra-small scales.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Multidisciplinary
Leo Morin, Amit Acharya
Summary: This study develops a computational model for arbitrary brittle crack propagation within a fault-like layer in a 3D elastic domain, and analyzes its associated quasi-static and dynamic fields. The model utilizes FFT-based solver for linear momentum balance and a Godunov-type projection-evolution method for crack evolution equation. Applications of the model include exploring equilibria, irreversibility, strength and toughness criteria, and crack propagation under different loading conditions.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Chemistry, Physical
Gennady Kolesnikov, Vitali Shekov
Summary: This article discusses the prediction of brittle fracture in rocks and similar materials, and presents a fracture criterion based on an energy approach. The validity of this criterion in engineering calculations is confirmed through experimental data.
Article
Construction & Building Technology
Mina Iskander, Nigel Shrive
Summary: Flaws play a crucial role in crack initiation and propagation in solids. The geometry of pre-existing flaws and the position of secondary voids can significantly impact crack propagation. The study provides insights into the effects of porosity on compressive strength and Strain Gradient Effect in materials like concrete and masonry.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Mechanical
Shuang Li, Haining Lu, Yanli Jin, Pengfei Sun, Xiaohua Huang, Zhiwu Bie
Summary: The study proposed an improved dual-parameter PD model (UDPD) to address the issues in damage and fracture analysis of quasi-brittle materials. Through numerical tests and comparisons, it was found that the model has simplicity and stability, and can effectively capture the nonlinear deformation and progressive failure of quasi-brittle materials with different Poisson's ratios.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Multidisciplinary Sciences
Gennady Kolesnikov, Maria Zaitseva, Aleksey Petrov
Summary: The relevance of problems related to fracturing in engineering materials and structures remains significant over time. In this study, the focus is on modifying an analytical model to predict strength and the full load-displacement (or stress-strain) curve using only pre-peak loading. The results of the study are consistent with experimental findings.
Article
Mechanics
Benhour Amirian, Hossein Jafarzadeh, Bilen Emek Abali, Alessandro Reali, James David Hogan
Summary: This paper proposes a theoretical-computational framework to predict the failure behavior of two anisotropic brittle materials. The framework uses constitutive equations derived from thermodynamics to establish a fully coupled twin and crack system. The results are validated using finite element simulations and experimental data.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Mechanics
Yifeng Chen, George G. Adams, David A. Hills
Summary: This paper analyses fracture with a finite-height crack, predicting the fracture location and providing a practical example.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Mechanics
Lingyue Ma, Roberto Dugnani
Summary: Phase-field simulations were used to investigate the unstable crack propagation in brittle plates fractured in bending. The study found that the crack front in unstable cracks was nearly elliptical when the cracks were relatively short, with depths less than half the plate's thickness. The intersection angles between the crack front and the free surface were typically 88 degrees +/- 6 degrees. Higher Poisson's ratios resulted in more oblong cracks but had no obvious effects on the intersection angles. The evolution of the crack shape was unaffected by the plate's finite width up to crack lengths equal to 80% of the plate's width.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mechanics
Gili Lifshitz Sherzer, Younes Fadakar Alghalandis, Karl Peterson
Summary: In this study, we have developed innovative improvements to the Lattice Discrete Particle Model (LDPM) that enable accurate simulation of aggregate fracturing in concrete. By comparing the simulation results with scans of actual cracking, we have achieved matching fracturing patterns. Furthermore, our method has demonstrated good fits for the brittleness of High Strength Concrete (HSC) when compared with experimental results for a three-point bending beam with a notch.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Zhitao Zhang, Haijun Wang, Lingwei Zhong, Lei Tang
Summary: In this study, pure closed internal cracks were generated on glass using 3D Internal Laser-Engraved Crack (3D-ILC) technology, and uniaxial compression tests were conducted. The results showed that the failure of the glass specimens originated from the pre-existing internal crack, which generated wing cracks and eventually led to specimen failure. This test method is significant in studying crack propagation, failure characteristics, and characteristic load of brittle materials.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Nanoscience & Nanotechnology
Murat Yaylaci
Summary: This study examines the elastic plane problem of a layered composite with an internal or edge crack perpendicular to its boundaries. Numerical analysis using the Finite Element Method (FEM) is employed, and the results are compared with analytical solutions to validate the model. The findings indicate a perfect agreement between the numerical and analytical results.
ADVANCES IN NANO RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
P. Cornetti, A. Sapora
INTERNATIONAL JOURNAL OF FRACTURE
(2019)
Article
Mechanics
M. Munoz-Reja, P. Cornetti, L. Tavara, V Mantic
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2020)
Article
Engineering, Mechanical
Alberto Sapora, Pietro Cornetti, Alberto Campagnolo, Giovanni Meneghetti
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2020)
Article
Engineering, Mechanical
M. Munoz-Reja, L. Tavara, V Mantic, P. Cornetti
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2020)
Article
Materials Science, Multidisciplinary
Aurelien Doitrand, Pietro Cornetti, Alberto Sapora, Rafael Estevez
Summary: Experimental and numerical investigations were conducted on mixed mode crack initiation in PMMA specimens containing square holes, revealing that crack deflection and failure load increase with decreasing hole sizes, corresponding to higher mode mixities. The Finite Fracture Mechanics approach successfully captured this behavior with good agreement between blind predictions and recorded data.
INTERNATIONAL JOURNAL OF FRACTURE
(2021)
Article
Mechanics
A. Sapora, G. Efremidis, P. Cornetti
Summary: Two nonlocal approaches, Gradient Elasticity and Finite Fracture Mechanics, are applied to analyze the behavior of a circular hole in an infinite elastic medium under remote biaxial loading and internal pressure. While GE is nonlocal in material behavior and local in failure criterion, FFM is local in material behavior and nonlocal in fracture criterion. Both approaches involve a characteristic length and can lead to almost identical critical load predictions when the internal lengths are properly related.
Article
Engineering, Mechanical
A. Chao Correas, M. Corrado, A. Sapora, P. Cornetti
Summary: This study investigates the decrease of apparent uniaxial tensile strength resulting from a single flawless spherical cavity in an infinite linear elastic continuum under uniaxial tension. A new generalized semianalytical expression for the stress intensity factor of an annular crack surrounding the spherical cavity is proposed and validated. The apparent tensile strength is estimated by four different approaches, showing good correlation with theoretical predictions, experimental data, and atomistic simulations.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Chemistry, Physical
Amir Mohammad Mirzaei, Mauro Corrado, Alberto Sapora, Pietro Cornetti
Summary: This study investigates interfacial debonding in fiber-reinforced composites using different models and methods to analyze load values and maximum load values in direct shear tests, and proposes effective bond length formulas.
Article
Engineering, Mechanical
P. Cornetti, M. Munoz-Reja, V Mantic
Summary: In this paper, several analytical models describing the single-lap shear test are reviewed and compared. These models are one-dimensional and formulated under the assumption of pure mode II cracking process. The effective bond length estimates provided by different models are compared and compared with the ones present in Design Codes. Finally, a comparison with experimental data sets available in the Scientific Literature is also provided.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
Francesco Ferrian, Pietro Cornetti, Liviu Marsavina, Alberto Sapora
Summary: Finite Fracture Mechanics and Cohesive Crack Model can predict the strength of structural components effectively, overcoming the limitations of Linear Elastic Fracture Mechanics. The present study aims to investigate size effects by expressing each model as a unified system of equations, describing stress requirement and energy balance. Two different structural configurations are considered for brittle crack onset, and the study is performed using a semi-analytical parametric approach. The theoretical strength predictions are validated with experimental results and estimations by the point criterion in the framework of Theory of Critical Distances.
FRATTURA ED INTEGRITA STRUTTURALE-FRACTURE AND STRUCTURAL INTEGRITY
(2022)
Article
Materials Science, Multidisciplinary
A. Chao Correas, P. Cornetti, M. Corrado, A. Sapora
Summary: The coupled criterion of Finite Fracture Mechanics (FFM) has been extended to dynamic loadings by introducing the Dynamic extension of FFM (DFFM) model. The DFFM model accurately predicts the rate dependence of failure initiation in brittle and quasi-brittle materials by considering the coalescence period of microcracks and the relationship between external solicitation, dynamic stress field, and energy release rate.
INTERNATIONAL JOURNAL OF FRACTURE
(2023)
Article
Engineering, Mechanical
Francesco Ferrian, Arturo Chao Correas, Pietro Cornetti, Alberto Sapora
Summary: This study investigates the failure size effect of a spheroidal void in an infinite linear elastic solid under remote tension using the coupled Finite Fracture Mechanics (FFM) approach. The opening stress field and stress intensity factor (SIF) of an annular crack are obtained numerically through finite element analyses (FEAs), and semi-analytical functions approximating the stress concentration factor and SIF are proposed. The failure size effect on spheroidal voids is reported and compared with experimental results, showing a good agreement with FFM predictions.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Alberto Sapora, Pietro Cornetti, Alberto Campagnolo, Giovanni Meneghetti
Summary: In this study, the coupled stress-energy criterion of Finite Fracture Mechanics (FFM) was applied to evaluate the fatigue limit of structures weakened by sharp V- and U-notches under mode I loading conditions. It was found that the FFM method requires consideration of material fatigue limits, stress intensity factor range thresholds, structural parameters, and notch geometry.
INTERNATIONAL JOURNAL OF FRACTURE
(2021)
Proceedings Paper
Engineering, Civil
Alberto Sapora, Pietro Cornetti, Alberto Campagnolo, Giovanni Meneghetti
1ST VIRTUAL EUROPEAN CONFERENCE ON FRACTURE - VECF1
(2020)
Proceedings Paper
Construction & Building Technology
Alberto Sapora, Pietro Cornetti, Alberto Campagnolo, Giovanni Meneghetti
25TH INTERNATIONAL CONFERENCE ON FRACTURE AND STRUCTURAL INTEGRITY
(2019)
Article
Mechanics
Xiaolong Liu, Kelian Luo, Pengcheng Gao, Tao Cong, Xi Wang, Wenjing Wang
Summary: This paper investigates the formation mechanisms of the zig-zag crack region on the shattered rim of railway wheels. The zig-zag crack region, identified as a typical region for crack propagation in rolling contact fatigue behavior, was observed using scanning electron microscopy and transmission electron microscopy. The formation of the zig-zag morphology is attributed to the periodic deflection of the propagation path relative to the initial propagation plane, caused by the limited plastic deformation zone at the crack tip. Grain refinement and secondary cracks in the zig-zag crack region are a result of the large compressive and shear stresses induced by rolling contact loading.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Anastasia Iziumova, Aleksei Vshivkov, Ivan Panteleev, Virginia Mubassarova, Oleg Plekhov, Denis Davydov
Summary: The aim of this study was to investigate the correlation between structural, acoustic emission, and thermal characteristics of fatigue crack growth in titanium alloys. Cluster analysis of the acoustic emission signals revealed two different types of signals observed during the fatigue crack development. It was experimentally demonstrated that the stored energy tends to reach an asymptotic value at the final stage of fatigue crack growth and this is correlated with the twinning process intensification in titanium alloy Ti Grade 2. A correlation was assumed between the stages of change in heat flux, the cumulative energy of the first cluster of acoustic emission signals, and the crack length.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
M. Vieira de Carvalho, I. A. Rodrigues Lopes, F. M. Andrade Pires
Summary: This study investigates the numerical challenges of fracture mechanics models within implicit quasi-static frameworks and proposes an instability criterion. The ratio of cohesive to internal power is identified as a crucial factor. Two strategies for handling fracture problems with instabilities are discussed and a comparative assessment is performed. The study also examines more complex material responses, including transformation-induced plasticity effects.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Thomas Duminy, Aurelien Doitrand, Sylvain Meille
Summary: This study conducted in situ wedge splitting tests on millimeter-size PMMA samples and proposed a method to determine the material tensile strength and critical energy release rate using digital image correlation and a full finite element implementation of the coupled criterion.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Xin Chang, Xingyi Wang, Chunhe Yang, Yintong Guo, Yanghui Wan
Summary: The influence of cyclic thermal shock and high-temperature acid etching on the Mode I fracture of shale was investigated in this study. It was found that cyclic thermal shock severely degrades the strength and fracture toughness of shale, while high-temperature acid etching treatment improves the fracture toughness. These findings are valuable for optimizing process parameters to reduce initiation pressure in deep shale formations.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Liaojun Yao, Mingyue Chuai, Zhangming Lyu, Xiangming Chen, Licheng Guo, R. C. Alderliesten
Summary: Methods based on fracture mechanics have been widely used in fatigue delamination growth (FDG) characterization of composite laminates. This study proposes appropriate similitude parameters to represent FDG behavior with different R-ratios.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Zesheng Zang, Zhonghui Li, Yue Niu, Shan Yin
Summary: This study conducted experiments and recorded signals to investigate the fracture behavior and damage evolution characteristics of coal samples. The results showed that as loading proceeds, the stress, electric potential (EP), and acoustic emission (AE) values increase, and EP and AE signals are excited when stress drops. The fracture behavior of coal samples is altered by flaw inclination, and the destruction mode becomes increasingly complicated. The damage evolution characteristics of coal samples can be evaluated and analyzed by defining the coefficient of variation (CV value) of EP and the b value of AE.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Clotilde Berdin, Nathalie Prud'homme
Summary: In this study, zirconia layers with different fractions of tetragonal phase and thicknesses were tested for multi-cracking behavior. Cracks perpendicular to the tensile direction were observed, showing a blunting effect into the substrate. The ratio of crack spacing at saturation to layer thickness decreased as the layer thickness increased. Unit cell modeling was used to establish a relationship between crack spacing and layer strength, which fell within the bounds of Hu and Evans model and was found to be insensitive to the tetragonal zirconia fraction.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Huadong Zhang, Weichen Kong, Y. H. Liu, Yuh J. Chao
Summary: Williams' series expansion crack tip solution in linear elasticity is modified to include a uniform crack face pressure. Practical methods to calculate T-stress from near crack tip stresses are outlined. The analytical results are consistent with numerical results.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Jiahao Kong, Haoyue Han, Tao Wang, Guangyan Huang, Zhuo Zhuang
Summary: This paper introduces a phase-field model for polymer foam materials by combining the phase-field method with the crushable foam model. The model is calibrated using experimental data and successfully simulates the fracture processes of polyurethane under different loading conditions. The study is important for the engineering applications of polymer foam materials.
ENGINEERING FRACTURE MECHANICS
(2024)
