Article
Mechanics
Xing-Yuan Miao, Renchao Lu, Xiao Chen
Summary: This study investigates the fracture behavior of sandwich structures with foam core slits using the phase-field method to simulate the complex fracture process. It is found that structures with resin-filled slits exhibit better fracture resistance and ductility. The study also examines the effects of the number of slits, slit spacing, and foam core density on load-carrying capacity and fracture resistance.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Marine
Qin Dong, Geng Xu, Yaoyu Hu, Ziya Peng
Summary: The main objective of this paper is to investigate the residual strength of a cracked plate considering fatigue crack propagation under cyclic loading. Factors such as crack length, number of cycles, tensile/compressive cyclic loads, and out-of-plane deformation are considered in the study of residual strength. The numerical results provide insight into the effect of crack propagation on structural residual strength, aiming to guide the evaluation of residual strength in cracked components.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Mechanics
Elias A. Toubia, Sangwook Sihn, Jeremey Pitz, Jonathan P. Vernon, Mark Flores, Stetson Parks
Summary: The study explores the thermal impact of laser processing on composite sandwich structures, investigating the effects on mechanical properties and failure modes based on different parameters. Thermal-induced damage significantly affects edgewise compression strengths and failure modes of the composite structures, as evidenced by experimental results and IR camera technology.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Aerospace
Siddarth Niranjan Babu, George A. Kardomateas
Summary: This paper presents closed-form expressions for the energy release rate and mode partitioning of face/core debonds in sandwich composites with orthotropic faces and core, by use of an elastic foundation analysis. The results are compared with finite element results and show very good agreement, demonstrating the effectiveness of the proposed method in capturing the behavior of debonds in sandwich composites.
Article
Nanoscience & Nanotechnology
Chunguo Zhang, Weidong Lu
Summary: This study clarifies the impact of overload on fatigue crack growth rate by enhancing the residual stress contribution behind and ahead of the crack tip and the relationship with crack closure effects. The results indicate that overload-induced residual stress contribution is a key factor in post-overload fatigue crack growth rate, exhibiting different mechanisms behind and ahead of the crack tip.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Mechanics
Xiu-Yang Fang, Hao-Nan Zhang, Dong-Wen Ma, Ze-Jian Wu, Wei Huang
Summary: By predicting the distribution of residual stress of welded rail and comparing the results, this study accurately evaluated the influence of welding residual stress on the fatigue crack propagation behavior of rail. The results showed significant differences in the subsurface crack type, path, rate, and lifetime between the cases with and without residual stress.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Multidisciplinary
Xuran Xiao, Volodymyr Okorokov, Donald Mackenzie
Summary: This paper proposes a method for predicting the high cycle fatigue life of cyclically loaded components with induced residual stress using standard S-N curve data, a fracture mechanics crack growth model, and Finite Element Analysis. The method is suitable for components with linear elastic working stress cycles and satisfying the requirements of LEFM and the SMART FEA method. The total fatigue life of the component is calculated by summing up the crack initiation life and crack propagation life.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2023)
Article
Engineering, Mechanical
Vinay Goyal, Jacob Rome, Dhruv N. Patel
Summary: An experimental and analytical study was conducted to understand the tensile failure mechanisms in asymmetrical tapered sandwich core structures at cold temperatures. The study revealed the significant influence of cure stresses in the foam, which should not be ignored, and successfully predicted the failure initiation location.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Mechanics
K. Tanaka, Y. Akiniwa
Summary: A modified strip-yield model is used to simulate plasticity-induced crack closure in the wake of advancing cracks, with different lengths of precracks, under fully reversed loading. Two types of precracks, open and closed, are examined to understand their effects on fatigue thresholds. The results show that the crack opening stress and effective stress intensity range Delta Keff have significant influence on fatigue thresholds, and new master curve equations are proposed for the cyclic R-curve.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
K. Tanaka, Y. Akiniwa
Summary: This study modifies a strip-yield model to simulate the plasticity-induced crack closure during crack extension from precracks with various lengths. The effects of precrack length and yield stress on fatigue thresholds are systematically examined.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Jordi Loureiro-Homs, Per Almroth, Frans Palmert, David Gustafsson, Kjell Simonsson, Robert Eriksson, Daniel Leidermark
Summary: The impact of crack closure effects on crack growth behavior was studied on Inconel 792 specimens under high temperatures, revealing that crack closure has a primary influence on crack growth behavior for this material. The crack closure behavior was successfully modeled using numerical simulations, including creep.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Jordi Loureiro-Homs, Per Almroth, Frans Palmert, David Gustafsson, Kjell Simonsson, Robert Eriksson, Daniel Leidermark
Summary: The crack growth behavior of CM 247 LC alloy was investigated under out-of-phase TMF and isothermal tests. Plasticity-induced crack closure was identified as the main mechanism, and an analytical model was proposed to approximate crack closure effects.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Civil
Yang Liu, Kin Shun Tsang, Nellian Alagu Subramaniam, John Hock Lye Pang
Summary: This study developed a structural fatigue life prediction model for thermite welded rail joints, utilizing a three-dimensional finite element model to investigate residual stresses and stress redistribution under cyclic loading. The results showed that failure to consider residual stress and relaxation could lead to an overestimation of fatigue crack propagation life by at least 50%.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Mechanical
Anbang Qu, Fanchun Li
Summary: This study analyzes the influence of 3D printing on the fatigue crack propagation life of a compressor impeller with a pressure ratio less than 3 under the combined action of 3D printing residual stress and external load. The impeller is printed using selective laser melting (SLM) technology and finite element method (FEM) is used to simulate the 3D printing process and analyze the residual stress and deformation. The results show that the research provides a basis for damage tolerance analysis of 3D printing compressor impeller and can serve as a reference for maintenance work.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Shuai Luan, Chunguo Zhang, Xing Zhang
Summary: This study clarifies the redistribution of residual stress (RS) during fatigue crack growth (FCG) in a welded joint. The results show that RS redistribution depends on the distance between the crack tip and the weld centerline, and the RS at the crack tip is always compressive. Additionally, the length of the contacted crack wake gradually increases, leading to a decrease in FCG rate.
MATERIALS & DESIGN
(2023)
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)