Article
Mechanics
Georgios Kotsinis, Theodoros Loutas
Summary: This study presents a closed form solution for calculating the strain energy release rate (SERR) at the initiation of a crack under dynamic loading conditions in a double cantilever beam (DCB) test. Finite element analysis was used to validate the analytical formulation, demonstrating the advantages of using the Timoshenko beam theory and considering crack tip root rotations in dynamic fracture mechanics.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Engineering, Mechanical
Taeseul Park, Asuka Kitahara, Toshiyuki Ishina, Shigeru Hamada, Hiroshi Noguchi
Summary: In this study, the current status of linear and nonlinear fracture mechanics was examined, and the requirements for elastic-plastic fracture mechanics (EPFM) as the next step in fracture mechanics were identified. The study proposed the use of imaginary crack tip opening displacement (I-CTOD) as a driving force for EPFM and conducted elastic-plastic finite element analyses of cracked solids in different work-hardened materials to understand the characteristics of the singular fields of elastic and plastic strains near a crack tip. It was found that I-CTOD represents the intensity of the singular fields of plastic strain, elastic strain, and imaginary plastic deformation near the crack tip in both plane stress and plane strain states. Therefore, I-CTOD shows promise as a mechanical driving force parameter for EPFM.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Nanoscience & Nanotechnology
Tingjing Geng, Hongfu Qiang, Zhejun Wang, Xueren Wang, Chunguo Yue
Summary: This study investigates the mechanical properties and damage mechanism of hydroxyl-terminated polybutadiene (HTPB) solid propellants under biaxial compression through experimental testing and microscale analysis. The results show that the biaxial compression mechanical curves of HTPB propellants exhibit strong nonlinear characteristics and are significantly influenced by the strain rate.
Article
Construction & Building Technology
Zahra Khaji, Mahdi Fakoor
Summary: A new criterion based on maximum strain energy release rate is proposed in this study, which meaningfully links the dissipated energy of FPZ to macroscopic fracture by defining stress intensity factors. The criterion can evaluate the effects of FPZ on the fracture behavior of orthotropic material.
STEEL AND COMPOSITE STRUCTURES
(2022)
Article
Engineering, Mechanical
Ritika Singh, Subir Das
Summary: This article investigates the behavior of an arbitrary oriented crack that crosses the interface under thermo-mechanical loading. Mathematical methods are used to derive the expressions of stress intensity factors (SIFs) and strain energy release rates (SERRs) of the crack, and the results are validated. Graphical presentations are provided to better understand the behavior of the crack under different parameters.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Chunjiang Zou, Jianchun Li, Xiaobao Zhao, Jian Zhao
Summary: Dynamic loading significantly affects the mechanical properties and cracking behaviors of rocks, with tensile strength being more sensitive to strain rate and tensile cracks being suppressed. The model proposed in this paper successfully explains the difference in fracturing behaviors under quasi-static and dynamic loadings. The well-correlation between experimental and modelling results indicates the potential of the model to quantitatively analyze complex macroscopic problems involving high strain rates.
EXTREME MECHANICS LETTERS
(2021)
Article
Mechanics
Yanfei Niu, Haoliang Huang, Jiangxiong Wei, Chujie Jiao, Qiangqiang Miao
Summary: The study investigates the fatigue crack propagation behavior in ultra-high-performance concrete (UHPC) containing different volume fractions of steel fibers under cyclic flexural loading. Different UHPC specimens exhibit varying critical crack lengths and propagation rates, with strain diagrams showing distinct patterns for crack growth. The research highlights the importance of reducing applied stress level and increasing steel fiber reinforcement to enhance fatigue life.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Yao-Min Li, Bin Zhang
Summary: Crack branching in graphene under complex stresses is investigated using molecular dynamics simulations and boundary-layer models. By considering the anisotropic fracture toughness of hexagonal graphene, a Wulff-like curve is plotted based on the maximum energy release rate (MERR) criterion, showing the direction of crack kinking is consistent with that of the weak fracture toughness along the zigzag edge. The angle of crack kinking prefers 0 degrees /30 degrees /60 degrees, contrary to the angle predicted by the maximum circumferential stress criterion. The T-stress along the crack front, obtained through the over-deterministic method, can indicate the possibility of kink formation, especially for zigzag cracks. This study incorporates the Wulff-like curve and MERR criterion to accurately predict nanocrack paths in graphene.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
A. Ince, G. Glinka
Summary: Several studies have indicated that fatigue crack growth is influenced by elastic-plastic strains and stresses localized near the crack tip. The distribution of stress and strain ahead of the crack tip is crucial in crack growth analysis of structural components. While numerical analysis methods can be used to compute local stresses and strains, they are costly and labor-intensive in engineering applications. Therefore, a new modeling framework based on approximation has been developed to calculate elastic-plastic stresses and strains ahead of a stationary crack tip, which has been verified through numerical finite element analysis data.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Meiling Xu, Yujin Liu, Huang Yuan
Summary: In this study, the applicability of the delta J-integral under the Masing postulate was computationally investigated. The results confirm that delta J has a more severe path-dependency than the delta J-integral under incremental plasticity. Additionally, it was found that the stress range field can be characterized by delta J, but not the strain field under fatigue loading. The delta J dominant zone is much smaller than the HRR zone and decreases further with applied loading.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Ye Zhang, Kazuki Fukao, Takahiro Matsuda, Tasuku Nakajima, Katsuhiko Tsunoda, Takayuki Kurokawa, Jian Ping Gong
Summary: Double network (DN) gels have significant resistance to crack initiation and propagation in highly stretched states. The crack growth velocity in DN gels exhibits a power-law relationship with the bulk energy release rate. Necking DN gels show a threshold behavior in which crack propagation transitions from slow to fast mode once the energy release rate exceeds a certain value.
EXTREME MECHANICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Marco Boecker, Harish Ramesh Babu, Sebastian Henkel, Mario Raddatz, Uwe Gampe, Horst Biermann
Summary: The planar-biaxial thermo-mechanical fatigue behavior of nickel-base superalloy Inconel 718 was studied under selected loading conditions, and the deformation and lifetime behavior were analyzed and compared with high-temperature isothermal low-cycle fatigue tests.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Engineering, Mechanical
Ilari Tillikainen, Pasquale Gallo, Pauli Lehto, Heikki Remes
Summary: The study investigates the relationship between crack growth rate (CGR) and cyclic crack-tip opening displacement (ΔCTOD) of microstructurally small fatigue cracks using high-resolution digital image correlation (DIC). Load-controlled fatigue tests were performed on small-scale specimens of 18%Cr ferritic stainless steel. The findings reveal that the non-linear relationship between CGR and ΔCTOD on a double logarithmic scale is caused by the crack-tip bypassing an inhomogeneous shear strain localization zone. ΔCTOD is not able to characterize the behavior of microstructurally small fatigue cracks within this zone, but remains a valid crack driving force parameter outside it.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Composites
Yu Gong, Yuting Gao, Zhaobin Li, Wenjuan Lin, Jianyu Zhang, Libin Zhao, Ning Hu
Summary: In this study, the authors analyzed the distribution of strain energy release rate (SERR) at the crack front of carbon fiber-reinforced polymer laminates with elastic coupling using the edge ring crack torsion (ERCT) test configuration. They calculated the SERR at the delamination front using the virtual crack closure technique (VCCT). The results showed that the distribution of SERR was significantly influenced by elastic coupling and stacking sequence, and that better uniformity of SERR distribution could be achieved in specific laminates.
POLYMER COMPOSITES
(2023)
Article
Construction & Building Technology
Hao Qiu, Binglun Chen, Fei Wang, Feiyu Liao, Meng Wang, Duanying Wan
Summary: In this study, the mechanical properties of the mortar-rock interface were investigated using a split Hopkinson pressure bar (SHPB) experiment and numerical simulation. The results showed that the interface crack growth rate in the BSCT specimen was lower than the waves in the M40 mortar, and as the loading rate increased, the fracture properties of all specimens were significantly improved, especially for the specimens with rough interfaces.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Physical
Tam T. Mai, Chi Nhan Ha Thuc, Huy Ha Thuc
FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES
(2015)
Article
Polymer Science
Thanh-Tam Mai, Yoshihiro Morishita, Kenji Urayama
Article
Chemistry, Physical
Thanh-Tam Mai, Yoshihiro Morishita, Kenji Urayama
Article
Polymer Science
Thanh-Tam Mai, Takahiro Matsuda, Tasuku Nakajima, Jian Ping Gong, Kenji Urayama
Article
Polymer Science
Vu Ngoc Khiem, Thanh-Tam Mai, Kenji Urayama, Jian Ping Gong, Mikhail Itskov
Article
Polymer Science
Thanh-Tam Mai, Kenichiro Okuno, Katsuhiko Tsunoda, Kenji Urayama
Article
Engineering, Mechanical
Rui Xiao, Thanh-Tam Mai, Kenji Urayama, Jian Ping Gong, Shaoxing Qu
Summary: Studies on the anisotropic damage behaviors of double network hydrogels under multi-axial deformation conditions have been conducted. Results indicate that the non-affine microsphere model accurately predicts directional damage of the primary cross-linked network and captures important features of experimental observations. This developed theoretical framework can enhance the fundamental understanding of anisotropic damage behaviors in various types of tough gels.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
Thanh-Tam Mai, Kenichiro Okuno, Katsuhiko Tsunoda, Kenji Urayama
Summary: The crack growth behavior of filler-reinforced elastomers is significantly complex due to the simultaneous directional stress softening. Directional stress softening reduces the threshold tearing energy for crack propagation and increases local strain in the direction of softening.
MECHANICS OF MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Yuga Taniguchi, Thanh-Tam Mai, Masashi Yamaguchi, Katsuhiko Tsunoda, Kenji Urayama
Summary: The Mullins effect refers to the phenomenon in which the stress in elastomer/filler composites decreases significantly during unloading or second loading. This study investigated the Mullins effect in carbon-black reinforced elastomers by measuring mechanical stresses and electrical conduction under different biaxial stretching. The results showed that small equibiaxial strain caused a significant increase in electrical resistivity, indicating the breakdown of the initial conductive carbon-black network. The residual destruction of the carbon-black network increased with biaxial strain for small deformations, but saturated at large deformations.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Ryosuke Osumi, Tomohiro Yasui, Ruito Tanaka, Thanh-Tam Mai, Hideaki Takagi, Nobutaka Shimizu, Katsuhiko Tsunoda, Shinichi Sakurai, Kenji Urayama
Summary: This study investigates the hardening mechanism of elastomers under tensile deformation, finding that crack propagation velocity increases with stretch and leads to crystallization-driven hardening; the characteristics of crack tips also undergo significant changes during this process.
Article
Engineering, Mechanical
Mahrez Saadedine, Fahmi Zairi, Nourdine Ouali, Thanh-Tam Mai, Kenji Urayama, Abderrahman Tamoud, Amar Mesbah
Summary: This article addresses the problem of representing the multiaxial inelastic behavior of elastomeric particulate composites at different scales. A three-dimensional model is proposed to describe the multiaxial inelastic response and reinforcement mechanisms. The effects of multiaxiality and inelasticity are considered using a network decomposition based on the tube confinement theory. The model successfully reproduces the significant features of the multiaxial macro-response and provides insights into the role of reinforcement mechanisms in multiaxial dissipation.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Mechanics
Thanh-Tam Mai, Yuga Taniguchi, Katsuhiko Tsunoda, Kenji Urayama
Summary: The anisotropy of internal damage in carbon-black filled styrene butadiene rubber was investigated. It was found that there was little anisotropy in moderate stretching, but significant anisotropy in higher stretching, comparable to that in silica filled SBR.
NIHON REOROJI GAKKAISHI
(2023)
Article
Chemistry, Multidisciplinary
Soichiro Hiraiwa, Thanh-Tam Mai, Katsuhiko Tsunoda, Kenji Urayama
Summary: This study reveals the strain hardening due to strain-induced crystallization (SIC) in both cross-linked natural rubber (NR) and its synthetic analogue (IR) under planar extension. The research shows that evident strain hardening due to SIC is observed in both stretching and constrained directions when the stretch exceeds a critical value. The study also finds a distinct minimum in the nominal stress ratio as a function of stretch, indicating a reversed relationship between the increment of stress in the stretching and constrained directions. Furthermore, the investigation provides valuable insights for predicting the mechanical response of SIC rubber under different deformation conditions.
Article
Chemistry, Physical
Thanh-Tam Mai, Takahiro Matsuda, Tasuku Nakajima, Jian Ping Gong, Kenji Urayama
