Article
Mechanics
Yun Jia, Xiaolong Zhao, Hanbing Bian, Wei Wang, Jian-Fu Shao
Summary: This paper focuses on the hydro-mechanical behavior of concrete under high confining pressures. By conducting hydrostatic compression tests and quasi-oedometric tests, it is found that the mechanical behavior of concrete is strongly influenced by its hydraulic responses.
MECHANICS RESEARCH COMMUNICATIONS
(2022)
Article
Construction & Building Technology
Weipei Xue, Linfeng Xu, Zhongjian Wang, Tong Min, Jun Xu
Summary: This study investigates the effects of service loading and dry-wet-freeze-thaw environments on the initial damage of concrete by conducting permeability testing and microscopic characterization under varying confining pressure. The results show that permeability exhibits nonlinear characteristics during the loading and unloading process. The initial permeability increases with increasing load level and the number of dry-wet-freeze-thaw cycles. The study also reveals the evolution pattern and mechanism of specimen permeability using various analysis techniques.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Qiang Fu, Wenrui Xu, Dan Li, Ning Li, Ditao Niu, Lu Zhang, Bingbing Guo, Yongli Zhang
Summary: The study investigated the dynamic compressive behavior of HBPRC under confining pressure, showing strain rate and confining pressure dependence. The addition of basalt and polypropylene fibers can reduce failure degree of concrete and improve shear failure feature. Furthermore, the study established an empirical dynamic strength criterion for HBPRC considering the effects of fiber and pore structure.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Materials Science, Multidisciplinary
Xiaoli Wei, Xiaodan Ren
Summary: The purpose of this paper is to develop a confinement enhanced damage-plasticity model for concrete that can characterize the improvement of strength and ductility under high confining stress. The influence mechanisms of confinement in damage and plasticity sub-space are discussed separately. The proposed models are validated through comparison with experimental results.
MECHANICS OF MATERIALS
(2023)
Article
Construction & Building Technology
Jijing Wang, Hualin Zhang, Shuangxing Qi, Hanbing Bian, Xinbo Duan, Biao Long
Summary: This study investigates the micro-damage mechanism of silty mudstone through the use of nano-materials and a triaxial unloading test considering multiple paths. The results show that the initial deviatoric stress affects the peak stress, residual stress, and residual strain of the mudstone, while crack propagation on the fracture surface during unloading is influenced by both confining pressure and initial deviatoric stress. The impact of confining pressure on pore morphology diminishes as the confining pressure and initial deviatoric stress increase. In addition, the fractal dimension increases with increased confining pressure and initial deviatoric stress, leading to a transition in the pore surface from smooth to rough.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Engineering, Aerospace
Tianpeng Li, Junli Han, Shixin Wang, Yong He, Xiong Chen, Bang Lu
Summary: The mechanical properties of N15 solid propellant are influenced by the confining pressure, which can enhance the maximum tensile strength and inhibit crack extension by reducing particle dewetting and delaying hole propagation. The constitutive model accurately describes the impact of confining pressure on the mechanical properties of N15 propellant.
INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING
(2021)
Article
Mechanics
Rong-xin Peng, Wen-liang Qiu, Meng Jiang
Summary: This paper establishes a micro-scale modeling framework for frozen damage of concrete, considering the micro-structural characteristics. It predicts the pore evolution and macro-mechanical behavior of concrete during freeze-thaw cycles. The research shows that the degradation of concrete's performance is mainly caused by stiffness degradation and increase in porosity.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Weipei Xue, Wei Jing, Zhongjian Wang, Hanwen Zhang, Jian Lin
Summary: This study investigates the mechanical behavior, permeability evolution, and deformation failure mechanism of lining concrete under pore water pressure in underground concrete structures. Results show that an increase in pore water pressure leads to the coupling of seepage and stress fields in concrete, causing microcracks to propagate and decreasing concrete strength and elastic modulus. Permeability exhibited three trends: gradual decrease, stable development, and sharp increase, closely related to pore number and microcrack development. A triaxial compression infiltration constitutive model was derived for concrete. This study guides the design of lining concrete structures in underground engineering.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Engineering, Mechanical
Shufeng Shi, Xiangzhen Kong, Qin Fang
Summary: A plastic-damage material model is proposed for foam concrete to capture its mechanical behavior under high pressures. The model introduces a closed form yield function, a partially-associative flow rule, and a new piecewise hardening law, as well as considers the strain-rate effect and irreversible degradation caused by microcrack growth and pore collapse. Numerical evaluations and blast response predictions demonstrate the accuracy of the model in predicting complex failures of foam concrete.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Engineering, Geological
Xu Chen, Minggao Tang, Chun'an Tang
Summary: The study investigated the effect of confining pressure on damage evolution and failure behaviors of intact sandstone samples under cyclic disturbance. It was found that both the duration and number of cycles positively correlate with confining pressure, impeding crack formation and reducing damage during cyclic disturbance. Increasing confining pressure resulted in more flaking and exfoliation of rock samples after the cyclic disturbance tests.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Construction & Building Technology
Weipei Xue, Xiaochen Mao, Wei Xu, Hanwen Zhang, Cong Gao
Summary: This study investigates the impact dynamic properties and pore structure characteristics of shaft lining concrete after exposure to various water pressure levels and durations. The results show that the impact strength increases when the damage effect induced by microcracks and micropores expansion under water pressure is less than the enhancement benefit under impact dynamic load, and vice versa.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Engineering, Geological
Long Yan, Weiya Xu, Rubin Wang, Huanling Wang, Wei-Chau Xie
Summary: This paper presents an experimental study on the mechanical behavior and permeability evolution of basalt under hydro-mechanical coupling conditions. The relationship between confining pressure and steady creep rate was described by an exponential function, while the evolution of permeability exhibited phased characteristics. These results provide insights for the long-term stability assessment of basalt under coupled hydro-mechanical conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Manufacturing
Yekai Yang, Chengqing Wu, Zhongxian Liu, Hai Zhang
Summary: This study presents an experimental investigation of the triaxial behavior of 3D-printing ultra-high performance fiber-reinforced concrete (3DP-UHPFRC) and compares it with mold-casting ultra-high performance fiber reinforced concrete (MC-UHPFRC). The results show that 3DP-UHPFRC has similar failure modes, mechanical properties, and failure criteria as MC-UHPFRC. Additionally, the fitting effect of the Mohr-Coulomb failure criterion on 3D-printing specimens without steel fiber is poor, while the Power-law and Willam-Warnke failure criteria are suitable for all 3D-printing specimens.
ADDITIVE MANUFACTURING
(2022)
Article
Construction & Building Technology
Chenghuan Lin, Jikai Zhou
Summary: In this study, a prediction model is proposed to accurately predict the peak strengths of concrete under equal or unequal triaxial compression for different strength grades, types, or shapes. The model is developed based on the concept of equivalent confining stress and evaluated using a rich experimental database. The results show that the proposed model can provide accurate predictions for concrete under uniform or non-uniform triaxial compression.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Energy & Fuels
Deyi Gao, Shuxun Sang, Shiqi Liu, Wenkai Wang, Hang Mo
Summary: Conventional and cyclic unloading tests were conducted to study the effects of unloading patterns and rates on the deformation characteristics and mechanical properties of tectonic coal. The results showed that a lower unloading rate promoted circumferential strain but inhibited axial strain under continuous unloading. In the cyclic unloading path, a lower unloading rate promoted volume expansion, and the strains increased with the unloading levels but decreased with the number of cycles. The tangential modulus and Poisson ratio were proportional to the unloading rate, and the cyclic unloading pattern delayed and inhibited damage expansion, resulting in higher mechanical strength and more structurally stable tectonic coal responses compared to continuous unloading.
Article
Engineering, Geological
Yulong Zhang, Jianfu Shao, Zaobao Liu, Chong Shi
Summary: This paper presents a numerical study on the dynamic behavior of rock avalanches, focusing on the influence of particle shape, size, and gradation on velocity and energy transformation process of falling rock clusters.
Article
Engineering, Multidisciplinary
Meng Wang, Fabrice Cormery, Wanqing Shen, Jianfu Shao
Summary: In this study, a new phase-field model is developed to simulate complex cracking processes in rock-like materials under various loading paths. Both smooth frictionless and rough frictional cracks are investigated. For smooth cracks, an elastic-damage model is formulated with the unilateral effect on the elastic stiffness tensor. For rough cracks, an elastic-plastic damage model is developed, incorporating the damage evolution explicitly coupled with frictional sliding along cracks. The proposed model properly considers the dependency of mechanical behavior on the confining stress of geological materials under compressive stresses by incorporating the friction sliding mechanism.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Geological
Jiangfeng Liu, Hongyang Ni, Jianfu Shao, Xiaozhao Li, Yi Hong
Summary: The variation in gas permeability of unsaturated GMZ bentonite under coupled thermo-mechanical effects was investigated. The results show that temperature and confining pressure significantly affect gas permeability, and the extent of change is related to initial relative humidity conditions. Real-time water loss observation reflects that the gas migration process carries water vapor out as temperature increases, which leads to the sudden change in gas permeability.
ENGINEERING GEOLOGY
(2023)
Article
Engineering, Mechanical
J. Zhang, W. Y. Liu, Q. Z. Zhu, J. F. Shao
Summary: In this work, a novel constitutive model is developed to describe the mechanical behavior of rock-like materials under cyclic loading. The model incorporates the fatigue damage related to micro-structural degradation, creep deformation, and plastic deformation. The proposed model accurately captures the mechanical responses of different rocks under both monotonic and cyclic loading conditions.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Geological
Shi-Fan Liu, Wei Wang, Ya-Jun Cao, Hai-Feng Li, Jian-Fu Shao
Summary: This work presents a modified framework of the phase-field model coupled with plasticity to investigate the effect of loading rates on the fracture mechanism in elastoplastic rock-like materials. The damage-plasticity coupling effects on mechanical responses and failure modes are studied using an optimized pressure-sensitive plasticity model. The capability and accuracy of the proposed phase-field approach in capturing nonlocal damage evolution are validated based on analytical solutions for elastic/inelastic homogeneous cases. Numerical examples demonstrate the mixed-mode cracking behavior under quasi-static and dynamic loading conditions with various loading rates, capturing failure modes, dynamic damage profiles, and crack propagation velocities.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Engineering, Geological
Lu Ren, Lun-Yang Zhao, Fu-Jun Niu, Yuan-Ming Lai, Jian-Fu Shao
Summary: This paper aims to develop a nonlinear constitutive model that incorporates the effect of crack closure in order to capture the entire process of rock deformation and failure behavior under compression. The model is based on irreversible thermodynamics and considers the decomposition of total strain into crack closure strain, elastic strain, and plastic strain. New criteria are proposed for describing crack closure strain and plastic strain evolution. Analytical solutions for the model under conventional triaxial compression loading conditions are derived, and a robust semi-implicit return mapping algorithm is developed for practical applications. The model is validated against experimental data and found to accurately describe the nonlinear mechanical behaviors of rocks, including crack closure effect, strain hardening/softening, peak strength, residual strength, and compaction/dilation transition. A nonlocal formulation is also introduced to address mesh dependency issues.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Geological
Jing Xue, Yajun Cao, Nicolas Burlion, Jianfu Shao
Summary: This study investigates the influence of the interface transition zone (ITZ) on the elastic properties of concrete and rock like heterogeneous materials. Direct simulations of a representative volume element are performed using a fast Fourier transform based method to obtain reference solutions. Analytical homogenization models commonly used are evaluated by comparing them with the reference solutions. Based on this evaluation, an artificial neural network (ANN) model is developed to improve the analytical models. The proposed ANN model is trained, tested, and validated against the reference solution, demonstrating its efficiency and accuracy.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Mechanical
Lun-Yang Zhao, Zhao-Min Lv, Yuan-Ming Lai, Qi-Zhi Zhu, Jian-Fu Shao
Summary: In this paper, a new micromechanical damage model is presented for capturing the mechanical behaviors of quasi-brittle geomaterials. The model takes into account two essential coupled non-linear mechanisms: plastic deformation related to frictional sliding along microcrack surfaces, and microscopic damage induced by microcrack initiation and propagation. The main novelty lies in a new physically based friction law that captures plastic distortion, where the friction coefficient is a state-dependent variable. The model is validated through comparisons with experimental data and previous results.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Geological
H. L. Shi, T. Rougelot, S. Y. Xie, J. F. Shao, J. Talandier
Summary: The objective of this study is to investigate the deformation behavior of anisotropic claystone in relation to material heterogeneity. Five triaxial compression tests were conducted on Callovo-Oxfordian claystone samples under in-situ X-ray micro-tomography monitoring. Complete 3D images of the samples' full loading history were analyzed, and non-uniform strain fields were determined. The study focused on the effects of bedding planes, initial cracks, and confining stress on strain fields, and found that the structural anisotropy and confining pressure have a strong influence on strain distribution and cracking process.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Hai -Ling Shi, Thomas Rougelot, Shou-Yi Xie, Jian-Fu Shao, Minh-Ngoc Vu, Jean Talandier
Summary: The influences of resaturation processes in claystone were investigated using X-ray microtomography and Digital Volume Correlation. The results indicate that these processes have a significant impact on the mechanical properties of claystone at the sample scale.
Article
Materials Science, Multidisciplinary
Jing Xue, Yajun Cao, Jianfu Shao, Nicolas Burlion
Summary: This paper focuses on estimating the macroscopic elastic properties of composites with inclusions and pores. It compares analytical homogenization models with reference numerical results obtained from direct simulations, highlighting their weaknesses. A large dataset is then constructed using numerical results from Fast Fourier Transform simulations for various microstructures and elastic properties. An artificial neural network model with two hidden layers is trained using this dataset. Different validation tests show that the ANN-based model accurately estimates macroscopic elastic properties for strongly heterogeneous materials with different microstructures, porosities, and inclusion volume fractions.
MECHANICS OF MATERIALS
(2023)
Article
Mechanics
Jueliang Chen, Franck Agostini, Wanqing Shen, Jianfu Shao, Xavier Bourbon, Siyu Liu
Summary: In this study, an experimental investigation is conducted to evaluate the mechanical response and damage process in a typical reinforced concrete component with inserted steel discs. A numerical approach is developed based on the experimental data, which includes a homogenization scheme for estimating the elastic properties of corroded steel and a phase-field method to describe the evolution of corrosion-induced damage. The predicted values of reaction force are compared with experimental data, and the extent of damage and damaged zone are evaluated based on the corrosion-related expansion ratio.
MECHANICS RESEARCH COMMUNICATIONS
(2023)
Article
Engineering, Mechanical
Yue Sun, Emmanuel Roubin, Jianfu Shao, Jean-Baptiste Colliat
Summary: This study aims to simulate crack extension and investigate the influence of spatial heterogeneity distribution using an enhanced finite element method. The simulation captures various crack patterns and shows good consistency with experimental observations.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Geological
Yudan Jin, Meng Wang, Hailing Shi, Yun Jia, Qier Wu, Nicolas Burlion, Jianfu Shao
Summary: This study investigates the effect of inclusion size on drying shrinkage cracking in cementitious materials. A series of laboratory desiccation tests on concrete with different size of inclusions are conducted. Nondestructive X-ray micro-tomography images were used to reconstruct the drying-induced shrinkage cracks of samples in desiccation tests. To better understand the mechanism of shrinkage cracking, a fully coupled hydro-mechanical bond-based Peridynamic model was developed that takes into account the interactions among deformation, cracking, and permeability evolution. The efficiency of the proposed model was verified through two benchmark problems. The influence of inclusion size on shrinkage cracks was numerically analyzed by reproducing experimental results and conducting a parametric study. The results indicate that, as the size of the inclusion increases, the quantity of drying induced cracks increases while the length of the cracks decreases and the average width of the cracks increases. However, the distribution of cracks appears to be unaffected by the size of the inclusion.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Engineering, Civil
Jie Liu, Hualin Zhang, Hanbing Bian, Wei Wen, Ling Zeng
Summary: This study investigates the mechanical characteristics and cracking mechanism of fractured silty mudstone using a comprehensive approach. The results show that the dip angle and number of fractures have an impact on the peak strength, and the failure morphology can be categorized into tensile failure, shear failure, and tensile-shear combined failure.
KSCE JOURNAL OF CIVIL ENGINEERING
(2023)
