Article
Construction & Building Technology
Qun He, Michael C. H. Yam, Zhiyang Xie, Xue-Mei Lin, Kwok-Fai Chung
Summary: In this study, it is shown that the classical J2 flow theory is inappropriate for describing the plastic behavior of structural steels under different stress states. A numerical framework is proposed to characterize the strain hardening and ductile fracture initiation considering the effect of stress states. The validity of the proposed model is verified through single element tests and existing test results.
STEEL AND COMPOSITE STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Jiamin Sun, Klaus Dilger
Summary: A study on the accurate prediction of welding residual stresses (WRS) in ultra-high strength steel S960 weldments found that the amount of strain hardening for S960 steel is low at room and high temperatures, but non-ignorable at medium temperatures. The applied material plasticity model had almost no influence on the computed longitudinal residual stress, but could slightly affect the predicted magnitude of transverse residual stress. The use of a perfect-plastic (non-hardening) model is recommended for accurately predicting WRS in numerical simulation of S960 steel.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Mechanics
Jin-Ha Hwang, Yun-Jae Kim, Jin-Weon Kim, Sang-Eon Kim
Summary: A new cyclic hardening model is proposed based on combined experimental and numerical analyses to simulate the deformation of a cracked structure under large amplitude cyclic loading. The model results agreed well with the experimental displacement data, while also examining the effects of hardening in the first loading cycle on the subsequent cycles.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Kamran M. A. Iqbal
Summary: This study proposes a modified HJC model to simulate the behavior of concrete under large strains, high strain rate, and high pressure. The modified model includes various damage models to reproduce the crushing, spalling, scabbing, and radial cracking in concrete. The Lode-Angle model and strain rate effect are also incorporated to account for the difference in shear strength and to accurately model the dynamic strengths. The proposed model (MHJC_K & I) demonstrates better accuracy and performance compared to the existing models.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Construction & Building Technology
Yu Rong, Huilan Ren, Xiangzhao Xu
Summary: This paper presents an improved damage-plasticity material model for concrete to predict its mechanical response under dynamic loading. The model modifies the failure strength surface based on the current extent of damage and separately defines shear, compacted, and tensile damage. It introduces a unified hardening/softening function to predict strain hardening and softening behaviors under compression, taking into consideration the Lode angle effect and strain rate effect. The feasibility and accuracy of this improved concrete model are verified through experiments and numerical simulations.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Engineering, Mechanical
F. H. Wang, H. Qiao, Y. Q. Wang, J. Dong, Y. Y. Jiang, P. D. Wu
Summary: The study utilized the EVPSC-TDT model to simulate the stabilized stress-strain hysteresis loops of rolled AZ31B plate in different material orientations under cyclic loading, showing good agreement with experimental data. Parameters influencing plastic response were investigated and the effect of initial CRSS on twinning and detwinning during reverse loading was studied. The discrepancies between simulations and experiments suggest the need for further investigation into microstructure-related properties and internal tensile stresses of twinned grains.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Engineering, Mechanical
E. Madenci, A. Barut, A. Yaghoobi, N. Phan, R. S. Fertig
Summary: This study introduces a fatigue model for constant and variable amplitude cyclic loading by combining KTF with PD, demonstrating the reliability of this model through simulations of composite laminates with open-hole defects under cyclic loads.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Zhichao Wei, Steffen Gerke, Michael Bruenig
Summary: This paper introduces a modified anisotropic stress-state-dependent plastic-damage continuum model to predict the plastic, damage, and fracture behavior of metals under different loading conditions. Experimental and numerical validations are performed to verify the effectiveness of the model, using techniques such as digital image correlation and scanning electron microscopy.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Engineering, Environmental
Roohollah Shirani Faradonbeh, Abbas Taheri, Murat Karakus
Summary: Cyclic loading-induced hazards pose severe instability problems for surface and underground geotechnical projects. This study proposed an innovative double-criteria damage-controlled testing method to understand rock failure mechanisms under cyclic loading. The results showed slight increase in strength of rock specimens with increase in fatigue life in the pre-peak region due to cyclic loading-induced hardening, and a combination of class I and class II behaviors in the post-peak region during cyclic loading tests.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Chemistry, Physical
Rama K. Sabat, Waqas Muhammad, Raja K. Mishra, Kaan Inal
Summary: The microstructure and texture evolution of 6063 aluminum alloys under T4 and T6 conditions during cyclic shear tests were investigated. The results showed that the T6 sample had a higher rate of KAM value increase and slightly greater texture rotation compared to the T4 sample. Latent hardening was mainly attributed to dislocation-dislocation interactions and differences in precipitate volume fractions. The mechanical properties exhibited complex changes, with more significant variations observed in the T6 sample.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
Kai-Shang Li, Ji Wang, Zhi-Chao Fan, Lv-Yi Cheng, Shu-Lei Yao, Run-Zi Wang, Xian-Cheng Zhang, Shan-Tung Tu
Summary: This study proposes an energy-based model to predict the creep-fatigue combined with high-low cyclic loading (CF-HL) life, taking into account the interactions between different damage modes. Experimental results validate the prediction capabilities of the model, and a new assessment method based on a three-dimensional damage interaction diagram is proposed.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
C. A. Bronkhorst, H. Cho, P. W. Marcy, S. A. Vander Wiel, S. Gupta, D. Versino, V. Anghel, G. T. Gray
Summary: Accurately representing porosity-based ductile damage in polycrystalline metallic materials remains a significant challenge, but a soft-coupled linkage technique between a macro-scale damage model and micro-mechanical calculations has shown promise in this study. The micro mechanical model captures non-Schmid effects and suggests significant influences on local stress conditions across grain boundaries and triple junctions within the polycrystalline network.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
Xiancai Zhang, Hu Huang, Po Li
Summary: Based on large dynamic triaxial tests, a dynamic damage model for CSG material was established to study the relationship between damage variables and cycle number under cyclic loading. The model shows an inverted S-shaped curve with three stages corresponding to original defect closure, crack initiation and propagation, and unstable propagation, which can determine the fatigue life of CSG material.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Engineering, Geological
Juntao Ma, Guoxin Wang, Pengjie Lu
Summary: A new method based on fiber-beam element damage in section is proposed to evaluate the residual bending bearing capacity of damaged RC columns under cyclic loading. Quantitative indexes FDI and SDI are suggested to determine weak section of RC columns, describe section damage status, and calculate RBC. Experimental verification shows that the new method can accurately assess the performance of members under cyclic loading.
BULLETIN OF EARTHQUAKE ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Jiamin Sun, Thomas Nitschke-Pagel, Klaus Dilger
Summary: The objective of this research is to systematically investigate the impact of strain-hardening models and phase- and temperature-dependent strain-hardening slopes on computed residual stresses in welded joints. The study found that the material plasticity model significantly affects the predicted welding residual stresses. The results also showed that the isotropic hardening model accurately predicts the residual stresses in S235 steel, while the temperature-dependent strain-hardening slopes of the generated phases have minimal impact.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Shuozhi Xu, Jaber R. Mianroodi, Abigail Hunter, Bob Svendsen, Irene J. Beyerlein
INTERNATIONAL JOURNAL OF PLASTICITY
(2020)
Article
Multidisciplinary Sciences
Bob Svendsen
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2020)
Article
Multidisciplinary Sciences
Atefeh Alipour, Stefanie Reese, Bob Svendsen, Stephan Wulfinghoff
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2020)
Article
Chemistry, Physical
Jaber Rezaei Mianroodi, Bob Svendsen
Article
Engineering, Multidisciplinary
P. Shanthraj, C. Liu, A. Akbarian, B. Svendsen, D. Raabe
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Engineering, Multidisciplinary
Christian Gierden, Julian Kochmann, Johanna Waimann, Tobias Kinner-Becker, Jens Soelter, Bob Svendsen, Stefanie Reese
Summary: The work aims to develop an efficient two-scale numerical scheme for predicting the mechanical behavior of polycrystalline materials at finite strains, based on the relationship between macroscopic constitutive behavior and microstructural deformations. By solving two locally coupled boundary value problems, complex macroscopic problems can be simulated in a two-scale manner efficiently.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Chemistry, Physical
Jaber Rezaei Mianroodi, Pratheek Shanthraj, Bob Svendsen, Dierk Raabe
Summary: The current work utilizes Microscopic Phase-Field Chemomechanics to model solute segregation, dislocation-solute interaction, spinodal decomposition, and precipitate formation at straight dislocations and boundaries, exploring the effects of different configurations.
Article
Multidisciplinary Sciences
X. Zhou, J. R. Mianroodi, A. Kwiatkowski da Silva, T. Koenig, G. B. Thompson, P. Shanthraj, D. Ponge, B. Gault, B. Svendsen, D. Raabe
Summary: Dislocations are one-dimensional defects in crystals that affect material deformation, mechanical response, and transport properties. They lead to severe lattice distortion and solute segregation, resulting in localized spatial variations in chemistry that determine microstructure and material behavior. Recent advances in atomic-scale characterization methods have revealed a wide variety of defect-specific solute decoration patterns, offering potential for compositional and structural nano-scale design of advanced materials.
Article
Engineering, Multidisciplinary
Christian Gierden, Johanna Waimann, Bob Svendsen, Stefanie Reese
Summary: This study presents a modified model order reduction technique for the FFT-based simulation of composite microstructures, utilizing sampling patterns adapted to the spatial arrangement of individual phases to improve accuracy and efficiency in microstructural results.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Yang Bai, Jaber Rezaei Mianroodi, Yan Ma, Alisson Kwiatkowski da Silva, Bob Svendsen, Dierk Raabe
Summary: This study developed a model that explores the interaction between phase transformation, chemical reaction, species diffusion, deformation, and microstructure evolution. The simulations revealed that elastic stress had a negative impact on phase transformations, but high elastic stress could accelerate the transformation and result in a higher reduction degree. The model successfully predicted the observed microstructure evolution in experiments and found that filled pores with water vapor could influence the local reaction atmosphere and dynamics.
Article
Materials Science, Multidisciplinary
Mohammad Sarkari Khorrami, Jaber Rezaei Mianroodi, Bob Svendsen
Summary: The purpose of this work is to develop and determine higher-order continuum-like measures for characterizing discrete kinematic data. The concept of discrete local deformation is introduced and utilized to characterize non-affine and incompatible displacement information. The approach is demonstrated and verified using examples based on non-affine and incompatible displacement information.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Review
Chemistry, Physical
Jaber Rezaei Mianroodi, Pratheek Shanthraj, Chuanlai Liu, Samad Vakili, Sharan Roongta, Nima Hamidi Siboni, Nathan Perchikov, Yang Bai, Bob Svendsen, Franz Roters, Dierk Raabe, Martin Diehl
Summary: This paper explores the complex interplay between chemistry, microstructure, and behavior of engineering materials, utilizing computational modeling methods such as continuum thermodynamics, phase-field methods, and crystal plasticity. These models facilitate the understanding of multiple physical mechanisms and their interactions during microstructure evolution.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Mohammad Sarkari Khorrami, Jaber Rezaei Mianroodi, Bob Svendsen
Summary: The purpose of this study is to develop a finite-deformation phase-field microelasticity theory and apply it to the modeling of dislocation core and dislocation interaction/reaction on intersecting glide planes in fcc crystals. The results show good agreement between the finite-deformation phase-field microelasticity and atomistic simulation results in terms of dislocation core and dislocation reactions.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Jaber Rezaei Mianroodi, Pratheek Shanthraj, Alisson Kwiatkowski da Silva, Bob Svendsen, Dierk Raabe
Summary: This study investigates the Mn enrichment at dislocations in Fe-Mn alloys through modeling and experimental characterization. Both finite-deformation microscopic phase-field chemomechanics (MPFCM) and Monte Carlo molecular dynamics (MCMD) are used. The results show that both MPFCM and MCMD predict a non-zero hydrostatic stress field in screw cores, and the amount of solute segregating to screw cores is much less than that to edge cores. The concentration dependence of the solute misfit distortion has the strongest effect, and the prediction of Mn concentration along a straight dislocation line by MPFCM differs from the experimental results.
Article
Chemistry, Physical
Mohammad S. Khorrami, Jaber R. Mianroodi, Nima H. Siboni, Pawan Goyal, Bob Svendsen, Peter Benner, Dierk Raabe
Summary: The purpose of this work is to develop a trained artificial neural network for surrogate modeling of the mechanical response of elasto-viscoplastic grain microstructures. A U-Net-based convolutional neural network (CNN) is trained using numerical solutions for the von Mises stress field from initial-boundary-value problems (IBVPs) for mechanical equilibrium in such microstructures subject to quasi-static uniaxial extension. The resulting trained CNN (tCNN) accurately reproduces the von Mises stress field about 500 times faster than numerical solutions based on spectral methods. The application of the tCNN to test cases not contained in the training dataset is also investigated and discussed.
NPJ COMPUTATIONAL MATERIALS
(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)
