Article
Materials Science, Multidisciplinary
Babak Ravaji, Showren Datta, Caleb Foster, Jeffrey T. Lloyd, Justin W. Wilkerson, Shailendra P. Joshi
Summary: This study investigates the role of strain rate, texture, and stress state in the macro-micro mechanical characteristics of magnesium alloys. Simulations reveal a transition of the tensile response from conventional power-law type to sigmoidal type for certain combinations of textures, stress triaxiality levels, and strain rates. The stress response is strongly rate-dependent, while the macroscopic deformation anisotropy has negligible effect from strain rate compared to the stress state and texture.
MECHANICS OF MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Sai-Sai Guo, Jian-Guo Gong, Peng Zhao, Tian -Ye Niu, Fu-Zhen Xuan
Summary: This study investigates the time-dependent microstructural evolution and its dependence on stress state in 9-12% Cr steel notched components through creep tests with different root radii. The results show that during the transient stage, there is a significant redistribution of stress state, which affects the nucleation or growth of cavity. Precipitate coarsening is heterogeneous and promoted by high equivalent stress or stress triaxiality. In the steady stage, the magnitude of stress state influences the creep damage behavior, with higher cavity density and greater reduction in hardness observed in regions with high equivalent stress and stress triaxiality.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2023)
Article
Chemistry, Physical
Vladimir V. V. Skripnyak, Kristina V. Iohim, Vladimir A. A. Skripnyak
Summary: In this paper, the deformation and fracture of Ti-5Al-2.5Sn alloys were studied using the punch test at moderate strain rates. A micromechanical damage model coupled with a viscoplastic constitutive model was employed to describe the plastic flow and fracture behavior. Numerical simulations were carried out to validate the used constitutive relations, and the results showed good agreement with experimental data. The dynamic punch test was found to be suitable for evaluating damage kinetics under complex stress states.
Article
Engineering, Mechanical
Concetta Pelligra, Javad Samei, Jidong Kang, David S. Wilkinson
Summary: This study investigates the microstrain partitioning and damage evolution in vanadium-added and vanadium-free ultra-fine grained dual phase steels. The results show that vanadium microalloying enhances microstrain homogenization between ferrite and martensite and reduces strain gradients at the ferrite/martensite interfaces.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Vladimir V. Skripnyak, Vladimir A. Skripnyak
Summary: This paper presents the experimental results of the mechanical behavior of Ti-5Al-2.5Sn alloy at high strain rates and elevated temperature. The study found that the ductility of Ti-5Al-2.5Sn alloy increases with the increasing strain rate at elevated temperature.
Article
Materials Science, Multidisciplinary
Vladimir V. Skripnyak, Vladimir A. Skripnyak
Summary: By conducting tensile tests and Digital Image Correlation analysis, the mechanical behavior of the Ti-6Al-4V alloy at different strain rates was studied. It was found that at high strain rates, the alloy exhibited localized shear bands and the ultimate strain to fracture in the strain localization zone tended to increase with the strain rate, while showing a tendency towards embrittlement at high stress triaxialities.
Article
Engineering, Multidisciplinary
R. Nikhil, S. A. Krishnan, G. Sasikala, A. Moitra, Shaju K. Albert, A. K. Bhaduri
Summary: The study investigates the transferability of continuum damage parameters for ductile fracture of 316LN stainless steel from CT specimen to pipes. Through XFEM crack growth simulations, the applicability of damage parameters for different crack geometries in pipes was verified. Results showed that the crack initiation stress and crack evolution energy parameters established for 316LN SS were applicable for predicting crack growth behavior in pipes as well.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2021)
Article
Materials Science, Multidisciplinary
Tongzhou Gao, Yang Tong, Zhixin Zhan, Weiwei Mei, Weiping Hu, Qingchun Meng
Summary: A non-local approach is developed in this study to predict the fatigue life of notched specimens, taking into account stress/strain gradient and elastic-plastic fatigue damage. The mechanical behavior of the material is modeled using damage coupled constitutive models. Numerical simulations are conducted to compute the damage evolution process and predict fatigue life, while considering the coupling effects between stress field and damage field.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2022)
Article
Mechanics
V. V. Skripnyak
Summary: This study investigated the influence of stress triaxiality on the mechanical behavior of commercially pure titanium. Tensile tests were conducted at various strain rates and multiple analysis methods were used. The results showed that commercially pure titanium exhibits ductile behavior under certain conditions, and stress triaxiality affects the roughness of fracture surfaces.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Lian Song, Genfeng Li, Cong Zhu, Huaqiang Fang, Guoqing Zhu
Summary: This study investigates the ductile fracture of Q345 steel welded joint, establishes the constitutive model and fracture criterion model, and provides experimental parameters for the mechanical properties and fracture models of welded joints in structural engineering. These findings contribute to refined finite element models and the evaluation and design of building structures.
Article
Materials Science, Multidisciplinary
Miguel Ruiz de Sotto, Veronique Doquet, Patrice Longere, Jessica Papasidero
Summary: In this study, an extensive experimental campaign and numerical simulations were conducted to investigate the ductile fracture behavior of Ti-6Al-4V titanium alloy. The results showed that ductility of the material exhibited anisotropic characteristics depending on the stress state and strain rate, with different behavior observed in tension and compression. The fracture strain was found to decrease with increasing absolute value of the triaxiality, reaching a maximum close to zero, while no clear correlation with the Lode parameter was identified.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
Daniel Franzen, Niloufar Habibi, Markus Koenemann, Sebastian Muenstermann, Andreas Buehrig-Polaczek
Summary: An efficient assessment of the mechanical properties of ductile iron (DI) under dynamic loading is usually missing. To address this gap, a plasticity model for DI grade EN-GJS-500-14 was suggested. Fracture mechanics (FM) and Charpy impact (CI) tests, high-speed and impact tensile tests as well as tensile tests at variable temperature and stress states were carried out on DIs with silicon contents from 2.10 to 3.64 wt-%. Toughness-related results indicate a difference in the transition temperatures of 100-140 K between CI and FM tests. The reason for this is assumed to be a pronounced strain rate sensitivity, which could be confirmed in the study. The plasticity model was able to predict toughness properties in CI tests.
MATERIALS SCIENCE AND TECHNOLOGY
(2023)
Article
Nuclear Science & Technology
Jun-Min Seo, Hune-Tae Kim, Yun-Jae Kim, Hiroyuki Yamada, Tomohisa Kumagai, Hayato Tokunaga, Naoki Miura
Summary: In this paper, the effect of stress triaxiality and strain rate on fracture strain of austenitic stainless steel 304 was investigated through smooth and notched bar tensile tests. Test data revealed a decrease in true fracture strain with increasing stress triaxiality and strain rate. The Johnson-Cook (J-C) fracture strain model was employed to quantify the test data, providing a conservative prediction of true fracture strain with a difference of less than 20%. The conservatism in the strain-based acceptance criteria in ASME B&PV Code, Section III, Appendix FF was also discussed.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Mechanics
Hao Zhang, Xunpeng Li, Tao Gao, Haipeng Song, Ganyun Huang
Summary: The study experimentally investigates the deformation and fracture behaviors of pure titanium sheet specimens under different stress triaxialities, with strain localization leading to crack formation. Quantitative identification of the characteristics of the localized region is achieved through strain distribution analysis.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
Meiduo Chen, Songlin Xu, Liangzhu Yuan, Chunhe Miao, Jianhua Lu, Hao Ma, Guangfa Gao, Pengfei Wang
Summary: This study investigates the strain rate sensitivity and stress state effects on the mechanical behavior of concrete under dynamic load. Through true triaxial Hopkinson tests, the strain rate effect and intermediate principal stress effect of concrete are studied, along with the influence of heterogeneity. The experiments show that the triaxial data align well with the dynamic M-C strength, while the biaxial data deviates significantly from it, indicating the presence of an intermediate principal stress effect.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
E. Legostaeva, Yu P. Sharkeev, A. Yu Eroshenko, O. A. Belyavskaya, V. P. Vavilov, V. A. Skrypnyak, A. M. Ustinov, A. A. Klopotov, A. O. Chulkov, A. A. Kozulin, P. Uvarkin, V. V. Skrypnyak
Summary: The study found that there is a correlation between the average size of the structural elements in Zr-1 wt.% Nb alloy and its physico-mechanical properties and deformation characteristics, which can be described by linear functions.
Article
Physics, Multidisciplinary
E. V. Legostaeva, Yu. P. Sharkeev, O. A. Belyavskaya, V. P. Vavilov, V. A. Skripnyak, A. Yu. Zhilyakov, V. P. Kuznetsov, A. Yu. Eroshenko
Summary: The study investigated the thermal conductivity and specific heat capacity of Zr-1 wt.% Nb and Ti-45 wt.% Nb alloys in both coarse-grained and ultrafine-grained states. The results showed that the ultrafine-grained structure had a significant impact on the thermophysical properties of the alloys, affecting their energy dissipation and accumulation during deformation.
RUSSIAN PHYSICS JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
V. V. Skripnyak, K. Iohim, E. G. Skripnyak, V. A. Skripnyak
Summary: The study investigates the mechanical behavior of titanium alloy Ti-6Al-4V at different strain rates, revealing the presence of localized shear bands at high strain rates with significantly higher plastic strain. Additionally, the value of strain before fracture was found to increase with tension strain rate.
LETTERS ON MATERIALS
(2021)
Article
Physics, Multidisciplinary
A. Potekaev, G. N. Parvatov, V. V. Skripnyak, V. A. Skripnyak
Summary: This study investigates the physical and mechanical behavior of ice using numerical simulation and a damaged medium computational model, focusing on deformation and fracture under dynamic loading. By utilizing the Johnson-Holmquist (JH2) damage model and calibrating with experimental data, the model shows both qualitative and quantitative agreement with the behavior of Ih ice under dynamic loads, allowing for predictions of ice behavior under different conditions.
RUSSIAN PHYSICS JOURNAL
(2021)
Article
Physics, Applied
V. V. Skripnyak, V. A. Skripnyak
Summary: The article presents new results of numerical simulation on the mechanical behavior of metals and alloys with a hexagonal close-packed (HCP) lattice under dynamic loadings in a wide range of temperatures. A model for numerical simulation and a kinetic damage model were proposed to improve the accuracy of predicting dynamic fracture.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Vladimir V. Skripnyak, Vladimir A. Skripnyak
Summary: This paper presents the experimental results of the mechanical behavior of Ti-5Al-2.5Sn alloy at high strain rates and elevated temperature. The study found that the ductility of Ti-5Al-2.5Sn alloy increases with the increasing strain rate at elevated temperature.
Article
Chemistry, Physical
Elena Legostaeva, Anna Eroshenko, Vladimir A. Vavilov, Vladimir Skripnyak, Arsenii Chulkov, Alexander V. Kozulin, Ivan Glukhov, Yurii Sharkeev
Summary: A comprehensive study on the deformation and temperature behavior, as well as the energy accumulation and dissipation during plastic deformation, was conducted. Microstructural analysis revealed changes in the energy dissipation and accumulation patterns of pure titanium and Ti-45Nb alloy samples in different grain states. The structural transformation features during deformation were also explored, providing insights into the local softening mechanism before fracture.
Article
Chemistry, Physical
Vladimir V. V. Skripnyak, Kristina V. Iohim, Vladimir A. A. Skripnyak
Summary: In this paper, the deformation and fracture of Ti-5Al-2.5Sn alloys were studied using the punch test at moderate strain rates. A micromechanical damage model coupled with a viscoplastic constitutive model was employed to describe the plastic flow and fracture behavior. Numerical simulations were carried out to validate the used constitutive relations, and the results showed good agreement with experimental data. The dynamic punch test was found to be suitable for evaluating damage kinetics under complex stress states.
Article
Materials Science, Multidisciplinary
Elena Legostaeva, Anna Eroshenko, Vladimir A. Vavilov, Vladimir Skripnyak, Nikita Luginin, Arsenii Chulkov, Alexander V. Kozulin, Juergen Schmidt, Alexey Tolmachev, Pavel Uvarkin, Yurii Sharkeev
Summary: The microstructural investigation, mechanical properties, and energy accumulation and dissipation of the magnesium alloy Mg-2.9Y-1.3Nd were studied in the recrystallized state and after severe plastic deformation (SPD) by extrusion. The use of SPD resulted in the formation of a bimodal structure, increased yield strength, tensile strength, and plasticity, and caused substructural hardening, phase composition redistribution, and texture formation. SPD also led to a redistribution of thermal energy and reduced the strain hardening coefficient.
Article
Mechanics
Vladimir V. Skripnyak, Kristina Iokhim, Vladimir A. Skripnyak
Summary: The study examines the effect of a triaxial stress state on the mechanical behavior and fracture of commercially pure titanium at various strain rates. Results indicate a nonmonotonic impact of strain rate on ultimate deformation before fracture, with shear bands occurring at higher strain rates. Under certain conditions, commercially pure titanium exhibits ductile behavior in fractures.
VESTNIK TOMSKOGO GOSUDARSTVENNOGO UNIVERSITETA-MATEMATIKA I MEKHANIKA-TOMSK STATE UNIVERSITY JOURNAL OF MATHEMATICS AND MECHANICS
(2021)
Article
Engineering, Mechanical
Vladimir A. Skripnyak, Kristina Iokhim, Evgeniya Skripnyak, Vladimir V. Skripnyak
Summary: This study analyzed the plastic flow of titanium alloys during the Linear Friction Welding (LFW) process through numerical simulations. A new coupling thermomechanical 3D model for joining structural elements from different types of titanium alloys was proposed, showing that the formation of welded joints occurs in a complex stress-strain state.
FACTA UNIVERSITATIS-SERIES MECHANICAL ENGINEERING
(2021)
