Article
Materials Science, Multidisciplinary
Michael Bruenig, Moritz Zistl, Steffen Gerke
Summary: Experimental studies show that the strength of ductile metals depends significantly on stress state and stress history, impacting the safety and lifetime of engineering structures. This paper focuses on the numerical analysis of load path influence on damage and fracture behavior of aluminum alloys, discussing a continuum damage model that considers stress state and loading history effects.
Article
Materials Science, Multidisciplinary
Nathan Spulak, Jeremy Seidt, Amos Gilat
Summary: The ductile fracture behavior of 2024 aluminum under unequal in-plane biaxial tension and out-of-plane compression is studied using a novel experimental design and numerical simulations. Fracture is observed directly during loading in unbacked specimens and using interrupted testing and acoustic emissions in tests with a backing plate. The plasticity model used in the simulations is validated by matching the simulated response with experimental data, and the equivalent plastic fracture strain is determined for various stress states.
MECHANICS OF MATERIALS
(2023)
Article
Engineering, Manufacturing
Rui Li, Zebang Zheng, Mei Zhan, Hongrui Zhang, Xiaolei Cui, Yudong Lei
Summary: The applicability of eight uncoupled ductile fracture criteria was systematically studied and their predictive capabilities were compared and analyzed through numerical simulation and experimental comparison under various stress states.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Materials Science, Multidisciplinary
Senad Razanica, Lennart B. Josefson, Ragnar Larsson, Torsten Sjogren
Summary: Fracture modeling and experimental validation of Compacted Graphite Iron (CGI) specimens loaded under quasi-static conditions at room temperature are considered. Continuum damage mechanics coupled to plasticity is adopted to describe the evolution of damage. It is shown from the testing and the simulations that plastic strains generally need to be accounted for in order to properly describe the different failure processes of the CGI specimens.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2021)
Article
Engineering, Mechanical
Lihuang Zheng, Zhongjin Wang, Bao Meng, Min Wan
Summary: A unified uncoupled ductile fracture criteria (DFC) that can accurately predict the fracture initiation of both sheet and bulk metals is proposed in this study. The new DFC takes into account multiple void deformation modes and the effects of accelerated void growth and coalescence under high stress triaxiality. Experimental results and comparative studies demonstrate the superiority of the new DFC over other existing DFCs. Due to its high accuracy and flexibility, the new DFC is recommended for use in engineering applications and integration with finite element analysis software.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Yigang Wang, Kaijie Wang, Tao Wang, Dongyang Chu, Zhanli Liu
Summary: This study characterized and analyzed the stress state dependence of the transition from strain localization to fracture of metal materials, and found that stress triaxiality plays a significant role in the transition process. A critical value of stress triaxiality was identified as the characteristic point of the brittle-ductile transition. This work is meaningful for evaluating the safety of metal structures under complex loads.
INTERNATIONAL JOURNAL OF FRACTURE
(2021)
Article
Mechanics
Zengli Peng, Haisheng Zhao, Xin Li, Lin Yuan, Tong Zhu
Summary: This study focuses on the ductile fracture behavior of X80 pipeline steel through experimental and numerical approaches. Nineteen experiments are conducted, including uniaxial tension, plain strain tension, pure shear, and shear plus tension/compression. Three fracture modes are observed, and a hybrid testing-FE method is used to determine the post-necking strain hardening curve. Ductile fracture parameters are obtained through parallel computations in Abaqus. The results show that a newly proposed model performs better than the other two calibrated models in terms of stability and accuracy for fracture prediction.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Multidisciplinary
Sina Abrari Vajari, Matthias Neuner, Prajwal Kammardi Arunachala, Andy Ziccarelli, Gregory Deierlein, Christian Linder
Summary: Phase field models for ductile fracture have been widely studied, but most existing methods only consider the effects of plastic deformation and neglect the multi-axial stress states in practical designs. In this work, a thermodynamically consistent phase field method coupled with finite strain plasticity is proposed to address this issue. The Stress-Weighted Ductile Fracture Model (SWDFM) is utilized to capture the coupling between plasticity and stress states. The excellent performance of the SWDFM in predicting ductile crack initiation motivates its incorporation into the phase field approach for predicting crack initiation and propagation.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Industrial
Takashi Matsuno, Kouta Nakagiri, Tomoko Matsuda, Toshiyuki Tanaka, Takashi Yasutomi, Hiroto Shoji, Mitsuru Ohata
Summary: This study identified the strain/stress range during shearing of conventional and improved AISI-D2 tool steels, and proposed ductile fracture design curves for evaluation. The results indicated the superiority of the improved AISI-D2 steel material, highlighting a drastically large fracture strain compared to high-pressure tensile tests.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Mechanics
Tamilselvan Nambirajan, P. C. Ashwin Kumar, Sahil Aggarwal, Abhishek Gurudutt
Summary: This study extracts 48 specimens from three structural steel grades used in the Indian construction industry and simulates the stress states of ductile fracture initiation. Through testing and numerical modeling, ductile fracture initiation parameters are extracted and a three-dimensional fracture locus is constructed. Additionally, a new ductile fracture model is proposed and compared with existing models, showing better prediction accuracy.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Industrial
Takashi Matsuno, Kouta Nakagiri, Tomoko Matsuda, Toshiyuki Tanaka, Takashi Yasutomi, Hiroto Shoji, Mitsuru Ohata
Summary: The deformation and fracture of tools during the shearing process of ultra-high-strength steel is a serious problem. This study used finite element simulations to evaluate improved tool edge designs and identified the strain/stress range for which no fracture occurs. The effectiveness of the proposed method was confirmed by demonstrating the superiority of the improved AISI-D2 steel material.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Physical
Felix Rickhey, Seokmoo Hong
Summary: This study investigates the crucial parameter of stress triaxiality (eta) in ductile damage prediction, particularly for anisotropic materials. It presents an alternative method to obtain eta directly from strains, and validates different yield criteria for predicting triaxiality. The findings have significant implications for damage prediction and design in materials.
Article
Engineering, Mechanical
Parmida Abedinimanesh, Faraz Hazinia, Mehdi Ganjiani
Summary: This study investigates the damage growth and fracture locus of specimens with plane anisotropy under different triaxiality. Damage evolution during deformation is achieved using the loading-unloading technique in tensile test. Different stress triaxiality is achieved by changing the geometry of the fracture zone in the simple tension specimen. Three different geometries of aluminum 1100 specimens, including dog-bone, notched, and in-plane shear specimens, were fabricated. The anisotropy behavior was investigated by testing all samples along rolling, diagonal, and transverse directions. The experimental results were validated using a combined experimental-numerical simulation in ABAQUS/Explicit. It was found that anisotropy has no significant effect on fracture strain and damage evolution for aluminum 1100, while stress triaxiality has a significant effect.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Zhao Zhang, Yanqing Wu, Fenglei Huang
Summary: Finite element analysis was conducted to investigate the impact of stress triaxiality cut-off value on the ballistic behavior of Al2024-T351 plates. Different nose shaped projectiles were used, and the plastic and fracture behavior of the plates were described by a modified Johnson-Cook model and the DF2021 criterion. The study aimed to evaluate the necessity of considering stress triaxiality cut-off value in predicting ballistic behavior through finite element simulations.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Mechanics
Thomas Beerli, Vincent Grolleau, Dirk Mohr, Christian C. Roth
Summary: A new axisymmetric V-bending technique is proposed to identify the strain to fracture for plane strain tension for the weakest in-plane direction of sheet metal. Experimental results show that the method is robust and exhibits low sensitivity to geometric imperfections. Experiments on different materials validate the proposed technique through comparison with conventional methods.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)