Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens
Complete understanding of the local stress triaxiality and stress concentration is essential to ensuring structural safety of several structures. A combination of mechanical tests with numerical simulations can be used to obtain this information. One way to study stress triaxiality is by modifying t...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
2023-05-01
|
| Series: | Materials Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000200208&tlng=en |
| _version_ | 1797816853718892544 |
|---|---|
| author | Letícia dos Santos Pereira Gustavo Henrique Bolognesi Donato Miguel Mattar Neto |
| author_facet | Letícia dos Santos Pereira Gustavo Henrique Bolognesi Donato Miguel Mattar Neto |
| author_sort | Letícia dos Santos Pereira |
| collection | DOAJ |
| description | Complete understanding of the local stress triaxiality and stress concentration is essential to ensuring structural safety of several structures. A combination of mechanical tests with numerical simulations can be used to obtain this information. One way to study stress triaxiality is by modifying the standard tensile test geometry (ASTM E8) with a notch. Based on previous results from the literature, five notches were chosen: 10, 5, 3, 2, and 1 mm. These geometries were tested, and the results were numerically reproduced using the Abaqus/Explicit 2020 software. The models used were a non-linear model with the Gurson-Tvergaard-Needleman damage model to reproduce the failure. The numerical analyses allowed the assessment of the von Mises stress and stress triaxiality near the notch to compare with the standard smooth specimen. Two instants were considered as crack propagation onset; the instant of the maximum von Mises stress in the element at the center of the specimen, where the failure process begins; and the moment of maximum stress in the true stress x true strain curve. For the von Mises stress analysis, the difference between the curves was small. The stress triaxiality is a better variable to visualize the influences of the notch. When the strain is equal to a 0.07 (instant of the maximum force for the standard specimens), for the smaller notches (1 and 2 mm), there is a region where the effective plastic strain is zero. Consequently, the stress triaxiality is larger in this region than in the center. For the crack propagation onset instant, the plastic strain occurs along the whole transversal section. In this instant, the maximum value of stress triaxiality occurs in the center for all specimens. These results demonstrate that the stress triaxiality changes as the strain increases, i.e., varies with time. |
| first_indexed | 2024-03-13T08:43:50Z |
| format | Article |
| id | doaj.art-26641180a7764ff4881c7af20c2a99f7 |
| institution | Directory Open Access Journal |
| issn | 1516-1439 |
| language | English |
| last_indexed | 2024-03-13T08:43:50Z |
| publishDate | 2023-05-01 |
| publisher | Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) |
| record_format | Article |
| series | Materials Research |
| spelling | doaj.art-26641180a7764ff4881c7af20c2a99f72023-05-30T07:32:06ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392023-05-0126suppl 110.1590/1980-5373-mr-2022-0572Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile SpecimensLetícia dos Santos Pereirahttps://orcid.org/0000-0002-3169-002XGustavo Henrique Bolognesi Donatohttps://orcid.org/0000-0003-0807-8745Miguel Mattar NetoComplete understanding of the local stress triaxiality and stress concentration is essential to ensuring structural safety of several structures. A combination of mechanical tests with numerical simulations can be used to obtain this information. One way to study stress triaxiality is by modifying the standard tensile test geometry (ASTM E8) with a notch. Based on previous results from the literature, five notches were chosen: 10, 5, 3, 2, and 1 mm. These geometries were tested, and the results were numerically reproduced using the Abaqus/Explicit 2020 software. The models used were a non-linear model with the Gurson-Tvergaard-Needleman damage model to reproduce the failure. The numerical analyses allowed the assessment of the von Mises stress and stress triaxiality near the notch to compare with the standard smooth specimen. Two instants were considered as crack propagation onset; the instant of the maximum von Mises stress in the element at the center of the specimen, where the failure process begins; and the moment of maximum stress in the true stress x true strain curve. For the von Mises stress analysis, the difference between the curves was small. The stress triaxiality is a better variable to visualize the influences of the notch. When the strain is equal to a 0.07 (instant of the maximum force for the standard specimens), for the smaller notches (1 and 2 mm), there is a region where the effective plastic strain is zero. Consequently, the stress triaxiality is larger in this region than in the center. For the crack propagation onset instant, the plastic strain occurs along the whole transversal section. In this instant, the maximum value of stress triaxiality occurs in the center for all specimens. These results demonstrate that the stress triaxiality changes as the strain increases, i.e., varies with time.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000200208&tlng=enTensile teststress triaxialityvon Mises stressGTN modelnotch |
| spellingShingle | Letícia dos Santos Pereira Gustavo Henrique Bolognesi Donato Miguel Mattar Neto Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens Materials Research Tensile test stress triaxiality von Mises stress GTN model notch |
| title | Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens |
| title_full | Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens |
| title_fullStr | Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens |
| title_full_unstemmed | Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens |
| title_short | Assessment of the Von Mises Stresses and Stress Triaxiality in Notches Using Modified Tensile Specimens |
| title_sort | assessment of the von mises stresses and stress triaxiality in notches using modified tensile specimens |
| topic | Tensile test stress triaxiality von Mises stress GTN model notch |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392023000200208&tlng=en |
| work_keys_str_mv | AT leticiadossantospereira assessmentofthevonmisesstressesandstresstriaxialityinnotchesusingmodifiedtensilespecimens AT gustavohenriquebolognesidonato assessmentofthevonmisesstressesandstresstriaxialityinnotchesusingmodifiedtensilespecimens AT miguelmattarneto assessmentofthevonmisesstressesandstresstriaxialityinnotchesusingmodifiedtensilespecimens |