Three-dimensional effects on cracked discs and plates under nominal Mode III loading
The existence of three-dimensional effects at cracks has been known for many years, but understanding has been limited, and for some situations still is. Understanding improved when the existence of corner point singularities and their implications became known. Increasingly powerful computers mad...
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Gruppo Italiano Frattura
2015-10-01
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| Series: | Fracture and Structural Integrity |
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| Online Access: | http://www.gruppofrattura.it/pdf/rivista/numero34/numero_34_art_20.pdf |
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| author | A. Campagnolo F. Berto L. P. Pook |
| author_facet | A. Campagnolo F. Berto L. P. Pook |
| author_sort | A. Campagnolo |
| collection | DOAJ |
| description | The existence of three-dimensional effects at cracks has been known for many years, but
understanding has been limited, and for some situations still is. Understanding improved when the existence of
corner point singularities and their implications became known. Increasingly powerful computers made it
possible to investigate three-dimensional effects numerically in detail. Despite increased understanding, threedimensional
effects are sometimes ignored in situations where they may be important. The purpose of the
present contribution is to review the study carried out by the same authors in some recent investigations, in
which a coupled fracture mode generated by anti-plane loading of a straight through-the-thickness crack in
linear elastic discs and plates has been analysed by means of accurate 3D finite element (FE) models.
The results obtained from the highly accurate finite element analyses have improved understanding of the
behaviour of through cracked components under anti-plane loading. The influence of plate bending is
increasingly important as the thickness decreases. It appears that a new field parameter, probably a singularity, is
needed to describe the stresses at the free surfaces. Discussion on whether KIII tends to zero or infinity as a
corner point is approached is futile because KIII is meaningless at a corner point.
The intensity of the local stress and strain state through the thickness of the cracked components has been
evaluated by using the strain energy density (SED) averaged over a control volume embracing the crack tip. The
SED has been considered as a parameter able to control fracture in some previous contributions and can easily
take into account also coupled three-dimensional effects. Calculation of the SED shows that the position of the
maximum SED in the discs case is a function of the thickness. In the plates case instead the position of the
maximum SED is independent of plate thickness, contrary to disc results. |
| format | Article |
| id | doaj-art-c36c8b0642fd4b3cbfe88cb6429a97cd |
| institution | Kabale University |
| issn | 1971-8993 1971-8993 |
| language | English |
| publishDate | 2015-10-01 |
| publisher | Gruppo Italiano Frattura |
| record_format | Article |
| series | Fracture and Structural Integrity |
| spelling | doaj-art-c36c8b0642fd4b3cbfe88cb6429a97cd2025-01-02T23:02:13ZengGruppo Italiano FratturaFracture and Structural Integrity1971-89931971-89932015-10-0193419019910.3221/IGF-ESIS.34.20Three-dimensional effects on cracked discs and plates under nominal Mode III loadingA. Campagnolo0F. Berto1L. P. Pook2University of Padova,ItalyUniversity of Padova,Italy21 Woodside Road, Sevenoaks TN13 3HF (United Kingdom)The existence of three-dimensional effects at cracks has been known for many years, but understanding has been limited, and for some situations still is. Understanding improved when the existence of corner point singularities and their implications became known. Increasingly powerful computers made it possible to investigate three-dimensional effects numerically in detail. Despite increased understanding, threedimensional effects are sometimes ignored in situations where they may be important. The purpose of the present contribution is to review the study carried out by the same authors in some recent investigations, in which a coupled fracture mode generated by anti-plane loading of a straight through-the-thickness crack in linear elastic discs and plates has been analysed by means of accurate 3D finite element (FE) models. The results obtained from the highly accurate finite element analyses have improved understanding of the behaviour of through cracked components under anti-plane loading. The influence of plate bending is increasingly important as the thickness decreases. It appears that a new field parameter, probably a singularity, is needed to describe the stresses at the free surfaces. Discussion on whether KIII tends to zero or infinity as a corner point is approached is futile because KIII is meaningless at a corner point. The intensity of the local stress and strain state through the thickness of the cracked components has been evaluated by using the strain energy density (SED) averaged over a control volume embracing the crack tip. The SED has been considered as a parameter able to control fracture in some previous contributions and can easily take into account also coupled three-dimensional effects. Calculation of the SED shows that the position of the maximum SED in the discs case is a function of the thickness. In the plates case instead the position of the maximum SED is independent of plate thickness, contrary to disc results.http://www.gruppofrattura.it/pdf/rivista/numero34/numero_34_art_20.pdfFracture mechanicsFinite element analysisAnti-plane loadingStress intensity factorCorner point effects. |
| spellingShingle | A. Campagnolo F. Berto L. P. Pook Three-dimensional effects on cracked discs and plates under nominal Mode III loading Fracture and Structural Integrity Fracture mechanics Finite element analysis Anti-plane loading Stress intensity factor Corner point effects. |
| title | Three-dimensional effects on cracked discs and plates under nominal Mode III loading |
| title_full | Three-dimensional effects on cracked discs and plates under nominal Mode III loading |
| title_fullStr | Three-dimensional effects on cracked discs and plates under nominal Mode III loading |
| title_full_unstemmed | Three-dimensional effects on cracked discs and plates under nominal Mode III loading |
| title_short | Three-dimensional effects on cracked discs and plates under nominal Mode III loading |
| title_sort | three dimensional effects on cracked discs and plates under nominal mode iii loading |
| topic | Fracture mechanics Finite element analysis Anti-plane loading Stress intensity factor Corner point effects. |
| url | http://www.gruppofrattura.it/pdf/rivista/numero34/numero_34_art_20.pdf |
| work_keys_str_mv | AT acampagnolo threedimensionaleffectsoncrackeddiscsandplatesundernominalmodeiiiloading AT fberto threedimensionaleffectsoncrackeddiscsandplatesundernominalmodeiiiloading AT lppook threedimensionaleffectsoncrackeddiscsandplatesundernominalmodeiiiloading |