scholarly journals Geometry Effects on Mode I Brittle Fracture in VO-Notched PMMA Specimens

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 3017
Author(s):  
Robab Bahadori ◽  
Majid Reza Ayatollahi ◽  
Sergio Cicero ◽  
José Alberto Álvarez
Keyword(s):  
Tangential Stress ◽  
Fracture Strength ◽  
Experimental Tests ◽  
Fracture Initiation ◽  
Maximum Tangential Stress ◽  
Mode I ◽  
Pure Mode ◽  
Mode I Loading ◽  
Order Stress ◽  
Experimental Findings

This paper gathers experimental and theoretical investigations about both the geometry-dependent fracture initiation angle and the fracture strength in VO-notched polymethyl methacrylate (PMMA) specimens under mode I loading conditions. The numerical analyses revealed that despite the application of pure mode I loading on the geometrically symmetric VO-notched samples, the maximum tangential stress occurs at two points symmetrically placed on either side of the notch bisector line. The experimental tests performed on some specimens showed that a crack does not necessarily propagate along the notch bisector line. Stress-based theoretical studies were then carried out to justify the experimental findings. The conventional maximum tangential stress (MTS) criterion gave weak predictions of the fracture. Therefore, the predictions were checked with the generalized MTS (GMTS) criterion by taking into consideration the higher-order stress terms. It was demonstrated that the GMTS criterion predictions have satisfactory consistency with the experimental results of the crack initiation angle and the fracture strength.

Towards pure mode I loading in dissimilar adhesively bonded double cantilever beams

2021 ◽  
Vol 107 ◽  
pp. 102826
Author(s):  
M. Moazzami ◽  
M.R. Ayatollahi ◽  
S. Teixeira de Freitas ◽  
L.F.M. da Silva
Keyword(s):  
Mode I ◽  
Pure Mode ◽  
Cantilever Beams ◽  
Adhesively Bonded ◽  
Mode I Loading ◽  
Double Cantilever Beams

A Comparison of the Fracture Behaviour of Various Concrete Grades under Mixed Mode I/II Loading

2019 ◽  
Vol 827 ◽  
pp. 228-233
Author(s):  
Petr Miarka ◽  
Robin Janssen ◽  
Stanislav Seitl ◽  
Wouter de Corte
Keyword(s):  
Tangential Stress ◽  
High Strength Concrete ◽  
Fracture Resistance ◽  
Mixed Mode ◽  
Fracture Behaviour ◽  
High Strength ◽  
Critical Distance ◽  
Maximum Tangential Stress ◽  
Mode I ◽  
C 50

The Brazilian disc test with central notch is widely used to evaluate mixed mode I/II fracture resistance of brittle materials such as rocks and concrete. An analytical evaluation is used based on the maximum tangential stress (MTS) criterion and the generalised maximum tangential stress (GMTS) criterion. In this contribution two concrete types, a C 50/60 and a high strength concrete, were compared using the GMTS criterion. Also, the influence of critical distance rC on the fracture resistance under the mixed mode I/II was studied.

scholarly journals Crack path stability in brittle fracture under pure mode I loading

2018 ◽  
Vol 13 ◽  
pp. 735-740
Author(s):  
M.R. Ayatollahi ◽  
S.M.J. Razavi ◽  
F. Berto
Keyword(s):  
Brittle Fracture ◽  
Crack Path ◽  
Mode I ◽  
Pure Mode ◽  
Mode I Loading ◽  
Path Stability ◽  
Crack Path Stability

scholarly journals Mode I fracture characterization of human bone using the DCB test

2015 ◽  
Vol 6 (3) ◽  
pp. 355-366
Author(s):  
F.G.A. Silva ◽  
M.F.S.F. de Moura ◽  
N Dourado ◽  
F. A. M. Pereira ◽  
J.J.L. Morais ◽  
...  
Keyword(s):  
Fracture Energy ◽  
Cortical Bone ◽  
Bone Fracture ◽  
Mode I ◽  
Pure Mode ◽  
Fracture Characterization ◽  
Content Type ◽  
Human Cortical Bone ◽  
Mode I Loading

Purpose – Fracture characterization of human cortical bone under pure mode I loading was performed in this work. The purpose of this paper is to validate the proposed test and procedure concerning fracture characterization of human cortical bone under pure mode I loading. Design/methodology/approach – A miniaturized version of the double cantilever beam (DCB) test was used for the experimental tests. A data reduction scheme based on crack equivalent concept and Timoshenko beam theory is proposed to overcome difficulties inherent to crack length monitoring during the test. The application of the method propitiates an easy determination of the Resistance-curves (R-curves) that allow to define the fracture energy under mode I loading from the plateau region. The average value of fracture energy was subsequently used in a numerical analysis with element method involving cohesive zone modelling. Findings – The excellent agreement obtained reveals that the proposed test and associated methodology is quite effective concerning fracture characterization of human cortical bone under pure mode I loading. Originality/value – A miniaturized version of traditional DCB test was proposed for cortical human bone fracture characterization under mode I loading owing to size restrictions imposed by human femur. In fact, DCB specimen propitiates a longer length for self-similar crack propagation without undertaking spurious effects. As a consequence, a R-curve was obtained allowing an adequate characterization of cortical bone fracture under mode I loading.

scholarly journals Rupture analysis of rubber in the presence of a sharp V-shape notch under pure mode-I loading

2018 ◽  
Vol 146-147 ◽  
pp. 405-415 ◽  
Author(s):  
M. Heydari-Meybodi ◽  
M.R. Ayatollahi ◽  
F. Berto
Keyword(s):  
Mode I ◽  
Pure Mode ◽  
Mode I Loading
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