Contribution of Interface Fracture Mechanism on Fracture Propagation Trajectory of Heterogeneous Asphalt Composites

Asphalt mixture is a type of textured composite material made of aggregates and mastic part. Overall strength and failure behavior in such materials depends on the texture or heterogeneity of the mixture. In particular, the crack growth mechanism from the tip of the pre-crack is significantly affected by the texture of the asphalt composite and environmental conditions. The crack can extend through the soft mastic, tight aggregates or interface of the mastic/aggregates. In this research, by performing some fracture tests on a typical asphalt mixture with different test specimens under mode I, mixed mode I/II and mixed mode I/III, the fracture resistance and trajectory of propagating crack is studied at two low and medium temperatures (i.e., −15 and +15 °C). The load bearing capacity and the fracture resistance of the tested asphalt samples increases by decreasing the temperature. It is also shown that a significant part of fracture plane passes through the soft mastic and boundary of aggregates (i.e., the interface of aggregates and mastic) and only about 10–15% of the fracture surface of the propagating crack passes via the tight aggregates by breaking them. This percentage decreases for mode II and III loading conditions and higher testing temperatures. Compared to brittle and isotropic materials, the fracture path of the asphalt mixture shows more deviation, and this deviation increases for those mixtures containing coarser aggregates in the ligament and tested under medium temperature conditions.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.827.228 ◽

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.

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A New Idea of Pure Mode-I Fracture Test of Bonded Bi-Materials

ASME 2010 Pressure Vessels and Piping Conference: Volume 3 ◽

10.1115/pvp2010-25759 ◽

2010 ◽

Author(s):

Zhenyu Ouyang ◽

Gefu Ji ◽

Guoqiang Li ◽

Su-Seng Pang ◽

Samuel Ibekwe

Keyword(s):

Mixed Mode ◽

Dissimilar Materials ◽

Test Method ◽

Interface Fracture ◽

Mode I ◽

Mixed Mode Fracture ◽

Pure Mode ◽

Fracture Test ◽

Engineering Structures ◽

Material Systems

Bi-material systems in which two dissimilar materials are adhesively joined by a thin adhesive interlayer have been widely used in a variety of modern industries and engineering structures. There are two fundamental issues that need to be adequately addressed: (1) Fracture of bonded bi-materials is mixed mode: Mode-I (pure peel) and Mode-II (pure shear). Fracture test implementation of bi-material systems with the traditional Mode-I methods will induce a noticeable mixed mode fracture due to the disrupted symmetry by the bi-material configuration; (2) The popular cohesive zone models (CZMs) for accurate fracture simulations require more than a single parameter (toughness) as is the case in the traditional linear elastic fracture mechanics (LEFM). Thus, J-integral is highly preferred. It can not only capture more accurate toughness value by considering the root rotation effect, but also facilitate the experimental characterizations of the interfacial cohesive laws, which naturally include all required parameters by CZMs. Motivated by these two important issues, a novel idea is proposed in the present work to realize and characterize the pure Mode-I nonlinear interface fracture between bonded dissimilar materials: Despite the approximation with the elementary beam theories, the accuracy is validated by numerical simulations. The proposed approach may be considered as a promising candidate for the future standard Mode-I test method of adhesively bonded dissimilar materials due to its obvious simplicity and accuracy.

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Mixed Mode I/II Fracture Resistance of Various Civil Engineering Materials by Selected Criteria

Procedia Structural Integrity ◽

10.1016/j.prostr.2021.10.038 ◽

2021 ◽

Vol 33 ◽

pp. 312-319

Author(s):

Stanislav Seitl ◽

Julian Z. Andrade Lizarro ◽

Petr Miarka

Keyword(s):

Fracture Resistance ◽

Mixed Mode ◽

Civil Engineering ◽

Mode I ◽

Engineering Materials

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On Approximately Realizing and Characterizing Pure Mode-I Interface Fracture Between Bonded Dissimilar Materials

Journal of Applied Mechanics ◽

10.1115/1.4003366 ◽

2011 ◽

Vol 78 (3) ◽

Cited By ~ 19

Author(s):

Zhenyu Ouyang ◽

Gefu Ji ◽

Guoqiang Li

Keyword(s):

Mixed Mode ◽

Dissimilar Materials ◽

Interfacial Fracture ◽

Interface Fracture ◽

Mode I ◽

Mode Ii ◽

Pure Mode ◽

J Integral ◽

Mode I Fracture ◽

Fracture Behaviors

Bimaterial systems in which two dissimilar materials are adhesively joined by a thin adhesive interlayer have been widely used in a variety of modern industries and engineering structures. It is well known that interfacial fracture is the most common failure mode for these bimaterial systems. Particularly, the interface fracture is a mixed mode in nature mode-I (pure peel) and mode-II (pure shear) due to the disrupted symmetry by the bimaterial configuration. Obviously, characterizing individual fracture modes, especially mode-I fracture, is essential in understanding and modeling the complex mixed mode fracture problems. Meanwhile, the J-integral is a highly preferred means to characterize the interfacial fracture behaviors of a bimaterial system because it cannot only capture more accurate toughness value, but also facilitate an experimental characterization of interfacial traction-separation laws (cohesive laws). Motivated by these important issues, a novel idea is proposed in the present work to realize and characterize the pure mode-I nonlinear interface fracture between bonded dissimilar materials. First, a nearly pure mode-I fracture test can be simply realized for a wide range of bimaterial systems by almost eliminating the mode-II component based on a special and simple configuration obtained in this work. Then, the concise forms of the J-integral are derived and used to characterize the interfacial fracture behaviors associated with classical and shear deformation beam theories. The proposed approach may be considered as a promising candidate for the future standard mode-I test method of bimaterial systems due to its obvious accuracy, simplicity, and applicability, as demonstrated by the numerical and experimental results.

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