PSI - Issue 13

Baijian Wu et al. / Procedia Structural Integrity 13 (2018) 722–727 Baijian Wu and Keke Tang/ Structural Integrity Procedia 00 (2018) 000 – 000

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The influence of side-edge constraint on crack propagation path is demonstrated in Fig. 6. Variation of parameter  is reflective of compression-tension behaviors on concrete cell. The change of  has no appreciable effects on the path of interface crack propagation. Side-edge tensile forces create a compressive zone that in a certain degree retards crack penetrating into the matrix. In general, the four cases has similar crack propagation path.

Fig. 6. Influence of side-edge constraint on crack path

5. Concluding remarks

Cracks at biomaterial interfaces extensively exist in composites, microelectronic or engineering materials. Numerical methods such as finite element method is adopted by combining the virtual crack closure technique. Concrete is one of the most fundamental engineering materials, also possesses the interfacial challenges through the material degradation and failure. In this regard, a numerical algorithm is formulated and is further applied to study the behaviors of concrete rupture. Modelling of dynamic crack propagation at concrete matrix-aggregate interface is made possible. Influence of the side-edge constraint, the aggregate direction as well as the fracture energy of the interface, was discussed. The results show that, tensile constraint on the side edge, a smaller angle between tensile axis and aggregate, and higher fracture energy could lead to a higher rupture strength of the interface. Once the interface starts to grow, it immediately and unstably propagates to the two ends of the aggregate major axis, and further enters the matrix. The three factor influences less on the character of above rupture path. Last but not least, though the conclusion is prudently stipulated to concrete matrix with single aggregate, the numerical model can be also further modified to study the trans-scale propagations of multiple cracks in concrete materials or components. This will be discussed in the following work.

Acknowledgements

The work is under the financial support from National Natural Science Foundation of China (NSFC) under grant No. 11072060. The second author acknowledges the support from the Fundamental Research Funds for the Central Universities.

References

Barnett, D. M., Asaro, R. J., 1972. The fracture mechanics of slit-like cracks in anisotropic elastic media. Journal of the Mechanics and Physics of Solids, 20(6): 353 – 366.