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International Journal of Fracture

, Volume 154, Issue 1–2, pp 3–14 | Cite as

Size effect and quasi-brittle fracture: the role of FPZ

  • Xiaozhi Hu
  • Kai Duan
Original Paper

Abstract

Fracture process zone (FPZ), or the crack-tip damage zone created by crack-bridging and micro-cracking activities, in a specimen of a concrete-like material is comparable to the crack size and un-cracked ligament, so fracture is typically quasi-brittle. Increasing or decreasing the specimen size, quasi-brittle fracture transition occurs towards the toughness-controlled or strength-controlled fracture, which is known as size effect (SE). In this study it is shown that the “size-dependent” quasi-brittle fracture transition is actually due to the interaction of FPZ with the nearest structure boundary rather than the size variation, and the widely-accepted SE for geometrically-similar specimens of different sizes is only a special case of quasi-brittle fracture controlled by the FPZ/boundary interaction. Relevant SE relations are critically reviewed and explained by emphasizing the key SE mechanism, FPZ/boundary interaction.

Keywords

Fracture process zone (FPZ) Size effect (SE) Boundary effect (BE) Tensile strength Fracture toughness Scaling 

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Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.School of Mechanical EngineeringUniversity of Western AustraliaPerthAustralia
  2. 2.PELM & Department of Infrastructures, Faculty of Science, Engineering & HealthCQ-UniversityGladstoneAustralia

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