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Elastic-Plastic and Quasi-Brittle Fracture

  • Xiaozhi Hu
  • Li Liang
Living reference work entry

Abstract

This chapter presents a simple Elastic-Plastic and Quasi-Brittle Fracture Approach that can be used by graduate students and design engineers in their structural integrity analyses to determine safe design loads or to predict critical failure loads. The simple model can also be used to extrapolate the tensile strength and fracture toughness KIC of various metals and composites from elastic-plastic fracture results of small test samples, which otherwise would require impractically large specimens for the fracture toughness measurements and well-polished specimens for the strength measurements. Elastic-plastic fracture of metals and quasi-brittle fracture of coarse-structured brittle composites such as concrete and rock can also be fairly accurately predicted by the predictive model if both strength and toughness are known. The model is derived by a simple modification of the stress intensity factor commonly used in Linear Elastic Fracture Mechanics (LEFM). Experimental results of AISI-1040 like carbon steel and Aluminum Alloy 6061 and concrete are used to verify the new approach. The new design model can be applied to different fracture situations from strength-controlled failure to LEFM KIC-controlled fracture and the elastic-plastic and quasi-brittle fracture region (or non-LEFM fracture) between the two distinct strength and toughness territories. The model also explains the limitations of LEFM imposed by the stringent requirements for the fracture toughness KIC measurements and the reason why Elastic and Plastic Fracture Mechanics (EPFM) is necessary to most structural integrity analyses.

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Copyright information

© Crown Copyright 2018

Authors and Affiliations

  1. 1.School of Mechanical and Chemical EngineeringUniversity of Western AustraliaPerthAustralia
  2. 2.School College of Resources and Civil EngineeringNortheastern UniversityShenyangPeople’s Republic of China

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