Mixed-mode fracture toughness versus thickness and yield strength in aluminum alloys

  • Rahman SeifiEmail author
  • Mostafa Bahri
Technical Paper


Variations in in-plane mixed-mode fracture toughness versus changes in thickness of shear CT (CTS) specimens and loading direction and effects of yield strength of different aluminum alloys have been investigated by experimental testing and numerical analysis. Several samples were made by Al2024-O, Al6061-T6 and Al7075-T6 alloys. Based on the results, increasing the thickness reduces the mixed-mode fracture toughness and near to the critical thickness, this reduction is lesser. Increase in mixed-mode loading angle for brittle materials has not significant effects on the toughness while in softer materials by changing the angle from 15° to 60°, the amount is halved. Near the mode I fracture conditions, there is no meaningful relationship between the yield strength and fracture toughness but with an increase in the second mode effects, these parameters will be proportional. The mixed-mode toughness of the alloys with different thicknesses can be calculated numerically with a precise accuracy by applying failure load in the analysis.


Mixed-mode Fracture toughness Thickness Yield strength CTS specimen 


Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest in preparing of this paper.


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Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2019

Authors and Affiliations

  1. 1.Department of Mechanical Engineering, Faculty of EngineeringBu-Ali Sina UniversityHamedanIran

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