Materials and Structures

, Volume 22, Issue 5, pp 364–373 | Cite as

Fracture mechanics of brick masonry: size effects and snap-back analysis

  • Pietro Bocca
  • Alberto Carpinteri
  • Silvio Valente


Fracture energy,G F, and the critical value of stress-intensity factor,K IC, are determined for brick masonry specimens tested in bending with different notch depths. The experimental results are compared with numerical simulations, obtained through a cohesive crack model developed originally for concrete. Theoretical and experimental load-deflection curves present very similar softening branches. In some cases, a snap-back instability is predicted by the model and confirmed by the experimental data. A size-scale transition appears evident from an ultimate strength collapse at the ligament to a brittle fracture due to stress-intensification. Such a transition demonstrates that LEFM is a very suitable model for brick masonry structures at the usual size-scale. A non-dimensional brittleness number is introduced as a measure of the LEFM applicability.


Crack Opening Displacement Linear Elastic Fracture Mecha Cohesive Zone Crack Mouth Opening Displacement Notch Depth 



Crack length


Young's modulus


Ultimate tensile strength


Fracture energy


Stress-intensity factor (critical value)


Support span

L, H, B

Length, depth, thickness of the specimen




Loading point displacement


Poisson ratio


Area under theP-δ curve


Stress acting on the crack surfaces


Crack opening displacement


Critical value of the crack opening displacement


Vector of the crack opening displacements


Matrix of the coefficients of influence (nodal forces)


Vector of the nodal forces


Vector of the coefficients of influence (external load)


Vector of the crack opening displacements due to the specimen weight


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Copyright information

© RILEM 1989

Authors and Affiliations

  • Pietro Bocca
    • 1
  • Alberto Carpinteri
    • 2
  • Silvio Valente
    • 2
  1. 1.Istituto Universitario di Architettura di VeneziaVeneziaItaly
  2. 2.Dipartimento di Ingegneria StrutturalePolitecnico di TorinoTorinoItaly

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