Rafael Estevez

We present a coupled experimental and theoretical analysis of failure in brittle materials, PMMA being a
case study. After presenting the main PMMA fracture within a cohesive zone methodology, we examine
fracture emanating from V-notch instead of a natural crack commonly considered in fracture mechanics.
Plates containing Rhombus holes are investigated experimentally, under uniaxial compression. A two steps
crack propagation is observed, with a first abrupt crack initiation followed by controlled crack growth.
The force at crack initiation decreases and the extent of spontaneous crack increases with notch angle.
This is investigated by comparing a cohesive model description and the coupled criterion framework.
Once the parameters calibrated, both descriptions are able to capture the main experimental features. The
influence of the cohesive traction-separation profile on the predictions is examined. Some comments on
the identification of parameters involved in a phase fields description for failure will be reported.