DIC method applied in the calibration of FEA model of rock-mortar cohesive interface detachment

Resumo

In civil engineering, the stability of many structures depends on the physical properties of the contact
between the concrete seated on the rocky foundation surface. Usually, they are critical structures of great
importance to society, such as: bridges, tunnels and dams. Thus, the shear behavior of rock-concrete joints is a key
factor of the structural stability. The method of cohesive zones (CZM) allows to simulate the beginning of the
formation of a crack and its propagation, without knowing the crack location or when it will start. Thus, in this
work, a numerical model was developed capable of simulating the failure due to interfacial delamination of the
contact between a structure formed by mortar seated on a rocky granite leaning surface. The calibration of the
numerical model was performed using the results of an experimental test of simple compression on a block of rock
in contact with the mortar by an inclined interface. The test was monitored using a high resolution digital camera.
The data were processed using the digital image correlation method (DIC) to obtain displacement and deformation
data. The DIC results were used to calibrate the nonlinear numerical model of the test using the bilinear method
of cohesive zone in the rock-mortar interfacial contact elements. By a parametric analysis, the parameters of the
bilinear law were determined (Maximum tensile stress and critical displacement and damage rate). Indirectly, the
rate of release of energy of critical deformation from the rupture of the contact was also estimated.