Identification of non linear parameters from masonry triplet shear tests using digital image correlation

Triplet shear tests are commonly used to evaluate the strength of masonry shear walls. A conventional approach involves identifying the parameters of the Mohr-Coulomb failure criterion. Although numerous studies have proposed numerical models capable of reproducing the global experimental response, the present work distinguishes itself by coupling full-field displacement measurements obtained through Digital Image Correlation (DIC) with the identification of nonlinear material parameters within a consistent inverse framework. DIC measurements were used to prescribe experimentally measured boundary conditions in finite element simulations. A Finite Element Model Updating (FEMU) strategy was then implemented to identify the model parameters. A prior sensitivity analysis showed that displacement fields exhibited limited influence on the targeted parameters for the adopted constitutive model, which justified a force-based identification procedure. The methodology was applied to four triplet shear tests. The results demonstrated the capability of the mesoscopic model to reproduce the observed mortar joint response. Both elastic and nonlinear parameters were identified, and their associated uncertainties were quantified.