Full-field identification of elastic and shear moduli of perforated masonry walls using DIC and stiffness-based shear partition (Euler-Bernoulli vs Timoshenko)

Abstract

Digital Image Correlation (DIC) is increasingly used in masonry testing for full-field crack mapping, yet its potential for quantitative identification of elastic properties at structural scale is still not fully exploited for perforated walls where load paths split into multiple piers. This contribution presents a DIC-driven procedure to estimate the Young’s modulus E and the shear modulus G of windowed masonry walls made of three materials: clay brick masonry, calcium silicate brick masonry, and calcium silicate block masonry. Axial strains are extracted at the wall extreme fibres and converted to E using section-dependent bending stresses that account for the reduced cross-section within the window height. For G, pier-average shear strains are obtained from DIC strain fields within defined regions of interest, while pier shear forces are computed by stiffness-based partition of the applied top shear between the left and right piers. Two bounds are considered: Euler–Bernoulli theory (shear-rigid) and Timoshenko theory (shear-flexible) with a shear correction factor. The comparison clarifies how the inferred G depends on pier aspect ratio and the assumed shear deformability. Finally, a parametric study is conducted to quantify how the assumed Poisson’s ratio affects the back-calculation of E from the measured G. The results further indicate that elastic parameters obtained from standard small-scale tests (e.g., prisms or wallets) tend to overestimate the effective E and G inferred at wall scale, which can significantly bias the calibration of continuum and macro-element numerical models.