Fracture Characterization of Masonry in Compression with Acoustic Emission Analysis and Numerical Modeling

Masonry under compression exhibits complex structural interactions among brick units and mortar joints which remains a true challenge to understand. Its structural response is related to the relative mechanical properties of the bricks/blocks, the mortar and their interface. In this research, experimental and numerical analysis will be applied to deduce information on the fracture progress in masonry under compression. An extensive experimental research program includes series of compression tests on masonry samples categorized into three different scales, such as (a) small-scale couplets, (b) full-scale couplets and (c) masonry walls. Different non-destructive testing (NDT) methods such as micro-CT, digital image correlation, acoustic emission and numerical methods are applied to obtain adequate information on the triaxial behavior and fracture modes in masonry under compression. Micro-CT is applied on small-scale masonry couplets to evidence the crack initiation at a micro-scale level. Digital image correlation is applied on full-scale masonry couplets to validate if there is a strong size and shape effect on the crack initiation and propagation. An AE-based test procedure for the damage quantification in masonry under cyclic compressive loads is developed. AE critical damage limits from concrete are applied and validated in masonry. It is the first time that these AE indices are investigated in masonry. Finite element micro models are developed to predict the fracture modes in masonry under compression. The results of the numerical model are compared with experimental results and the influence of material properties on the fracture modes is also performed. Finally, masonry fracture characterization scheme from coupled NDT and numerical methods provides the detailed understanding of the fracture modes in masonry under compression. Lastly, based on numerical results, new AE-based critical damage limits is proposed.

Jaar van publicatie:2019

Toegankelijkheid:Open