S. ZHANG (1) and K. BEYER (2)
(1) PostDoc, Earthquake Engineering and Structural Dynamics Laboratory (EESD), IIC, ENAC, École Polytechnique
Fédérale de Lausanne (EPFL), Lausanne, 1015 Switzerland, firstname.lastname@example.org
(2) Associate Professor, Earthquake Engineering and Structural Dynamics Laboratory (EESD), IIC, ENAC, École
Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015 Switzerland, email@example.com
ABSTRACT: Seismic assessment of unreinforced masonry structures remains a challenge. This paper summarizes recent developments of an advanced simulation method based on the cohesive zone model (CZM) in a finite element framework. Cohesive elements are often used to simulate dynamic fracture. To consider contact and friction, a new node-to-node algorithm is implemented in the open-source code Akantu, which offers a parallel computing model. Based on the proposed framework, two types of tests are investigated: the shear test, which is a basic material test to determine parameters such as the cohesion and friction coefficient, and the diagonal compression test, which is a standard masonry material test to determine the nominal diagonal tensile strength and shear modulus of masonry. The simulation results correspond well with experimental results. To represent and study the influence of the micro-structure of the stone masonry on the force-displacement behaviour, a versatile typology generator was developed. To further quantify the micro-structure of stone masonry typology, an algorithm to calculate the Line of Minimum Trace (LMT) automatically from pictures of masonry patterns was developed. Typical samples obtained from the masonry typology generator are then simulated under compression and shear-compression loading conditions and the correlation between the geometrical indexes and the masonry strengths evaluated.
KEYWORDS: detailed micro-modelling approach, cohesive zone model, shear test, diagonal compression test, masonry typology generator, interlocking.