Behaviour of Masonry Walls Under Blast Loads

Abstract

Iso-damage curves for the assessment of damage due to blast loads on structures can be found in the literature. These curves seem to be an attractive way to approximately relate pressures and impulses to damage produced in different types of buildings and parts of them. In general, they have been obtained from a wide compilation of data related to damage produced in masonry houses and other buildings and structural elements in both experimental and actual explosions. These curves can be alternatively obtained with modern computers codes. This presents an advantage in the possibility of changing geometry, support conditions and material properties. However, this procedure requires an appropriate calibration of the numerical tool and the material model to insure it is able to reproduce the behaviour under blast loads precisely. The main objective of this paper is the numerical study of behaviour of masonry walls under different blast loads with variable support and geometric conditions. The results compared with experimental and analytical values contribute to the development of a useful tool for the assessment of damage in masonry elements and also other structural elements. The influence of discretization level and constitutive model type in the masonry walls response is analyzed. Two different models are considered for the walls: a box type zoning and a fragment/brick zoning. The last one presents the possibility of defining different properties for mortar and bricks. On the other hand, the erosion technique is also studied. Failure modes for different explosive charges located at variable distance are presented. The results are compared with those found in open literature and, finally, the work is concluded with useful suggestions for numerical modeling of this kind of problem.