An Enhanced Finite Element Macro-Model for the Realistic Simulation of Localized Cracks in Masonry Structures: A Large-Scale Application

ABSTRACT

Finite element macro-modeling approaches are widely used for the analysis of large-scale masonry structures. Despite their efficiency, they still face two important challenges: the realistic representation of damage and a reasonable independency of the numerical results to the used discretization. In this work, the classical smeared crack approach is enhanced with a crack-tracking algorithm, originating from the analysis of localized cracking in quasi-brittle materials. The proposed algorithm is for the first time applied to a large-scale wall exhibiting multiple shear and flexural cracking. Discussion covers structural aspects, as the response of the structure under different assumptions regarding the floor rigidity, but also numerical issues, commonly overlooked in the simulation of large structures, such the mesh-dependency of the numerical results.     

Byzantine-Muslim conspiracies against the crusades: history and myth

This article examines Latin allegations of Byzantine-Muslim conspiracies against the crusades in the course of the twelfth century, the charges surviving in various chronicles, reports and letters. While their sensational elements have been noted, the Latin accounts portraying Byzantine rulers as allies of the ‘infidels’ against the crusades and the crusader states have generally been taken more or less at face value by modern scholars. A closer examination discloses how these allegations of Byzantine-Muslim collusion were based on rumour, which mainly evolved and flourished among the rank and file of the crusader armies. They eventually found their way into the chronicles, having become more outlandish in transmission. The functions they fulfilled ranged from creating a scapegoat for the failures of the Crusade of 1101 and Second Crusade, to interpretation and explanation, or rather misinterpretation, in the case of the Third Crusade. Despite the fact that, in general, these theories do not seem to have appealed to Latin emperors, kings, and nobles, paradoxically it was a noble of the Fourth Crusade, Baldwin IX of Flanders, together with his clerical advisers, who finally exploited them in May and June 1204 in order to justify the Latin conquest of Christian Constantinople.     

Crusaders and mercenaries: the west-European soldiers of the Laskarids of Nicaea (1204–1258)

The so-called empire of Nicaea was one of the new political entities that emerged in the aftermath of the Fourth Crusade in 1204. The raison d'être of Nicaea was the recovery of Constantinople and the restoration of the Byzantine Empire. Consequently, the Nicaean rulers were almost constantly involved in wars against the Latin empire of Constantinople. Nevertheless, west-European soldiers made up a large part of the Nicaean armies. This article examines the impact of these troops on the military ideology and military organization of Nicaea during the reign of the rulers of the Laskarid dynasty.