http://www.atamturktur.com daily 1 2008-05-26T20:53:50Z http://www.atamturktur.com/publications/a-guide-for-the-finite-element-analysis-of-historic-load-bearing-masonry-structures The assessment of unreinforced masonry structures, especially in arched or vaulted forms, is difficult to undertake in practice. A structural engineer is often confronted with a standing, apparently competent, structure that seems to defy most of the rules of structural behavior as incorporated in modern building codes. The engineer must then choose between reinforcing the structure according to a modern understanding of material strength and structural behavior or trying to make sense of the behavior and anticipated strength of the structure on a more fundamental level. A manual has been developed to introduce a sympathetic structural engineer to some of the principles of unreinforced masonry and to provide some basic instructions in preparing a finite element model of complex vaulted masonry structures using widely available modern tools of structural analysis (Boothby et al. 2006). Based on the manual, this paper gives guidance on the application of finite element tools for linear and non-linear assessment of arches. Detailed instructions are given for development of geometric models, solid models and meshing and entering material properties, boundary conditions and loads for models of complex three-dimensional structures, such as domes and vaults. No publisher sezer publications 2008-12-19T04:26:19Z Article http://www.atamturktur.com/publications/extension-of-large-scale-modal-analysis-techniques-to-historic-masonry-vaults As a result of the increasing demand for the condition assessment and rehabilitation of historic structures, the application of modal analysis techniques to large-scale masonry buildings is a growing area for the field of experimental mechanics. Although a large body of literature discusses testing on various forms of laboratory specimens, modal testing on a large-scale historic masonry structures has completely different practical issues that challenge the selection of testing variables, equipment, and set-up. Recently, the reading room masonry domes of the State Education Building were subject to experimental modal analysis to enhance the quality of the numerical model. The purpose of these experiments is to identify the dynamic parameters of the vaulted structure and to justify two modeling assumptions established during the finite element analysis: masonry behaves as a linearly elastic material under existing loading conditions, and the construction imperfections have minimal influence on global behavior. The paper also shows that the use of experimental modal analysis can be extended to the investigation of the dynamic interaction between adjacent components of a large-scale structure and to the examination of the elastic support conditions exerted by the adjacent elements. No publisher sezer publications 2008-12-19T04:26:57Z Article http://www.atamturktur.com/publications/sensitivity-of-modal-parameters-of-historic-monuments-to-geometric-distortions A unique opportunity to investigate the sensitivity of modal parameters of complex vaulted masonry systems to geometric distortions due to abrupt changes in boundary conditions is found in Beverley Minster, UK. Over the last eight centuries, the accumulated support settlements of the buttresses have pulled the main nave walls outwards, causing severe Sabouret cracks along the edges of masonry vaults. At certain locations, the separation of the walls from the nave vaults has reached 150 mm, while bays closer to the main crossing tower remain integral with the walls. Due to large deformations, the crown of the damaged vaults sags approximately 200 mm relative to the undamaged vaults. The sag of the crown and inverse curvature of the damaged vaults are visually observable. To compare different states of the vaulted system, representative sections of both undamaged and damaged vaults were subjected to modal analyses by measurable hammer impact excitation. The deviations of the natural frequencies and mode shapes between the two cases are quantified. The discrepancies of the modal parameters are found to be as low as the measurement errors, and thus insufficient to yield conclusions on the state of damage to the vaults. However, magnitudes of frequency response functions are significantly greater for the damaged vaults. No publisher sezer publications 2008-12-19T04:28:40Z Article http://www.atamturktur.com/publications/structural-assessment-of-guastavino-domes Rafael Guastavino refined the technique of erecting thin terra-cotta tile, a thousand year old building system of ‘Catalan Vaulting.’ His company was involved with more than 1000 buildings in North America between the 1880s and the 1960s. Although Guastavino tile vaulting contributed to many prestigious buildings of that time, the structural behavior of this construction system has received little or almost no attention in the literature. It is the intention of this thesis to study this empirically designed system by using tools of modern engineering: experimental modal analysis, thin elastic shell theory and finite element analysis. No publisher sezer © 2006 Huriye Sezer Atamturktur publications 2008-06-19T03:50:08Z Multipage article http://www.atamturktur.com/publications/structural-modeling-of-the-vaults-of-st-julien-in-couleuvre-france The twelfth-century church of St. Julien in Couleuvre, France is characteristic of Bourbonnais Romanesque construction practices, with relatively heavy barrel vaults with transverse arches surmounting a nave of modest height. The thrust of the nave vaulting is resisted by vaulted aisles and external buttresses. In the present study, the static behavior of the vaults of St. Julien is studied by the development of a finite element model. The predicted dynamic behavior of this model is validated by experimental modal analysis, by comparison of experimentally and analytically determined frequencies and mode shapes. Boundary conditions and material properties are established by obtaining reasonable match between the experimental and analytical results. The validated analytical model is studied for stress distribution, magnitudes of horizontal thrust, horizontal/vertical reaction ratios, and for the effectiveness of the buttressing scheme. No publisher sezer publications 2008-12-19T04:31:31Z Article