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Influence of Bond Pattern on the in-plane Behavior of URM Piers
No full textThe overall seismic resistance of unreinforced masonry (URM) systems that exhibit box-behavior mainly relies on the lateral force capacity of structural components. Despite the fact that it is widely accepted that masonry bond pattern might considerably affect the in-plane performance of URM members, this aspect has not fully addressed experimentally or numerically. In this paper, calibrated numerical models, developed within the framework of the Distinct Element Method, are used to simulate the quasi-static lateral response of URM piers under several combinations of boundary conditions, vertical pressures and aspect ratios, as well as a large number of typically-employed periodic and quasi-periodic bond patterns. The employment of time, size and mass scaling, and dynamic relaxation procedures, combined with the introduction of equivalent interface properties to represent the effect of cyclic damage through monotonic loading schemes, provided a significant reduction of computational cost, thus enabling a comprehensive parametric study to be carried out within an acceptable timeframe. The results show that the bond pattern has an appreciable influence on the response of laterally-loaded URM panels, motivating the possibility of including this aspect in the assessment of existing URM structures. Analytical formulations were also inferred by fitting numerical data, thus enabling the findings of this work to be readily implemented in assessment using simplified models
Distinct element modelling of the in-plane cyclic response of URM walls subjected to shear-compression
No full textA new membrane equilibrium solution for masonry railway bridges: The case study of Marsh Lane Bridge
No full textMasonry railways bridges were built and are still in use all over Europe and in many other countries all over the world. Limit analysis is widely adopted to assess the equilibrium of these structures under self and train loads and, mainly, assuming uniaxial stresses only in the span direction. In the last decade, some of these bridges, as our case study, have been subjected to detailed structural health monitoring (SHM) campaigns whose primary outcome is that these structures exhibit biaxial stresses. In this paper, within the framework of the Heyman masonry unilateral model, an application of membrane equilibrium analysis (MEA) is presented. MEA provides an efficient approach to account for biaxial stress states and, thus, taking into account beneficial 3D effects for load capacity analyses. This paper illustrates how various assumptions of the membrane behaviour yield a range of potential equilibrium solutions, all of which demonstrate higher capacity than the traditional 2D assessment methods
A new membrane equilibrium solution for masonry railway bridges: the case study of Marsh Lane Bridge
No full textMasonry railways bridges were built and are still in use all over Europe and in many other countries all over the world. Limit analysis is widely adopted to assess the equilibrium of these structures under self and train loads and, mainly, assuming uniaxial stresses only in the span direction. In the last decade, some of these bridges, as our case study, have been subjected to detailed structural health monitoring (SHM) campaigns whose primary outcome is that these structures exhibit biaxial stresses. In this paper, within the framework of the Heyman masonry unilateral model, an application of membrane equilibrium analysis (MEA) is presented. MEA provides an efficient approach to account for biaxial stress states and, thus, taking into account beneficial 3D effects for load capacity analyses. This paper illustrates how various assumptions of the membrane behaviour yield a range of potential equilibrium solutions, all of which demonstrate higher capacity than the traditional 2D assessment methods
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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