Search results for "structural analysis"

Problemas multiplicativos relacionados con la división de fracciones : un estudio sobre su enseñanza y aprendizaje

2013

Los estudiantes tienen dificultades para asociar el enunciado de un problema multiplicativo con la operación que permite resolverlo; esta investigación identifica los tipos de problemas multiplicativos que los estudiantes reconocen como de división de fracciones. Mediante el análisis histórico-epistemológico de textos de enseñanza sobre tres épocas históricas y ocho períodos diferentes, se obtiene un listado de variables de enseñanza (algoritmos, sentidos de uso de fracción y de división de fracciones, representaciones, problemas), así como los valores de dichas variables. Se localizan en los textos consultados algunas reglas particulares y seis algoritmos generales, cuyo predominio ha vari…

Dynamic stability of plane elastic frames

1982

Abstract The stability of plane elastic frames subjected to a vertical foundation motion of the stationary, ergodic type is investigated. The equations of motion are obtained in modal co-ordinates, with account taken of many modes of vibration. The problem is subsequently reduced to the study of only the first mode of vibration. By considering a particular case, the stability domains are sketched as functions of the variation of the rigidities of the beam-column connecting joints and as functions of the number of stories.

An integral equation for damage identification of Euler-Bernulli beams under static loads

2004

A perturbation approach for the response of dynamically modified structural systems

1998

The problem of the structural analysis under changes of dynamical parameters is of particular interest. This is due to the fact that often the real structures are different from the predicted ones. In this paper, an unconditionally stable step-by-step procedure, able to evaluate the deterministic response of linear structures with modifications, is presented. The proposed procedure requires the evaluation of the transition matrix, which is the fundamental operator of the step-by-step solution, by means of a perturbation approach. This technique overcomes the difficulties connected with the evaluation of the eigenproperties of the modified structures usually required to obtain the transition…

Ricerche nella catacomba di Villagrazia di Carini

2018

The Quaderno Digitale 9 is dedicated to the archaeological researches conducted in the Early Christian catacomb of Villagrazia di Carini until year 2015. The essay of G. Schirò presents the results of the excavations carried out from 2008 to 2011 in the Gallery IX and the structural analysis of 36 burials. Marco Correra, in the second essay, presents the analysis of the types of closure of the tombs so far excavated, in comparison with other funerary contexts in Sicily, Sardinia and North Africa. Finally, Francesco Scirè and Marta Marescalchi illustrate the project drawn up for the enjoyment of the most representative sectors of the monument, whose visit was inaugurated in May 2015.

Premessa al volume: Il cubicolo X13 nella catacomba di Villagrazia di Carini. Indagini preliminari e interventi di consolidamento 2016-2019

2019

This book is dedicated to the archaeological excavations and to the consolidation of the structures of cubicle X13 in the catacomb of Villagrazia di Carini (PA). In 2015 the interesting funerary chamber was seriously damaged by the collapse of the ceiling; from 2016 to 2019, the realization of the recovery and restoration project by the Pontificia Commissione di Archeologia Sacra has been the occasion for the study of the rock-cut architectures and of the structural characteristics of the cubicle, one of the most remarkable private funerary spaces in the Early Christian and byzantine cemetery of Carini.

FE Calculation Methodology for the Thermodynamic Fatigue Analysis of an Engine Component

2006

Thermo mechanical fatigue problem is treated to define an analysis methodology permitting the strength evaluation by reliability viewpoint. The main difficulty is the lack of both theoretical and experimental information; consequently the problem is treated verifying continually the validity and the limits of the developing solution method. The main task of the activity described in this paper was the development of a numerical methodology, based on FE analyses, for the evaluation of the structural behavior of engine components subjected to thermo mechanical fatigue phenomena. The chosen application was the exhaust manifold of an IC engine; FE analyses were executed following the standard m…

Influence of secondary torsion on curved steel girder bridges with box and I-girder cross-sections

2015

Steel curved girder bridges are largely used today in motorways and railways. They are often composed of thin-walled crosssections, entirely made of steel or with an upper concrete slab. The deck may have I-girders or box cross-sections: in any case curved girders are subjected to twisting moment, associated with bending, even for dead loads. Moreover, in thin-walled sections the influence of non-uniform torsion becomes sizable with respect to Saint Venant torsion, modifying the state of tangential stresses in the section and introducing axial stresses due to warping being prevented. Open sections of I-girder bridges are especially subject to these phenomena and warping can be significant n…

Structural behavior of the old masonry bridge in the Gulf of Castellammare

2016

Abstract Masonry arch bridges represent a very significant part of the heritage of road and railway artworks all over the word and especially in the Mediterranean area, both in terms of: numbers; reduced environmental impact; and static efficiency. In these cases, the cost of maintenance is often limited to the content and channeling of surface water and control of vegetation, which can eventually take root on the joints of the masonry at the shoulders. In masonry bridges, there are no expansion joints or hinges with support equipment or trolleys, as in metal bridges and reinforced concrete ones, or paint, or resin surface protection, all items that affect the cost of maintenance. The perma…

Performance-Based Engineering of Wind-Excited Structures: A General Methodology

2016

The current prescriptive design philosophy that relies simply on meeting requirements stipulated in standards is shifting towards a performance-based design (PBD) approach for achieving designs that rationally meet society’s need for a truly safe built environment. Extensive research has facilitated the successful adoption of PBD in earthquake engineering, but the same cannot be said for wind engineering. Therefore, the need exists to initiate a similar effort by defining a framework that fully embraces the concepts of PBD during the design of building systems to resist severe wind events. This paper illustrates the development of such a PBD framework. In particular, a method is proposed sp…