Search results for "rocking"
showing 8 items of 8 documents
Rocking of rigid block on nonlinear flexible foundation
2017
Abstract The two prime models used currently to describe rocking of rigid bodies, the Housner’s model and the Winkler foundation model, can capture some of the salient features of the physics of this important problem. These two models involve either null or linear interaction between the block and the foundation. Hopefully, some additional aspects of the problem can be captured by an enhanced nonlinear model for the base-foundation interaction. In this regard, what it is adopted in this paper is the Hunt and Crossley’s nonlinear impact force model in which the impact/contact force is represented by springs in parallel with nonlinear dampers. In this regard, a proper mathematical formulatio…
Analysis of block random rocking on nonlinear flexible foundation
2020
Abstract In this paper the rocking response of a rigid block randomly excited at its foundation is examined. A nonlinear flexible foundation model is considered accounting for the possibility of uplifting in the case of strong excitation. Specifically, based on an appropriate nonlinear impact force model, the foundation is treated as a bed of continuously distributed springs in parallel with nonlinear dampers. The statistics of the rocking response is examined by an analytical procedure which involves a combination of static condensation and stochastic linearization methods. In this manner, repeated numerical integration of the highly nonlinear differential equations of motion is circumvent…
Effect of steel collars on the seismic behaviour of granite and heavy stone columns
2013
Granite and heavy stone circular columns could be often find in the cultural heritage among ancient churches and historical buildings in all the Mediterranean area. Their good strength properties allowed to carry great load values, while their bright colours and aesthetical characteristics have been used by a lot of ancient architects to achieve structural solutions with great visual impact. Even if such materials have great compressive strength values, the environmental effects, such as long term effects and thermal loads, could damage the structural members, by cracking them. In this way the slenderness of the column increases, and the presence of an imposed ground motion could be very da…
Effect of steel collars on the seismic behaviour of axially-cracked historical stone columns
2014
Granite and heavy stone circular columns could often be found in the cultural heritage among ancient churches and historical buildings in all the Mediterranean area. Their good strength properties allow them to carry big load values, while their bright colours and aesthetical characteristics were used by a lot of architects in the past to achieve structural solutions with great visual impact.Though such materials have great compressive strength values, environmental effects, especially long term effects, can damage the structural members, by cracking them. In this way the slenderness of the column increases, and the presence of an imposed ground motion can be very dangerous, since the colum…
Formación de estructuras no lineales mediante control de la fase en sistemas fotorrefractivos
2018
Esta tesis doctoral se ha realizado en el campo de la Óptica No Lineal experimental, dentro de un marco de investigación básica. El objeto de estudio es la manipulación experimental de estructuras que pueden emerger en la sección transversal de un haz láser bajo determinadas condiciones, y que además están caracterizadas por su fase: como, por ejemplo, vórtices, solitones o dominios de fase. Como elemento activo no lineal que contribuye a la generación de este tipo de estructuras, se utilizan diferentes tipos cristal fotorrefractivos (PRCs) con tiempos de respuesta largos como el BaTiO3 y el SBN o tiempos cortos como el KTLN. El presente manuscrito está redactado como un compendio de artícu…
Nonlinear rocking of rigid blocks on flexible foundation: Analysis and experiments
2017
Abstract Primarily, two models are commonly used to describe rocking of rigid bodies; the Housner model, and the Winkler foundation model. The first deals with the motion of a rigid block rocking about its base corners on a rigid foundation. The second deals with the motion of a rigid block rocking and bouncing on a flexible foundation of distributed linear springs and dashpots (Winkler foundation). These models are two-dimensional and can capture some of the features of the physics of the problem. Clearly, there are additional aspects of the problem which may be captured by an enhanced nonlinear model for the base-foundation interaction. In this regard, what it is adopted in this paper is …
Dynamic behaviour of cracked granite and marble columns retrofitted with steel collars
2014
Marble and heavy stone columns are widely diffused in ancient churches and historical buildings in all the Mediterranean area. Their good mechanical properties allowed carrying great load values, while their bright colours and aesthetical characteristics have been used by a lot of ancient architects to achieve structural solutions with great visual impact. Despite their good compressive strength, marble columns could be damaged from environmental effects (e.g. longterm effects or thermal loads), which could crack the structural members. In this way, the slenderness of the column increases drastically and the presence of an imposed ground shaking could be critical, since the column will be m…
Rocking behaviour of multi-block columns subjected to pulse-typeground motion accelerations
2016
Ancient columns, made with a variety of materials such as marble, granite, stone or masonry are an important part of theEuropean cultural heritage. In particular columns of ancient temples in Greece and Sicily which support only the architrave arecharacterized by small axial load values. This feature together with the slenderness typical of these structural members clearlyhighlights as the evaluation of the rocking behaviour is a key aspect of their safety assessment and maintenance. It has to be notedthat the rocking response of rectangular cross-sectional columns modelled as monolithic rigid elements, has been widely investigatedsince the first theoretical study carried out by Housner (19…