Analysis of the Fracture of Reinforced Concrete Flat Elements Subjected to Explosions. Experimental Procedure and Numerical Validation

Many of the material models most frequently used for the numerical simulation of the behavior of concrete when subjected to high strain rates have been originally developed for the simulation of ballistic impact. Therefore, they are plasticity-based models in which the compressive behavior is modeled in a complex way, while their tensile failure criterion is of a rather simpler nature. As concrete elements usually fail in tensión when subjected to blast loading, available concrete material models for high strain rates may not represent accurately their real behavior. In this research work an experimental program of reinforced concrete fíat elements subjected to blast load is presented. Altogether four detonation tests are conducted, in which 12 slabs of two different concrete types are subjected to the same blast load. The results of the experimental program are then used for the development and adjustment of numerical tools needed in the modeling of concrete elements subjected to blast.

Influencia de la velocidad de deformación en el modo de rotura de vigas de hormigón armado de alta resistencia

Gran parte de los edificios e infraestructuras que son susceptibles de ser objeto de un atentado terrorista están sustentados por una estructura portante de hormigón armado. El comportamiento de estructuras de hormigón armado está bien caracterizado ante solicitaciones estáticas, por el contrario, existen todavía incertidumbres sobre el comportamiento ante cargas impulsivas como la que provoca una explosión. Por este motivo en este trabajo se estudia un mismo esquema estructural ante dos solicitaciones de distinta velocidad de deformación, con el objeto de comprobar su influencia en el modo de fallo de la estructura. Se parte de una campaña experimental desarrollada por la Agencia de Defensa de Suecia sobre vigas de hormigón armado de alta resistencia, a partir de la cual se desarrollan estudios analíticos y simulaciones numéricas. Se comprueba que ante carga impulsiva las vigas tienen una resistencia mayor que ante carga estática, si bien con cuantías altas de armado pueden presentarse modos de fallo frágiles, lo que debe ser tenido en cuenta en el diseño de estructuras de hormigón armado para que sean seguras ante explosiones.

Proyecto de ordenacion del monte nº 19 bis, denominado "Comas de Rubio y obaga de San Juan" del partido judicial de Seo de Urgel, provincia de Lerida

Hemos dividido el estudio del presente Proyecto en tres partes o títulos. El Título primero trata del Inventario del monte y comprende el Tratamiento de la masa y elección del método de Ordenación y los fundamentos y el Trazado de la misma». Y el Título Tercero trata del Plan Especial y en él se estudia la cuantía y localización de los aprovechamientos, la valoración de los mismos y las mejoras más importantes a realizar.

Memoria histórica de lo ocurrido en Valencia en su gloriosa revolución desde 23 de mayo de 1808, hasta fines del mismo año, y de la causa formada contra el Padre Fr. Juan Rico, Vicente González Moreno, narcioso Rubio y otros

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Fracture of concrete structural members subjected to blast

If reinforced concrete structures are to be safe under extreme impulsive loadings such as explosions, a broad understanding of the fracture mechanics of concrete under such events is needed. Most buildings and infrastructures which are likely to be subjected to terrorist attacks are borne by a reinforced concrete (RC) structure. Up to some years ago, the traditional method used to study the ability of RC structures to withstand explosions consisted on a choice between handmade calculations, affordable but inaccurate and unreliable, and full scale experimental tests involving explosions, expensive and not available for many civil institutions. In this context, during the last years numerical simulations have arisen as the most effective method to analyze structures under such events. However, for accurate numerical simulations, reliable constitutive models are needed. Assuming that failure of concrete elements subjected to blast is primarily governed by the tensile behavior, a constitutive model has been built that accounts only for failure under tension while it behaves as elastic without failure under compression. Failure under tension is based on the Cohesive Crack Model. Moreover, the constitutive model has been used to simulate the experimental structural response of reinforced concrete slabs subjected to blast. The results of the numerical simulations with the aforementioned constitutive model show its ability of representing accurately the structural response of the RC elements under study. The simplicity of the model, which does not account for failure under compression, as already mentioned, confirms that the ability of reinforced concrete structures to withstand blast loads is primarily governed by tensile strength.

Experimental and numerical analysis of concrete Slabs subjected to Blast

This paper summarizes the research activities focused on the behaviour of concrete and concrete structures subjected to blast loading carried out by the Department of Materials Science of the Technical University of Madrid (PUM). These activities comprise the design and construction of a test bench that allows for testing up to four planar concrete specimens with one single explosion, the study of the performance of different protection concepts for concrete structures and, finally, the development of a numerical model for the simulation of concrete structural elements subjected to blast. Up to date 6 different types of concrete have been studied, from plain normal strength concrete, to high strength concrete, including also fibre reinforced concretes with different types of fibres. The numerical model is based on the Cohesive Crack Model approach, and has been developed for the LSDYNA finite element code through a user programmed subroutine. Despite its simplicity, the model is able to predict the failure patterns of the concrete slabs tested with a high level of accuracy

Behaviour of Concrete Structural Members Subjected to Air Blast Loading

Numerical analysis is a suitable tool in the design of complex reinforced concrete structures under extreme impulsive loadings such as impacts or explosions at close range. Such events may be the result of terrorist attacks. Reinforced concrete is commonly used for buildings and infrastructures. For this reason, the ability to accurately run numerical simulations of concrete elements subjected to blast loading is needed. In this context, reliable constitutive models for concrete are of capital importance. In this research numerical simulations using two different constitutive models for concrete (Continuous Surface Cap Model and Brittle Damage Model) have been carried out using LS-DYNA. Two experimental benchmark tests have been taken as reference. The results of the numerical simulations with the aforementioned constitutive models show different abilities to accurately represent the structural response of the reinforced concrete elements studied.

Relacion i memorial ajustado a ... los autos, e informaciones hechas por ... Don Rodrigo Marin i Rubio Obispo ... de Jaen, i a pedimiento de la ... i que se declaren por de dicho santo martyr los huessos que se hallaron en la bobeda de el altar mayor de la ... cathedral de Baeza ... el año ... de mil setenciento i veinte i nueve

Sign.: A-L2

Mystico epithalamio : cantico nupcial armonioso ... en el desposorio sagrado ... con ... Christo ... siendo en el siglo Doña Josepha Duran, Rubio, Tallada y Salinas, en la religion la Mad.e Teresa Josepha de Jesus en el ... convento de Carmelitas Descalzas de San Joseph de ... Valencia

Texto fechado en 1753

Gustavo Fernández Valbuena: Algo sobre sus trabajos arqueológicos y arquitectónicos

Gustavo Fernández Valbuena: Algo sobre sus trabajos arqueológicos y arquitectónicos

O direito como ordem e hermenêutica : a filosofia do direito de Nelson Saldanha / Gustavo Just. --

Inclui bibliografia.

A não-discriminação como direito fundamental e as redes municipais de proteção a minorias sexuais - LGBT / Alexandre Gustavo Melo Franco Bahia. --

Inclui bibliografia.

Primeiro decênio da Aladi : princípios e intituiições / Gustavo Margarinos. --

Traduzido por Oswaldo da Costa e Silva.