FRCU - GIMCE: Grupo de Investigación de Mecánica Computacional y de Estructuras - Comunicaciones a Congresos
Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/809
Browse
4 results
Search Results
Item Vigas de gran altura de hormigón reforzado con fibras. Evaluación de la resistencia al corte(2021-06-05) Rougier, Viviana Carolina; Denardi, Miqueas Ceferino; Vercesi, Darío OrestesConcrete is very strong in compression, but it has a very low tensile strength. To improve its tensile strength, reinforcing steel is often used in the concrete. However, the reinforcement of the cementitious matrix with discrete fibers has gained increasing recognition. The addition of fibers randomly distributed as reinforcement of cement-based matrices can produce a material with improved tensile strength and deformational characteristics. Different types of fibers can be employed to reinforce concrete. Nevertheless, the use of steel fibers is particularly attractive in concrete members with high reinforcement congestion, like deep beams, when conventional stirrups can be eliminated or reduced. So, the effects of steel fibers on the shear strength of reinforced concrete deep beams were evaluated by different ways: experimental, theoretical, and numerical. A total of six beams were subjected to a concentrated load P at their center and two steel fiber volume fractions were used. Two specimens were elaborated with plain concrete and longitudinal steel reinforcement. Web reinforcement was used in one of those beams and the other was made without stirrups. The others four specimens were built with steel fibers reinforced concrete (SFRC), longitudinal steel reinforcement and without stirrups. The test results indicated that the fibers influenced the shear strength of reinforced concrete deep beams. Shear strength increased with increasing fiber volume fraction, but steel fibers could not totally replace the conventional steel stirrups. Comparisons between experimental shear strength values and predictions, using empirical models developed by different authors, showed satisfactory results. In addition, the comparison between numerical and experimental values indicated that finite element analysis (FEA) was a reliable tool to simulate nonlinear behavior of SFRC deep beams.Item Modelo bi fase del HRFA para el estudio de la influencia de la orientación y distribución de fibras de acero en la resistencia mecánica de tubos de drenaje(Asociación Argentina de Mecánica Computacional, 2019-11-05) Ferrado, Facundo Luis; Escalante, Mario Raúl; Rougier, Viviana CarolinaEn este trabajo se propone un modelo 3D para el estudio probabilístico de la capacidad resistente de tubos de Hormigón Reforzado con Fibras de Acero (HRFA), en el cual el HRFA es considerado como un material bi fase en donde las fibras son representadas como elementos discretos y aleatoriamente distribuidas. La contribución de este trabajo radica en que el modelo así propuesto en combinación con el método de Monte Carlo permite realizar un estudio probabilístico de la capacidad resistente de los tubos, así como también de la influencia que tienen sobre ella, la orientación y distribución de fibras de acero dentro de la masa de hormigón. Para ello, se simula el ensayo de tres aristas normalizado por la norma IRAM 11503, el cual es implementado en una herramienta de análisis por elementos finitos (ABAQUS c ). Se utilizan modelos constitutivos distintos para el hormigón simple y para las fibras. Finalmente, se muestran resultados de las simulaciones a través de tablas de cargas máximas, curvas carga-desplazamiento e histogramas.Item Simulation of the three edge bearing test : 3D model for the study of the strength capacity of SFRC pipes(Asociación Argentina de Mecánica Computacional, 2018-11-06) Ferrado, Facundo Luis; Escalante, Mario Raúl; Rougier, Viviana CarolinaThe use of SFRC as building material, has been expanding its possibilities beyond conventional applications. Among its new applications, SFRC pipes appear as a new reliable alternative to the common pipes which use steel mesh as reinforcement, due to the structural benefits that mean the fiber addition. In spite of the advances achieved regarding the knowledge of the behavior of SFRC as a structural material, a numerical tool which allows to predict the mechanical response of SFRC pipes is needed,this is due to the complexity of the costly experimental campaigns. In this work the mechanical behavior of SFRC pipes is numerically assessed by means of the simulation of the three edge bearing test (TEBT) according to IRAM 11503 standard through a tridimensional model, which is implemented using a finite element analysis tool. SFRC is considered as an homogeneous material described for a damage-plasticity model which consider different behaviors in tension and compression by means of stress-strain uniaxial curves. These curves are obtained from equations arising from theoretical-experimental developments of other authors. Finally the results of the simulations are shown by means of load-deflection curves, ultimate loads charts and strength distribution diagrams, which are compared with those ones obtained in a experimental campaign carried out by the authors themselves. The results are complemented with some pictures depicting the experimental campaign mentioned above, with both the equipment used during the tests as well as the failure modes of the pipes are shown.Item Numerical simulation of the three edge bearing test of steel fiber reinforced concrete pipes(Asociación Argentina de Mecánica Computacional, 2016-11-11) Ferrado, Facundo Luis; Escalante, Mario Raúl; Rougier, Viviana CarolinaHistorically, steel has been the material chosen to improve the tensile behaviour of concrete. Nowadays, the trending of replacing the traditional reinforcement bars with short and slender fibers randomly distributed in the mass concrete, is growing. This composite material made essentially of common concrete reinforced with discrete fibers is called steel fiber reinforced concrete(SFRC). In this work the mechanical behaviour of SFRC pipes is studied, simulating the diametral compression test called three edge bearing test by means of a 2d model in plane strain state. The SFRC is considered as a homogeneous material and its behaviour is represented through some damage - plasticity model (concrete damage plasticity) which takes into account the progressive reduction in the values of the elastic constants due to plastic strain and damage by means of a stiffness degradation variable. The model assumes that the main two failure mechanisms of the concrete are tensile cracking and compressive crushing, thus, the tensile and compression response is characterized through differentiated uniaxial stress-strain curves. This representation, although simplified, captures the most important features of the concrete response. The equations are solved with a commercial computational package. In addition, and as an alternative for the same problem, a case is addressed in which the SFRC is considered as an equivalent homogeneous material too, although a coupled plastic-damaged model is used where the coupling between plasticity and damage is achieved through a simultaneous solution of the plastic and the damage problem. Finally is presented a modified coupled damaged plasticity model that comes from a modification of the LublinerOller yield criterion from the adoption of a yield function of second degree in the components of the stress tensor. For the coupled damage plasticity the contribution of the fibers is considered through the classic mixture theory according to it is performed a modification of the elastic constants depending on the volumetric contribution of the fibers. Here, the problem is solved using the non-linear finite elements code PLastic Crack dynamic (PLCd) The validity of the numerical tool is performed comparing the results of the simulation with experimental data existing in the literature.