Influence of rebar diameter in concrete cracking studied using a discrete crack approach

The ability to model fracture propagation is critical to predict the structural response of a concrete member and possible failure mechanisms. Even for structures under normal service loads, good estimations on the overall deflections and associated stiffness are highly dependent on the onset of fracture and resulting crack pattern, both directly related with the tension-stiffening effect. With the aim of developing robust models to capture this behaviour, a preliminary numerical study is herein presented on the influence of rebar diameter in the cracking pattern of concrete beams captured numerically. Focus is first given to the performance of the numerical model and its mesh objectivity. Experimental results from concrete beams tested under flexural loads are adopted for validation. Two very distinct rebar diameters are used to assess the ability of the model in predicting the average crack opening, maximum crack opening and average crack spacing for a wide range of loads.ARC DE150101703, ARC DP14010052

HST Observations of the Central-Cusp Globular Cluster NGC 6752. The Effect of Binary Stars on the Luminosity Function in the Core

We consider the effect of binary stars on the main-sequence luminosity functions observed in the core of globular clusters, with specific reference to NGC 6752. We find that mass segregation results in an increased binary fraction at fainter magnitudes along the main-sequence. If this effect is not taken into account when analyzing luminosity functions, erroneous conclusions can be drawn regarding the distribution of single stars, and the dynamical state of the cluster. In the core of NGC 6752, our HST data reveal a flat luminosity function, in agreement with previous results. However, when we correct for the increasing binary fraction at faint magnitudes, the LF begins to fall immediately below the turn-off. This effect appears to be confined to the inner core radius of the cluster.Comment: 10 pages, 3 figures Accepted to ApJ Lett Vol 513 Number

Base arruinada.

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Mancha-de-bipolaris-do-milho.

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Especialização fisiológica de isolados de Exserohilum turcicum para milho e sorgo no Brasil.

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Manejo de doenças na lavoura.

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Reação de cultivares de milho à ferrugem-polissora em casa de vegetação.

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