Analysis of Crack Coalescence in Concrete Using Neural Networks.

Fractures in the forms of joints and microcracks are commonly found in concretes, and their failure mechanism strongly depends on the crack coalescence pattern between pre-existing flaws. The determination of the failure behavior of nonpersistent joints is an engineering problem that involves several parameters as mechanical properties of concrete, normal stress and the ratio of joint surface to total shear surface. The impact of these parameters on the crack coalescence is investigated through the use of computational tools called neural networks. A number of networks of threshold logic units were tested, with adjustable weights. The computational method for the training process was a back-propagation learning algorithm. In this paper, the input data for crack coalescence consists of values of geotechnical and geometrical parameters. As an output, the network estimates the crack type coalescence (i.e., mode I, mode II, or mixed mode I-II) that can be used for stability analysis of concrete structures. The performance of the network is measured and the results are compared to those obtained by means of the experimental method. [ABSTRACT FROM AUTHOR]