Most of the existing concrete dams are subjected to cracking. These cracks are caused by various factors such as construction practices, curing, loads and volume change of mass concrete which reduce the efficiency, failure or instability of concrete dams. Using fracture mechanics as a new method to estimate stability and durability of concrete dams is recommended in scientific publications in w...

This paper develops an asymptotic estimation theory for nonlinear autoregressive models with conditionally heteroskedastic errors. We consider a general nonlinear autoregression of order p (AR(p)) with the conditional variance specified as a general nonlinear first order generalized autoregressive conditional heteroskedasticity (GARCH(1,1)) model. We do not require the rescaled errors to be ind...

— We propose a mathematical model for adaptive Computed Tomography acquisition whose goal is to radically reduce dosage levels. The theoretical foundation of the algorithm is nonlinear Ridgelet approximation. We show experimental results where the adaptive model produces significantly higher image quality, when compared with known non-adaptive acquisition algorithms, for the same number of proj...

Observations after earthquakes where surface fault ruptures crossed engineering facilities reveal that some structures survived the rupture almost unscathed. In some cases, the rupture path appears to divert, “avoiding” the structure. Such observations point to an interaction between the propagating rupture, the soil, and the foundation. This paper i develops a two-step nonlinear finite-element...

a Department of Physics, University of Crete and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 2208, 71003 Heraklion, Greece b Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile c Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0...

In the present article, effect of non-uniform excitation of reservoir bottom on nonlinear response of concrete gravity dams is considered. Anisotropic damage mechanics approach is used to model nonlinear behavior of mass concrete in 2D space. The tallest monolith of Pine Flat dam is selected as a case study. The horizontal and vertical components of 1967 Koyna earthquake is used to excite the s...

A compressively strained film on a substrate can wrinkle into intricate patterns. This Rapid Communication studies the evolution of the wrinkle patterns. The film is modeled as an elastic nonlinear plate and the substrate a viscoelastic foundation. A spectral method is developed to evolve the nonlinear system. When the initial film strains are isotropic, the wrinkles evolve into a pattern with ...

We study the buckling of a two-dimensional elastica floating on a bath of dense fluid, subjected to axial compression. The sinusoidal pattern predicted by the analysis of linear stability is shown to become localized above the buckling threshold. A nonlinear amplitude equation is derived for the envelope of the pattern. These results provide a simple interpretation to the wrinkle-to-fold transi...

We consider numerical approximations of a quasistatic problem modeling the sliding frictional contact with wear between a viscoelastic body and a rigid moving foundation. The contact is modeled with the Coulomb's law of dry friction and the wear is described by a version of Archard's law. The variational formulation of the problem consists of a nonlinear evolutionary equation coupled with a tim...