Shearography non-destructive testing of thick GFRP laminates: Numerical and experimental study on defect detection with thermal loading

Thick composite materials are commonly used as load-bearing structures in marine applications. Developing a suitable and sophisticated non-destructive testing (NDT) method for thick composites is an urgent challenge to improve the safety, reliability and maintenance of these structures. Digital shearography has become an important NDT...

Effects of initial and boundary conditions on gravel-bed river morphology

Assuming that the equilibrium geometry of river channels does not depend on their initial state but solely on boundary conditions, several formulas have been derived that relate the channel depth and width to the river bankfull discharge and bed material. However, due to the existence of a threshold for sediment motion and the strong non...

Well-posedness of Hamilton–Jacobi equations in population dynamics and applications to large deviations

We prove Freidlin–Wentzell type large deviation principles for various rescaled models in populations dynamics that have immigration and possibly harvesting: birth–death processes, Galton–Watson trees, epidemic SI models, and prey–predator models. The proofs are carried out using a general analytic approach based on the well-posedness of a...

On the Bolotin's reduced beam model versus various boundary conditions

This paper is devoted to the construction of asymptotically correct simplified models of nonlinear beam equations for various boundary conditions. V.V. Bolotin mentioned that in some cases (e.g., if compressed load is near the buckling value), the so-called „nonlinear inertia“ must be taken into account. The effect of nonlinear inertia on the...

Tunable mechanical behavior of auxetic cementitious cellular composites (CCCs): Experiments and simulations

This research presents an investigation of the compressive behavior of auxetic cementitious cellular composites (CCCs) using a combination of experiments and finite element (FE) simulations. Typical auxetic centrosymmetric geometry was used as unit cells for the cellular structure and fiber reinforced cementitious mortar were used as...

Implementation of non-trivial boundary conditions in MPM for geotechnical applications

This paper describes current work on the implementation of non-trivial boundary conditions (BCs) for improving the general applicability of the Material Point Method (MPM) to geotechnical boundary values problems. It summarises novel boundary treatments (non-trivial BCs) in MPM for (i) flow conditions, as well as (ii) the application of a...

An idealized description for the diurnal cycle of the dry atmospheric boundary layer

We present a conceptual model for the diurnal cycle of the dry atmospheric boundary layer (ABL). It may serve as a framework for future numerical studies on the transitional dynamics that characterize the ABL over land. The conceptual model enables us to define expressions for relevant physical scales as a function of the most prominent...

Parameters for the collapse of turbulence in the stratified plane Couette flow

We perform direct numerical simulation of the Couette flow as a model for the stable boundary layer. The flow evolution is investigated for combinations of the (bulk) Reynolds number and the imposed surface buoyancy flux. First, we establish what the similarities and differences are between applying a fixed buoyancy difference (Dirichlet) and...

Higher order exponential splittings for the fast Non-linear Fourier Transform of the Korteweg-De Vries equation

Non-linear Fourier Transforms (NFTs) enable the analysis of signals governed by certain non-linear evolution equations in a way that is analogous to how the conventional Fourier transform is used to analyse linear wave equations. Recently, fast numerical algorithms have been derived for the numerical computation of certain NFTs. In this paper,...