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P Español

Publications and source records attributed to P Español.

8 recordsLinked to original sources
PubMed2005

Mechanisms for dynamic crack branching in brittle elastic solids: strain field kinematics and reflected surface waves.

We report on a numerical simulation study of dynamic fracture in strip-shaped plates in which we implement a fracture criterion that fully respects mode-I symmetry. The crack dynamics is studied as a function of the length of the initial notch. The cracks show accelerated straight motion until branching appears. We show that branching can be triggered by two different mechanisms: namely, the kinematics of the strain field and back-reflected surface waves traveling on the crack lip. We also propose a qualitative explanation for the kinematic branching mechanism in terms of the effects of the lattice discretization on Yoffe's stress field. The kinematic branching mechanism is understood by analyzing the disconnection times of the nodes ahead and aside of the crack tip.

Journal Article↗
PubMed2001

Thermodynamically consistent mesoscopic fluid particle model.

We present a finite volume Lagrangian discretization of the continuum equations of hydrodynamics through the Voronoi tessellation. We then show that a slight modification of these discrete equations satisfies the first and second laws of thermodynamics. This is done by casting the model into the GENERIC structure. The GENERIC structure ensures thermodynamic consistency and allows for the introduction of correct thermal fluctuations in simple terms. In this way, we obtain a consistent discrete model for Lagrangian fluctuating hydrodynamics. Simulation results are presented that show the validity of the model for simulating hydrodynamic problems at mesoscopic scales.

Journal Article↗
PubMed1999

Dynamical regimes in the dissipative particle dynamics model.

We discuss theoretically the behavior of the velocity autocorrelation function in the dissipative particle dynamics (DPD) model. Two dynamical regimes are identified depending on the dimensionless model parameters. For low values of the dimensional friction, a mean field behavior is observed in which the kinetic theory for the DPD model provides good predictions. For high values of the friction, collective hydrodynamic effects are dominant. We have performed numerical simulations that validate the theory presented.

Journal Article↗