56 research outputs found
Energy-Consistent CoRotational Schemes for Frictional Contact Problems
In this paper, we consider the unilateral frictional contact problem of a hyperelastic body in the case of large displacements and small strains. In order to retain the linear elasticity framework, we decompose the deformation into a large global rotation and a small elastic displacement. This corotational approach is combined with a primal-dual active set strategy to tackle the contact problem. The resulting algorithm preserves both energy and angular momentum
Abstract robust coarse spaces for systems of PDEs via generalized eigenproblems in the overlaps
Coarse spaces are instrumental in obtaining scalability for domain decomposition methods for partial differential equations (PDEs). However, it is known that most popular choices of coarse spaces perform rather weakly in the presence of heterogeneities in the PDE coefficients, especially for systems of PDEs. Here, we introduce in a variational setting a new coarse space that is robust even when there are such heterogeneities. We achieve this by solving local generalized eigenvalue problems in the overlaps of subdomains that isolate the terms responsible for slow convergence. We prove a general theoretical result that rigorously establishes the robustness of the new coarse space and give some numerical examples on two and three dimensional heterogeneous PDEs and systems of PDEs that confirm this property
Computational Modeling of Silicate Glasses: A Quantitative Structure-Property Relationship Perspective
This article reviews the present state of Quantitative Structure-Property
Relationships (QSPR) in glass design and gives an outlook into future developments.
First an overview is given of the statistical methodology, with particular emphasis
to the integration of QSPR with molecular dynamics simulations to derive informative
structural descriptors. Then, the potentiality of this approach as a tool for
interpretative and predictive purposes is highlighted by a number of recent inspiring
applications
Evidence for a glassy dynamics in (Rb-NH4)2SO4 mixed compounds
An orientational glass behavior is evidenced in a mixed
crystal. Dielectric experiments (1 kHz–250 MHz) performed along the c-axis
evidenced a polydispersive relaxation process. Its temperature dependence
follows a Vogel-Fulcher law with a freezing temperature of 12 K
Hypersonic wave anomalies in Cs
The elastic properties of Cs3H(SeO4)2 are investigated by Brillouin
spectroscopy in the temperature range 20-220,°C covering the two transitions
III → II and II → I occurring at ~95°C
and ~, respectively. Phase I is known to be a protonic
conductive one. Discontinuities of elastic constants are generally observed at both
transitions, implying first orderness. In phases II and I, a slight broadening of
the Brillouin lines is detected. The results are discussed in comparison with compounds
of the families XHSeO4 (X = NH4, Rb and Cs) and CsH2BO4
(B = As and P) which also undergo a transition to a superionic phase. In the
conductive phase, it appears that the lattice anharmonicity is weaker in
Cs3H(SeO4)2 than in these other compounds
Discovering long-term polymer dynamics with generative deep neural networks.
International audienc
- …