Results 51 to 60 of about 22,063 (297)

Symmetry Reduction in Symplectic and Poisson Geometry [PDF]

open access: yesLetters in Mathematical Physics, 2004
The paper presents a self-contained overview of various reduction techniques for symplectic and Poisson manifolds possessing symmetries. First, the standard Marsden-Weinstein symplectic reduction is presented. Then the optimal momentum map (a notion due to the authors) is introduced and its relation to generalized distributions is explained.
Ortega, Juan-Pablo, Ratiu, Tudor, S.
openaire   +2 more sources

Evaluating Energy Absorption Performance of Filled Lattice Structures

open access: yesAdvanced Engineering Materials, EarlyView.
Maximum stress must be considered to robustly evaluate energy absorber designs. This approach was applied to compare all types of absorbers in a single Ashby diagram and determine the utility of filling lattice voids with a second material. High‐performance fillers can improve the performance of lattices that are limited by buckling or catastrophic ...
Christian Bonney   +2 more
wiley   +1 more source

Poisson Doubly Warped Product Manifolds

open access: yesMathematics, 2023
This article generalizes some geometric structures on warped product manifolds equipped with a Poisson structure to doubly warped products of pseudo-Riemannian manifolds equipped with a doubly warped Poisson structure.
Ibrahim Al-Dayel   +2 more
doaj   +1 more source

Phase Field Failure Modeling: Brittle‐Ductile Dual‐Phase Microstructures under Compressive Loading

open access: yesAdvanced Engineering Materials, EarlyView.
The approach by Amor and the approach by Miehe and Zhang for asymmetric damage behavior in the phase field method for fracture are compared regarding their fitness for microcrack‐based failure modeling. The comparison is performed for the case of a dual‐phase microstructure with a brittle and a ductile constituent.
Jakob Huber, Jan Torgersen, Ewald Werner
wiley   +1 more source

Microstructure‐Controlled Crack Propagation and Fracture Resistance in MoSiBTiC Alloy Revealed by Multiscale Extended Finite Element Method Modeling

open access: yesAdvanced Engineering Materials, EarlyView.
A two‐dimensional multiscale finite element analysis framework was established for the first‐generation MoSiBTiC alloy, and the mechanical and fracture‐related parameters of the constituent phases were calibrated through experiments and simulations. The framework provides a basis for analyzing crack propagation behavior in its complex microstructure ...
Junfeng Du   +4 more
wiley   +1 more source

Interference modeling and analysis in 3-dimensional directional UAV networks based on stochastic geometry

open access: yesICT Express, 2019
In this paper, we model and characterize interference of directional unmanned aerial vehicle (UAV) networks based on stochastic geometry, where each UAV is equipped with a directional antenna and it communicates with another UAV that is located in the ...
Eunmi Chu, Jong Min Kim, Bang Chul Jung
doaj   +1 more source

Poisson geometry of directed networks in a disk [PDF]

open access: yesSelecta Mathematica, 2009
We investigate Poisson properties of Postnikov's map from the space of edge weights of a planar directed network into the Grassmannian. We show that this map is Poisson if the space of edge weights is equipped with a representative of a 6-parameter family of universal quadratic Poisson brackets and the Grasmannian is viewed as a Poisson homogeneous ...
Gekhtman, Michael   +2 more
openaire   +2 more sources

Polynomial Poisson algebras: Gel'fand-Kirillov problem and Poisson spectra [PDF]

open access: yes, 2014
We study the fields of fractions and the Poisson spectra of polynomial Poisson algebras. First we investigate a Poisson birational equivalence problem for polynomial Poisson algebras over a field of arbitrary characteristic.
Lecoutre, César
core  

Fatigue Crack Initiation and Growth in Nanocrystalline Ni at Multiple Length‐Scales

open access: yesAdvanced Engineering Materials, EarlyView.
Overview of miniaturized in situ SEM fatigue setup and resultant fatigue crack growth data for nanocrystalline Ni. The presented study focuses on the analysis of fatigue crack growth rate (FCGR) in focused ion beam‐notched microcantilevers prepared from nanocrystalline (NC) Ni as a model material.
Igor Moravcik   +7 more
wiley   +1 more source

Tailoring Functional Properties of Ti–Ni–Cu Shape Memory Alloy Thin Films for MEMS Actuators

open access: yesAdvanced Engineering Materials, EarlyView.
A comprehensive study of critical parameters required to develop well‐performing Ti–Ni–Cu thin film shape memory alloy microactuators is provided. Materials science and device integration aspects are integrated by addressing structural and physical relationships using complementary characterization techniques as well as a practical fabrication solution
Elaheh Akbarnejad   +6 more
wiley   +1 more source

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