Numerical modeling of strain rate hardening effects on viscoplastic behavior of metallic materials

The main goal of the present work is to provide a finite strain elasticviscoplastic framework to numerically account for strain, strain rate hardening, and viscous effects in cold deformation of metallic materials. The aim is to provide a simple and robust numerical framework capable of modeling the main macroscopic behavior associated with high strain rate plastic deformation of metals. In order to account for strain rate hardening effects at finite strains, the hardening rule involves a rate dependent saturation hardening, and it accounts for linear hardening prevailing at latter deformation stages. The numerical formulation, finite element implementation, and constitutive modeling capabilities are assessed by means of decremental strain rate testing and constant strain rate loading followed by stress relaxation. The numerical results have demonstrated the overall framework can be an efficient numerical tool for simulation of plastic deformation processes where strain rate history effects have to be accounted for

Some numerical verification examples for plane stress elasto-viscoplasticity

This paper presents analytical, semi-analytical and numerical reference examples which can be employed for code verification of elasto-viscoplastic models under plane stress conditions. Mainly because of the overstress function the algorithms traditionally employed in elasto-plastic implementations must be rewritten to correctly impose the plane stress state along with the viscoplastic flow. The viscoplastic formulation presented here considers the strain-rate hardening effects by means of a hardening law that are assumed to have terms depending on the strain rate, which removed can represent a Voce type hardening. The proposed verification tests were employed for the numerical verification of an in-house implementation of the so-called stress-projected procedure inside the finite element method context. Although the focus of this paper is on the stressprojected algorithms the examples presented here can be employed for the verification of other algorithms intended to impose the plane stress state in viscoplasticit

The medicine is the least of the problems: following networks in adherence to AIDS treatment

This essay intends to question Bruno Latour’s methodological proposal. In research on people living with HIV and their adherence dilemmas, using Latour’s proposal, we sought to address the following issues: how does one bring the universes of people living with HIV closer, without fractioning their lives? How does one understand the relationship established between PLHIV (People living with HIV) and their medication without setting aside the issue of medication management from other experiences? Despite the obstacles, common to those who decide to follow certain itineraries (the dangers of the journey, as Brazilian author Guimarães Rosa would say), the research guided by the methodology proposed by Latour – the ethnographic methodology of the “Actor-Network Theory” – allowed us to follow the actors’ steps, although timidly and initially, without fractioning their lives and without making isolated cutouts, monitoring what happens in a network and is interconnected, interfering and suffering interference. The ethnography carried out led us through tortuous paths, forcing us to venture into confusing itineraries, networks of humans and non-humans, medications, swimming pools, NGOs, health care, and a network of relationships among people living with HIV, through the difficult paths that our interlocutors developed.Este texto buscou problematizar a proposta metodológica de Bruno Latour. Numa pesquisa sobre pessoas vivendo com HIV (Vírus da imunodeficiência humana) e seus dilemas de adesão, valendo-nos da proposta de Latour, buscamos trabalhar com as seguintes questões: como efetuar uma aproximação aos universos das pessoas vivendo com HIV sem fracionar a vida das pessoas? Como compreender as relações que a PVHIV (Pessoas vivendo com HIV) estabelece com a medicação sem separar a questão da administração medicamentosa do restante das experiências? Apesar dos percalços, comuns àqueles que se dedicam a seguir itinerários (os perigos da travessia, diria Guimarães Rosa), a pesquisa guiada pela metodologia proposta por Latour – a metodologia etnográfica da “Teoria Ator-Rede” – permitiu, ainda que tímida e inicialmente, seguir os passos de atores, sem fracionar as suas vidas, sem fazer recortes isolados, acompanhando o que acontece em rede e está interligado, interferindo e sofrendo interferências. A etnografia realizada nos levou por caminhos tortuosos, fazendo-nos embrenhar em itinerários confusos, em redes de humanos e não humanos, de remédios, piscinas, Organização Não Governamental (ONG), serviços de saúde, uma rede de relações de pessoas vivendo com HIV nos caminhos difíceis que nossos interlocutores elaboraram.Universidade Federal de São Paulo (UNIFESP)Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina PreventivaUNIFESP, Depto. de Medicina PreventivaSciEL

Impactos do Novo Regime Fiscal na saúde e educação

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Seasonally steady planetary disturbances in the troposphere and stratosphere as seen in 30 years of NCEP reanalysis data

Zonal velocity and temperature daily global reanalysis data of 30 years are used to search seasonally steady planetary disturbances in the middle troposphere (400 hPa) and middle stratosphere (10 hPa). Significant wavenumber 1, 2 and 3 modes are found. Constant phase lines of zonal velocity 1 modes exhibit significant inclination angles with respect to the meridians. The winter hemisphere generally shows a more significant presence of structures. The Northern Hemisphere (NH) exhibits all over the year a larger amount of structures and more intense amplitudes than the Southern Hemisphere (SH). Middle latitudes exhibit the most significant cases and low latitudes the least significant ones. Longitudinally oriented land-sea transitions at +- 65 deg and -35 deg latitudes appear to play a significant role for the presence of steady planetary modes. The stratosphere exhibits a much simpler picture than the troposphere. Large scale structures with respectively NE-SW (NH) and NW-SE (SH) tilts in the observed temperature and zonal velocity constant phase lines recall the quasi-stationary Rossby wave trains that favor the poleward transport of angular momentum.Fil: Alexander, Pedro Manfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina;Fil: Rossi, Mario. Universidad de Buenos Aires; Argentina

Spatio-temporal Graph-RNN for Point Cloud Prediction

In this paper, we propose an end-to-end learning network to predict future frames in a point cloud sequence. As main novelty, an initial layer learns topological information of point clouds as geometric features, to form representative spatio-temporal neighborhoods. This module is followed by multiple Graph-RNN cells. Each cell learns points dynamics (i.e., RNN states) by processing each point jointly with the spatio-temporal neighbouring points. We tested the network performance with a MINST dataset of moving digits, a synthetic human bodies motions and JPEG dynamic bodies datasets. Simulation results demonstrate that our method outperforms baseline ones that neglect geometry features information

Explaining Hierarchical Features in Dynamic Point Cloud Processing

This paper aims at bringing some light and understanding to the field of deep learning for dynamic point cloud processing. Specifically, we focus on the hierarchical features learning aspect, with the ultimate goal of understanding which features are learned at the different stages of the process and what their meaning is. Last, we bring clarity on how hierarchical components of the network affect the learned features and their importance for a successful learning model. This study is conducted for point cloud prediction tasks, useful for predicting coding applications