Dislocaton-Free Zone Model of Fracture Under Reverse Loading

2009 ◽  
pp. 433-433-12
Author(s):  
S-J Chang ◽  
SM Ohr
Keyword(s):  
Zone Model ◽  
Free Zone ◽  
Reverse Loading

scholarly journals TEORIAS DO DESENVOLVIMENTO REGIONAL: O MODELO ZONA FRANCA DE MANAUS E A 4ª REVOLUÇÃO INDUSTRIAL / Theories of regional development: the Manaus free zone model and the 4th industrial revolution

Informe GEPEC ◽  
2021 ◽  
Vol 25 (2) ◽  
pp. 107-124
Author(s):  
Michele Lins Aracaty e Silva ◽  
Mauro Maurício Barbosa Lucas ◽  
Marcílio Lima de Oliveira
Keyword(s):  
Regional Development ◽  
Industrial Revolution ◽  
Zone Model ◽  
Free Zone

Desde a sua concepção, idealização, ampliação e reformulação, o modelo Zona Franca de Manaus (ZFM) já passou por pelo menos cinco fases se analisado com base nas Teorias do Desenvolvimento Regional. Estas, foram moldadas levando-se em consideração as transformações econômicas mundiais e se reestruturaram formando os grupos de teorias.  Para efeito didático, este trabalho terá como base o terceiro grupo de Teorias de Desenvolvimento Regional. Além disso, a disseminação de um novo paradigma industrial também será abordado neste trabalho, trata-se da 4ª Revolução Industrial ou Indústria 4.0. Assim, temos como objetivo analisar o modelo ZFM na 4ª Revolução industrial, baseando-se nas teorias do desenvolvimento regional. Para tanto, foi feito um estudo bibliográfico e documental com o uso do método descritivo e explicativo. Por fim, pode-se dizer que já é notório a adequação das indústrias do Polo Industrial de Manaus (PIM) dentro desse novo conceito de 4ª RI ou Indústria 4.0.

How to Measure a Dislocation’s Breakthrough Stress to Estimate the Grain Boundary Resistance against Slip Transfer Based on the DFZ-Model of Fracture

2016 ◽  
Vol 258 ◽  
pp. 93-96 ◽  
Author(s):  
Florian Schaefer ◽  
Matthias Thielen ◽  
Michael Marx ◽  
Christian Motz
Keyword(s):  
Dislocation Density ◽  
Grain Boundary ◽  
Plastic Zone ◽  
Density Distribution ◽  
Fatigue Cracks ◽  
Local Stress ◽  
Boundary Resistance ◽  
Zone Model ◽  
Free Zone ◽  
Slip Transfer

Stage-I-fatigue-cracks are used as highly localized dislocation sources with well-known Burger’s vectors to study the interaction between dislocations and grain boundaries. This interaction in the plastic zone is of particular interest to understand the fluctuating crack growth in the very short crack regime. In the case of a blocked slip band the dislocations pile up at the grain boundary causing a local stress concentration. The resulting local stress distribution is calculated based on measurements of the dislocation density distribution in the plastic zone. For this purpose the slip line profiles were measured by AFM, the dislocation density distribution was determined and the dislocation-free zone model of fracture (DFZ) was validated. With this it is possible to quantify the grain boundary resistance and to combine geometric and stress approach for grain boundary resistance against slip transfer.

On the Relations between the Threshold Values of the Fatigue Crack Growth and the Cyclic Deformation Behavior of Materials

2007 ◽  
Vol 353-358 ◽  
pp. 1053-1056
Author(s):  
Yi Sun ◽  
Rui Zhang ◽  
Jian Min Qu
Keyword(s):  
Fatigue Crack ◽  
Cyclic Loading ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Loading Test ◽  
Free Zone

In the present paper, the relation between fatigue crack growth threshold and material’s cyclic saturation behavior is investigated. The dislocation-free zone (DFZ) model is used to determine the dislocation distribution ahead of the crack tip. A cohesive zone model is developed to determine the stress field of the DFZ under cyclic loading. The effect of cyclic loading makes the plastic zone hardening (or softening), which raises the stress level in DFZ, and may lead to fracture. It is found that the near threshold characteristics are mostly determined by the cyclic deformation behavior of the material, and might be theoretically determinable from the standard cyclic loading test.

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