Integrated Process of Laser-Assisted Machining and Laser Surface Heat Treatment

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Bin Shi ◽  
Helmi Attia
Keyword(s):  
Heat Treatment ◽  
Finite Element ◽  
Element Model ◽  
Surface Heat ◽  
Laser Surface ◽  
Fe Model ◽  
Two Dimensional ◽  
Numerical Investigations ◽  
Laser Assisted Machining ◽  
Dimensional Finite Element

A process is proposed for integrating the laser-assisted machining (LAM) and laser surface heat treatment (LSHT) in a single operation. Experimental and numerical investigations were carried out. LSHT tests were performed to investigate the effect of the process parameters on the microstructure evolution and hardenability. A methodology and an empirical model for prediction of hardened depth were proposed. A two-dimensional finite element (2D-FE) model was developed to predict the phase transformation during the LAM and LSHT processes. The optimization of the LAM process was also investigated using the developed finite element model.

Étude de la réouverture de la lagune du Havre aux Basques. I. Modélisation numérique des conditions d'écoulement

1995 ◽  
Vol 22 (1) ◽  
pp. 55-71
Author(s):  
Y. Ouellet ◽  
A. Khelifa ◽  
J.-F. Bellemare
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Element Model ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Modélisation Numérique ◽  
Tidal Flows ◽  
Dimensional Finite Element ◽  
The Stability ◽  
La Madeleine

A numerical study based on a two-dimensional finite element model has been conducted to analyze flow conditions associated with different possible designs for the reopening of Havre aux Basques lagoon, located in Îles de la Madeleine, in the middle of the Gulf of St. Lawrence. More specifically, the study has been done to better define the depth and geometry of the future channel as well as its orientation with regard to tidal flows within the inlet and the lagoon. Results obtained from the model have been compared and analyzed to put forward some recommendations about choice of a design insuring the stability of the inlet with tidal flows. Key words: numerical model, finite element, lagoon, reopening, Havre aux Basques, Îles de la Madeleine.

A finite-element model of oxygen diffusion in the pulmonary capillaries

1997 ◽  
Vol 82 (6) ◽  
pp. 2036-2044 ◽  
Author(s):  
Andreas O. Frank ◽  
C. J. Charles Chuong ◽  
Robert L. Johnson
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Oxygen Diffusion ◽  
Flow Characteristics ◽  
Element Model ◽  
Two Dimensional ◽  
Plasma Protein Concentration ◽  
Pulmonary Capillaries ◽  
Dimensional Finite Element ◽  
Barrier Surface

Frank, Andreas O., C. J. Charles Chuong, and Robert L. Johnson. A finite-element model of oxygen diffusion in the pulmonary capillaries. J. Appl. Physiol. 82(6): 2036–2044, 1997.—We determined the overall pulmonary diffusing capacity (Dl) and the diffusing capacities of the alveolar membrane (Dm) and the red blood cell (RBC) segments (De) of the diffusional pathway for O2 by using a two-dimensional finite-element model developed to represent the sheet-flow characteristics of pulmonary capillaries. An axisymmetric model was also considered to assess the effect of geometric configuration. Results showed the membrane segment contributing the major resistance, with the RBC segment resistance increasing as O2 saturation ([Formula: see text]) rises during the RBC transit: RBC contributed 7% of the total resistance at the capillary inlet ([Formula: see text] = 75%) and 30% toward the capillary end ([Formula: see text] = 95%) for a 45% hematocrit (Hct). Both Dm and Dlincreased as the Hct increased but began approaching a plateau near an Hct of 35%, due to competition between RBCs for O2 influx. Both Dm and Dl were found to be relatively insensitive (2∼4%) to changes in plasma protein concentration (28∼45%). Axisymmetric results showed similar trends for all Hct and protein concentrations but consistently overestimated the diffusing capacities (∼2.2 times), primarily because of an exaggerated air-tissue barrier surface area. The two-dimensional model correlated reasonably well with experimental data and can better represent the O2 uptake of the pulmonary capillary bed.

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