scholarly journals Preliminary investigation on homogenization of the thickness distribution in hole-flanging by SPIF

2017 ◽  
Vol 13 ◽  
pp. 124-131 ◽  
Author(s):  
D. Morales-Palma ◽  
M. Borrego ◽  
A.J. Martínez-Donaire ◽  
G. Centeno ◽  
C. Vallellano
Keyword(s):  
Thickness Distribution ◽  
Preliminary Investigation ◽  
Hole Flanging

scholarly journals Effect of Process Parameters and Preheating Temperature on Surface Roughness and Thickness Distribution in Hole Flanging using Incremental Sheet Metal Forming

2019 ◽  
Vol 8 (12S2) ◽  
pp. 84-87
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Research Work ◽  
Preheating Temperature ◽  
Incremental Sheet Metal Forming ◽  
Best Parameter ◽  
Hole Flanging

Incremental Sheet metal forming is a die less method of forming which offers high formability. In this research work; effect of step depth, tool rotation speed and preheating temperature on surface roughness and thinning of flange wall is investigated in hole flanging using incremental forming. The parameter optimization is carried out by Taguchi method. Grey relational analysis is carried out to obtain best parameter combination.

scholarly journals Effect of Process Parameters and Preheating Temperature on Surface Roughness and Thickness Distribution in Hole Flanging using Incremental Sheet Metal Forming

2019 ◽  
Vol 9 (2) ◽  
pp. 666-669
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Research Work ◽  
Preheating Temperature ◽  
Incremental Sheet Metal Forming ◽  
Best Parameter ◽  
Hole Flanging

Incremental Sheet metal forming is a die less method of forming which offers high formability. In this research work; effect of step depth, tool rotation speed and preheating temperature on surface roughness and thinning of flange wall is investigated in hole flanging using incremental forming. The parameter optimization is carried out by Taguchi method. Grey relational analysis is carried out to obtain best parameter combination.

scholarly journals Investigation of Punch Shape and Loading Path Design in Hydro-Flanging Processes of Aluminum Alloy Tubes

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 636
Author(s):  
Yeong-Maw Hwang ◽  
Hong-Nhan Pham ◽  
Hiu-Shan Rachel Tsui
Keyword(s):  
Aluminum Alloy ◽  
Thickness Distribution ◽  
Loading Path ◽  
Hydraulic Power ◽  
Hole Radius ◽  
Path Design ◽  
Hole Flanging ◽  
Loading Path Design ◽  
Punch Shape ◽  
Deform 3D

Hydro-joining is composed of hydro-piercing, hole flanging and nut-inlaying processes. In this study, a new hydro-flanging process combining hydro-piercing and hydro-flanging is proposed. An internal pressured fluid is used as the supporting medium instead of a rigid die. Three kinds of punch head shapes are designed to explore the thickness distribution of the flanged tube and the fluid leakage effects between the punch head and the flanged tube in the hydro-flanging process. A finite element code DEFORM 3D is used to simulate the tube material deformation behavior and to investigate the formability of the hydro-flanging processes of aluminum alloy tubes. The effects of various forming parameters, such as punch shapes, internal pressure, die hole diameter, etc., on the hydro-flanged tube thickness distributions are discussed. Hydro-flanging experiments are also carried out. The die hole radius is designed to make the maximum internal forming pressure needed smaller than 70 MPa, so that a general hydraulic power unit can be used to implement the proposed hole flanging experiments. The flanged thickness distributions are compared with simulation results to verify the validity of the proposed models and the designed punch head shapes.

scholarly journals Optimization of Hole-Flanging by Single Point Incremental Forming in Two Stages

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2029 ◽  
Author(s):  
Domingo Morales-Palma ◽  
Marcos Borrego ◽  
Andrés Martínez-Donaire ◽  
Gabriel Centeno ◽  
Carpóforo Vallellano
Keyword(s):  
Incremental Forming ◽  
Thickness Distribution ◽  
Single Point ◽  
Optimization Procedure ◽  
Single Point Incremental Forming ◽  
Two Stage ◽  
Element Analysis ◽  
Deformation And Failure ◽  
Explicit Finite Element ◽  
Hole Flanging

Single point incremental forming (SPIF) has been demonstrated to accomplish current trends and requirements in industry. Recent studies have applied this technology to hole-flanging by performing different forming strategies using one or multiple stages. In this work, an optimization procedure is proposed to balance fabrication time and thickness distribution along the produced flange in a two-stage variant. A detailed analytical, numerical and experimental investigation is carried out to provide, evaluate and corroborate the optimal strategy. The methodology begins by analysing the single-stage process to understand the deformation and failure mechanisms. Accordingly, a parametric two-stage SPIF strategy is proposed and evaluated by an explicit Finite Element Analysis to find the optimal parameters. The study is focused on AA7075-O sheets with different pre-cut hole diameters and considering a variety of forming tool radii. The study exposes the relevant role of the tool radius in finding the optimal hole-flanging process by the proposed two-stage SPIF.

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

Photographic Equidensitometry of High Voltage Electron Images of Thick Noncrystalline Materials

1972 ◽  
Vol 30 ◽  
pp. 594-595
Author(s):  
Keinosuke Kobayashi
Keyword(s):  
High Voltage ◽  
Linear Response ◽  
Thickness Distribution ◽  
Contour Map ◽  
Mass Thickness ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Homogeneous Particle ◽  
Photographic Emulsions ◽  
Logarithmic Relation

Equidensitometry as developed by E. Lau and W. Krug has been little used in the analysis of ordinary electron photomicrographs, yet its application to the high voltage electron images proves merits of this procedure. Proper sets (families) of equidensities as shown in the next page are able to reveal the contour map of mass thickness distribution in thick noncrystalline specimens. The change in density of the electron micrograph is directly related to the mass thickness of corresponding area in the specimen, because of the linear response of photographic emulsions to electrons and the logarithmic relation between electron opacity and mass thickness of amorphous object.This linearity is verified by equidensitometry of a spherical solid object as shown in Fig. 1a. The object is a large (1 μ) homogeneous particle of polystyrene. Fig. 1b is a composite print of three equidensities of the 1st order prepared from Fig. 1a.

A Comparison of the Ultrastructural Morphology of Hepatic Necrosis in BDF1 Mice

1981 ◽  
Vol 39 ◽  
pp. 586-587
Author(s):  
Becky Jackson
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Preliminary Investigation ◽  
Hepatic Necrosis ◽  
Hepatic Tissue ◽  
Pronounced Increase ◽  
Glycogen Store ◽  
Ultrastructural Morphology ◽  
Mitochondrial Integrity ◽  
Glycogen Stores

Preliminary investigation has indicated similarity in hepatic ultrastructural morphology in nutritional deprivation, and cyanide induced hepatic necrosis. Analysis of hepatic tissue has indicated disruption of intracellular membranes, specifically, reduction in rough endoplasmic reticulum (RER) mitochondrial integrity, and glycogen stores. An increase in smooth endoplasmic reticulum (SER) portion was observed.To further investigate the apparent equivalence of necrotic morphology, ultrastructura1ly, BDF1 mice were subjected to senescence, nutritional deprevation, potassium cyanide (KCN) induced toxemia, and acetaminophen induced toxemia. Controls were utilized to ellucidate non-necrotic hepatocellular normals. U1trastructura1 investigation of controls (Fig. 1) shows densely granular RER, abundant glycogen stores, and morphologically normal mitochondria. Subjects with acetaminophen induced necrosis exhibit reduced normal RER with increased levels of dialated, vesicular RER in apparent conversion to SER (Fig. 2), loss of mitochondrial integrity, and glycogen store reduction. Senescent subjects exhibit a pronounced increase in SER and loss of glycogen store. (Fig. 3). Investigation of the senescent SER at high magnification (Fig. 5) indicates that the SER is arising from degranulating and vesiculating RER.

Ultrastructural Effects of Acute Kepone Treatment in Rats

1976 ◽  
Vol 34 ◽  
pp. 286-287
Author(s):  
Richard L. Klein ◽  
Åsa K. Thureson-Klein ◽  
Harihara M. Mehendale
Keyword(s):  
Neurological Disorders ◽  
Corn Oil ◽  
Preliminary Investigation ◽  
Reproductive Capacity ◽  
Ultrastructural Changes ◽  
Lipid Deposition ◽  
Severe Toxicity ◽  
Sprague Dawley ◽  
Ether Anesthesia ◽  
Sprague Dawley Rats

KeponeR (decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one) is an insecticide effective against ants and roaches. It can cause severe toxicity in fishes, birds, rodents and man. Prominent effects include hepatic lipid deposition and hypertrophy, impairment of reproductive capacity and neurological disorders. Mitochondrial oligomycin-sensitive Mg2+-ATPase is also inhibited. The present study is a preliminary investigation of tissue ultrastructural changes accompanying physiological signs of acute toxicity, which after two days treatment include: pronounced hypersensitivity and tremor, various degrees of anorexia and adipsia, and decreased weight gain.Three different series of adult male Sprague-Dawley rats (Charles River or CD-I) were treated by intubation with Kepone in corn oil at a dose of 50 mg per kg for 3 successive days or at 200 ppm in food for 8 days. After ether anesthesia, rats were immediately perfused via a cannula in the left ventricle with 4% p-formaldehyde and 0.5% glutaraldehyde in Millonig's phosphate buffer at pH 7.2 for 20-30 min at 22°C.

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