Bulge formation in strip drawing with light reduction

J. P. Zhang; M. Merkwae; G. S. Baker

doi:10.1007/bf02833945

Bulge Formation in Strip Drawing with Light Reductions in Area

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1967_182_040_02 ◽

1967 ◽

Vol 182 (1) ◽

pp. 521-530 ◽

Cited By ~ 11

Author(s):

R. W. Johnson ◽

G. W. Rowe

Keyword(s):

Plane Strain ◽

Experimental Studies ◽

Simple Analysis ◽

Strip Drawing ◽

Cold Worked ◽

Bulge Formation ◽

Equilibrium Height

This paper presents some theoretical and experimental studies of the phenomenon known as bulge formation, during drawing with light reductions under conditions of plane strain. Experimental observations of the initiation of bulging agree approximately with values predicted by earlier theories. The development of the bulge as drawing proceeds has not hitherto been studied. A simple analysis is presented which predicts the growth and equilibrium height of the bulge and the influence of friction. This is substantiated by measurements with cold-worked aluminium.

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Submerged Macrophyte Control Using Plastic Blankets

Water Science & Technology ◽

10.2166/wst.1994.0172 ◽

1994 ◽

Vol 29 (4) ◽

pp. 119-126

Author(s):

D. R. Carter ◽

S. Carter ◽

J. L. Allen

Keyword(s):

Plant Species ◽

Sediment Accumulation ◽

Submerged Macrophyte ◽

Light Reduction ◽

Control Options ◽

Macrophyte Growth ◽

Gravel Pits ◽

End Use ◽

Potential Area

Penrith Lakes Scheme is concerned with the rehabilitation of gravel pits to create a system of large recreational lakes. A potential submerged macrophyte problem has been identified in an existing man-made lake. The need to control the macrophytes is dependent on the proposed end use of the lakes and the potential area of invasion. A variety of control options were assessed. Plastic blankets were tested to determine their effectiveness in controlling macrophyte growth specifically in swimming and boat access areas. Comparisons of clear, black and black woven blankets were conducted. Experiments revealed that 90% of the plants under the black and black woven blankets died within six weeks. Under clear blankets plants were reduced by between 20%-90%. Analysis showed that significant interactions occurred between sites and treatments and times, from which it can be inferred that none are independent of each other. Success in the reduction of macrophytes appears dependent on such factors as plant species, sediment accumulation and light reduction.

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The Role of Bars for Secular Bulge Formation

The Formation of Galactic Bulges ◽

10.1017/cbo9780511564611.014 ◽

2000 ◽

pp. 95-114

Author(s):

D. Pfenniger

Keyword(s):

Bulge Formation

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The Interaction between the Sheet/Tool Surface Texture and the Friction/Galling Behaviour on Aluminium Deep Drawing Operations

Metals ◽

10.3390/met11060979 ◽

2021 ◽

Vol 11 (6) ◽

pp. 979

Author(s):

Alaitz Zabala ◽

Lander Galdos ◽

Chris Childs ◽

Iñigo Llavori ◽

Andrea Aginagalde ◽

...

Keyword(s):

Lightweight Design ◽

Severity Index ◽

Tribological Behaviour ◽

Die Surface ◽

Tool Surface ◽

Strip Drawing ◽

Aluminium Sheets ◽

Increased Susceptibility

The increasing demands for lightweight design in the transport industry have led to an extensive use of lightweight materials such as aluminium alloys. The forming of aluminium sheets however presents significant challenges due to the low formability and the increased susceptibility to galling. The use of tailored workpieces and controlled die roughness surfaces are common strategies to improve the tribological behaviour, whilst galling is still not well understood. This work is aimed at analysing the interplay between the sheet and tool surface roughness on the friction and galling performance. Different degrees of Electro Discharge Texturing (EDT) textures were generated in AA1050 material strips, and tooling presenting different polishing degrees were prepared. Strip drawing tests were carried out to model the tribological condition and results were corroborated through cup drawing tests. A new galling severity index (GSI) is presented for a quick and quantitative determination of both galling occurrence and severity. The present study underlines the key role of die topography and the potential of die surface functionalization for galling prevention.

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Spatial and Temporal Distribution of Cattle Dung and Nutrient Cycling in Integrated Crop–Livestock Systems

Agronomy ◽

10.3390/agronomy10050672 ◽

2020 ◽

Vol 10 (5) ◽

pp. 672

Author(s):

Sandoval Carpinelli ◽

Adriel Ferreira da Fonseca ◽

Pedro Henrique Weirich Neto ◽

Santos Henrique Brant Dias ◽

Laíse da Silveira Pontes

Keyword(s):

Nutrient Cycling ◽

Temporal Distribution ◽

Nutrient Release ◽

Cattle Dung ◽

Total N ◽

Light Reduction ◽

Residue Decomposition ◽

Thiessen Polygon ◽

The Impact ◽

Livestock Systems

Residue decomposition from cattle dung is crucial in the nutrient cycling process in Integrated Crop–Livestock Systems (ICLS). It also involves the impact of the presence of trees exerted on excreta distribution, as well as nutrient cycling. The objectives of this research included (i) mapping the distribution of cattle dung in two ICLS, i.e., with and without trees, CLT and CL, respectively, and (ii) quantification of dry matter decomposition and nutrient release (nitrogen—N, phosphorus—P, potassium—K, and sulphur—S) from cattle dung in both systems. The cattle dung excluded boxes were set out from July 2018 to October 2018 (pasture phase), and retrieved after 1, 7, 14, 21, 28, 56 and 84 days (during the grazing period). The initial concentrations of N (~19 g kg−1), P (~9 g kg−1), K (~16 g kg−1), and S (~8 g kg−1) in the cattle dung showed no differences. The total N, P, K and S released from the cattle dung residues were less in the CLT system (2.2 kg ha−1 of N; 0.7 kg ha−1 of P; 2.2 kg ha−1 of K and 0.6 kg ha−1 of S), compared to the CL (4.2 kg ha−1 of N; 1.4 kg ha−1 of P; 3.6 kg ha−1 of K and 1.1 kg ha−1 of S). Lesser quantities of cattle dung were observed in the CLT (1810) compared to the CL (2652), caused by the lower stocking rate, on average, in this system (721 in the CL vs. 393 kg ha−1 in the CLT) because of the reduced amount of pasture in the CLT systems (−41%), probably due to light reduction (−42%). The density of the excreta was determined using the Thiessen polygon area. The CL system revealed a higher concentration of faeces at locations near the water points, gate and fences. The CLT affects the spatial distribution of the dung, causing uniformity. Therefore, these results strengthen the need to understand the nutrient release patterns from cattle dung to progress fertilisation management.

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Role of Winds, Starbursts, and Activity in Bulge Formation

The Formation of Galactic Bulges ◽

10.1017/cbo9780511564611.012 ◽

2000 ◽

pp. 76-82

Author(s):

B.G. Elmegreen

Keyword(s):

Bulge Formation

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Effect of transfer layers on friction and wear mechanisms in strip drawing tests of commercially coated forming tools

Wear ◽

10.1016/j.wear.2021.203733 ◽

2021 ◽

pp. 203733

Author(s):

A.F. Tavares ◽

A.P.O. Lopes ◽

E.A. Mesquita ◽

D.T. Almeida ◽

J.H.C. Souza ◽

...

Keyword(s):

Wear Mechanisms ◽

Friction And Wear ◽

Friction And Wear Mechanisms ◽

Strip Drawing ◽

Forming Tools

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Characterisation of the opening behavior of multilayer films with cohesive failure mechanism by in situ peel tests in the ESEM

Journal of Plastic Film & Sheeting ◽

10.1177/87560879211025572 ◽

2021 ◽

pp. 875608792110255

Author(s):

M Heuser ◽

A Zankel ◽

C Mayrhofer ◽

K Reincke ◽

B Langer ◽

...

Keyword(s):

Multilayer Structure ◽

Peel Test ◽

Multilayer Films ◽

Cohesive Failure ◽

Packaging Process ◽

Flexible Packaging ◽

Alignment Angle ◽

Peel Tests ◽

Bulge Formation

In this work, peel tests inside the chamber of an ESEM ( in situ peel tests) are described with heat-sealed test specimens of packaging systems made of multilayer films that simulate different flexible packaging types, according to the packaging line used. The in situ peel tests provided evidence to describe the influence of three different main aspects of the packaging process in relation to the opening behavior of the sealing packages. The investigated aspects are the peel angle, the alignment angle between the orientation of the multilayer films and the seal, and the bulge formation as a consequence of inadequate sealing parameters. In situ peel tests enabled the differentiation between peel angle and local (micro) peel angle, which results from the overall stiffness of the multilayer structure film. Alignment angles of 90° and 45° were found to produce similar opening forces. Images showing the formation of various new local micro fissures on new planes during the in situ peel test explained how the opening force can be dramatically increased during the tearing of two sealed multilayer films.

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