Modified Erichsen Cupping Test for Copper, Brass, Aluminium and Stainless Steel

Reddy, M. Rama Narasimha; Theja, M. S. Ravi; Tilak, M. Gangadhar

doi:10.9756/sijifbm/v6i2/0102550102

Cited by 6 publications

(3 citation statements)

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“…Many authors studied the simple tension test and the cupping test to investigate the material formability. Reddy et al [6] studied the basic forming characteristics of sheet metals from tensile tests. High strain hardening exponents proved to undergo large uniform strains during biaxial stretching operations.…”

Section: Dunckelmeyer Et Al [3]mentioning

confidence: 99%

Formability in Hole Expansion of 2-Ply (Brass/Aluminum) Sheet Using a Ball-Shaped Punch

El-Abden

Abdelrahman

2018

JES. Journal of Engineering Sciences

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Hole expansion process (HE) of metallic sheets is used to the manufacture of many products like parts for the household appliances, automotive, medical and electrical industries. Due to the importance of brass and aluminum in the sheet metal industry, the present work presents an experimental investigation of the formability in the HE process of 2-ply sheet (brass supported by an aluminum sheet) using a ball-shaped punch. The main objective of is to investigate the effects of the pre-hole diameter, type of support on the forming loads, occurrence of maximum load, limiting expansion ratio (LER), and fracture modes. 1 mm thick brass and 3 mm thick w Aluminum were used. Holes were drilled in the specimen center on an upright drill. Hole diameters were 3, 6, 8, 10, 12 and 14 mm respectively. Uniaxial tension, cupping tests and HE experiments were performed for brass supported either by blind or holed Aluminum sheet. Results showed that the force required to expand the hole, the position at which the maximum force was reached, fracture mode and forming limits were dependent on the pre-hole diameter and type and condition of support. It was concluded that in HE of brass specimens supported by (either a blind or holed) Aluminum sheet, the force required to expand the hole and the position at which the maximum force was reached decreased as the pre-hole diameter of the brass specimen increased. Fracture mode proved to depend on the type of support (blind or holed) and the hole diameter in both brass sheet and supporting Aluminum sheet. Forming limit curve (FLC's) could be constructed for the range of hole diameters in both brass and Aluminum sheets showing safe and unsafe regions in the HE process assuming two criteria: occurrence of failures in the brass sheet and occurrence of failures in the supporting Aluminum sheet. Such curves are of distinguished industrial importance in determining the success or failure in the HE process.

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Section: Dunckelmeyer Et Al [3]mentioning

confidence: 99%

Formability in Hole Expansion of 2-Ply (Brass/Aluminum) Sheet Using a Ball-Shaped Punch

El-Abden

Abdelrahman

2018

JES. Journal of Engineering Sciences

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“…Historically the Erichsen cupping test [3] was used to assess the quality of sheet metal, so was typically concerned with the formability of the sheet metal and the point at which through-thickness failure occurs [4,5]. The stretch formability effect on the crystalline structure of the metal has also been examined extensively for structural components as any defects introduced to the sheet during forming could be detrimental [6,7].…”

Section: Introductionmentioning

confidence: 99%

Quantification of coating surface strains in Erichsen cupping tests

et al. 2019

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Thermosetting polyester-based coatings are used to produce pre-painted metal in the coil coating industry. The coated steel sheet is formed into white goods and architectural cladding, which involves large deformations of the metal and results in large strains in the coating. The Erichsen cupping test is a standard method used to assess the formability, ductility and adhesion of coatings, which induces similar strains to those experienced during forming. It is a qualitative and robust quality control method, but the behaviour of coatings during the test has never been previously studied quantitatively. Failure of coatings on sheet metal during forming is a strain-governed process, so understanding the behaviour of a coating in the Erichsen cupping test will allow the formability, material properties and chemical structure of the polymer to be linked more closely, enabling the development of better coatings. A finite element model has been developed to calculate the coating surface strains for any level of indentation during the test and has been validated using the surface strains during cupping measured by digital image correlation. A master curve of the maximum strain versus the indentation depth (Erichsen index) has been determined. This allows the strain to failure of the coating on a substrate, a critical material property which is otherwise difficult and laborious to obtain, to be simply determined from the Erichsen test for the first time. The relationship between the Erichsen index and maximum surface strain presented here enables users to obtain this material property both from future tests and from the results of historic tests (as many coating suppliers and users have extensive databases of Erichsen test results stretching back many years). This novel framework provides a quantitative method to analyse the performance of coatings used in the coil industry, redeveloping a century-old technique.

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“…Such an assessment significantly affects the ability to predict the behavior of the sheet metal during forming and obtaining a specific geometry of the product and its mechanical properties. Therefore, in the pro-cess of developing sheet metal forming, standard experimental methods have become very helpfull, such as the Erichsen test [7]. The energy solution commonly used in this respect (finding a decrease of the force during sheet metal deformation indicating crack appearance) has often been replaced by more advanced assessment methods.…”

Section: Introductionmentioning

confidence: 99%

Archives of Metallurgy and Materials

Jasiński¹,

Kocańda²,

Morawiński³

et al. 2019

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Advanced vision method of analysis of the Erichsen cupping test based on laser speckle is presented in this work. This method proved to be useful for expanding the range of information on material formability for two commonly used grades of steel sheets: DC04 and DC01. The authors present a complex methodology and experimental procedure that allows not only to determine the standard Erichsen index but also to follow the material deformation stages immediately preceding the occurrence of the crack. Accurate determination of these characteristics in the sheet metal forming would be an important application, especially for automotive industry. However, the sheet metal forming is a very complex manufacturing process and its success depends on many factors. Therefore, attention is focused in this study on better understanding of the Erichsen index in combination with the material deformation history.

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Modified Erichsen Cupping Test for Copper, Brass, Aluminium and Stainless Steel

Cited by 6 publications

References 0 publications

Formability in Hole Expansion of 2-Ply (Brass/Aluminum) Sheet Using a Ball-Shaped Punch

Formability in Hole Expansion of 2-Ply (Brass/Aluminum) Sheet Using a Ball-Shaped Punch

Quantification of coating surface strains in Erichsen cupping tests

Archives of Metallurgy and Materials

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