A novel modified deep drawing cup test with grooved specimens to reduce the effect of friction on the Forming Limit Curve

A novel modified deep drawing cup test with grooved specimens to reduce the effect of friction on the Forming Limit Curve

Článek WoS

This paper presents a proposal for a modified deep drawing cup test and its evaluation for the determination of the Forming Limit Curve (FLC), which is one of the most widely used characteristics for defining forming limits in sheet metal forming. The primary objective is to use the deep drawing cup test to streamline FLC determination across a broader spectrum of strain states and, through the modification, to eliminate the influence of friction on the tested material. Furthermore, specific specimen geometries and dimensions are proposed to ensure the evaluation of the entire forming limit curve. The optimized specimen design allows for covering the full range of major and minor strains, from uniaxial tension through plane strain to near-uniform biaxial tension, with the additional capability of investigating multiple thicknesses on a single specimen. In this study, the test is applied to X5CrNi18-10 (1.4301) austenitic stainless steel. Validation of the methodology and the accuracy of the results are verified theoretically using Finite Element Method (FEM) numerical simulations and practically through experimental testing on the selected material with a thickness of 0.5 mm. During the experimental procedures, strains are recorded and evaluated using Digital Image Correlation (DIC). In this case, surface major and minor strain analysis is performed using only a single camera, which simplifies the evaluation process. For comprehensive validation, the results are compared with the well-established and standardized Nakajima method for FLC determination.

This paper presents a proposal for a modified deep drawing cup test and its evaluation for the determination of the Forming Limit Curve (FLC), which is one of the most widely used characteristics for defining forming limits in sheet metal forming. The primary objective is to use the deep drawing cup test to streamline FLC determination across a broader spectrum of strain states and, through the modification, to eliminate the influence of friction on the tested material. Furthermore, specific specimen geometries and dimensions are proposed to ensure the evaluation of the entire forming limit curve. The optimized specimen design allows for covering the full range of major and minor strains, from uniaxial tension through plane strain to near-uniform biaxial tension, with the additional capability of investigating multiple thicknesses on a single specimen. In this study, the test is applied to X5CrNi18-10 (1.4301) austenitic stainless steel. Validation of the methodology and the accuracy of the results are verified theoretically using Finite Element Method (FEM) numerical simulations and practically through experimental testing on the selected material with a thickness of 0.5 mm. During the experimental procedures, strains are recorded and evaluated using Digital Image Correlation (DIC). In this case, surface major and minor strain analysis is performed using only a single camera, which simplifies the evaluation process. For comprehensive validation, the results are compared with the well-established and standardized Nakajima method for FLC determination.

Sheet metal forming, Formability, FLC, Cupping test, Numerical simulation, DIC

Sheet metal forming, Formability, FLC, Cupping test, Numerical simulation, DIC

ŘIHÁČEK, J.; ZAKL, A.

30.05.2026

Springer-Verlag

International Journal of Advanced Manufacturing Technology

145

1-2

Spojené království Velké Británie a Severního Irska

793

809

17

https://link.springer.com/article/10.1007/s00170-026-18409-7