Your Selections

Zdravkovic, Srecko
Show Only


File Formats

Content Types








   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental and Analytical Study of Drawbead Restraining Force for Sheet Metal Drawing Operations

Oakland University-Natalia Reinberg, Ashutosh Mokashi, Saeid Nasheralahkami, Sergey Golovashchenko, Srecko Zdravkovic, Yurdaer Demiralp
  • Technical Paper
  • 2020-01-0753
To be published on 2020-04-14 by SAE International in United States
Design of sheet metal drawing processes requires accurate information about the distribution of restraining forces, which is usually accomplished by a set of drawbeads positioned along the perimeter of the die cavity. This study is targeting bringing together the results of finite element analysis and experimental data in order to understand the most critical factors influencing the restraining force. The experimental study of the restraining force was performed using drawbead simulator tool installed into a tensile testing machine. Based upon the experimental results, it was observed that the restraining force of the given drawbead configuration is dependent upon the depth of bead penetration, friction between the drawbead surfaces as well as the clearance between the flanges of the drawbead simulator. This clearance is often adjusted during stamping operations to increase or decrease material inflow into the die cavity without any modification in the die. Numerical simulation was performed with Autoform software following the geometry of the experimental drawbead tools used in this study. Two different surface conditions were used in the experimental tools: surface treatment…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Analysis of Sheet Metal Joining with Self-Piercing Riveting

Oakland University-Srecko Zdravkovic, Sergey Golovashchenko
  • Technical Paper
  • 2020-01-0223
To be published on 2020-04-14 by SAE International in United States
Self-piercing riveting (SPR) has been used in production to join sheet materials since the early 1990s. A large amount of experimental trial work was required in order to determine an appropriate combination of rivet and anvil design to fulfill the required joint parameters. The presented study is describing the methodology of SPR joint design based on numerical simulation and experimental methods of defining required simulation input parameters. The required inputs are the stress-strain curves of sheet materials and rivets for the range of strains taking place in the SPR joining process, parameters required for a fracture model for all involved materials, and friction parameters for all interfaces of SPR process. In the current study, the normalized Cockroft-Latham fracture criterion was used for predicting fracture. Custom hole and tube expansion tests were used for predicting fracture of the riveted materials and the rivet, respectively. In order to define the flow curve for riveted sheets, the multistep rolling-tensile testing procedure was used. The multistep cylinder compression test was employed to define the flow curve for the rivet…