Relationship between mechanical properties and geometric parameters to limitation condition of springback based on springback-radius concept in V-die bending process

The determination of the accuracy of part geometry is based on the precise prediction of the springback-radius in sheet bending. Incorporating strength ratio, normal anisotropy, the strain-hardening exponent, and the geometric ratio, a simplified model is proposed to predict the springback-radius in V-die bending based on elementary bending theory. Experiments were conducted to validate the derived equation based on the proposed modeling for this radius. The calculation of springback-radius agrees closely with the experimental results, proving the reliability of the present model. To reduce springback and achieve the correct radius of bent parts in the sheet bending process, the effects of process parameters, including punch radius, material strength and sheet thickness, on springback-radius ratio (punch radius divided by the radius of bending after unloading) were experimentally examined to identify those that govern springback variations for a high-strength steel sheet. The manner in which the strength ratio (material constant divided by elastic constant), normal anisotropy, strain-hardening exponent, and geometric ratio (sheet thickness divided by punch diameter) affect springback-radius in the V-die bending process for high-strength steel sheet is theoretically examined. Finally, a relationship between mechanical properties and geometric parameters to limitation condition of springback based on springback-radius concept in V-die bending process is examined. The goal is to improve the accuracy of the springback-radius after unloading in the V-die bending process.