13-09-2017, 09:47 AM
Precise springback prediction is a key to assessing the accuracy of part geometry in leaf flexion. A simplified approach is developed considering the thickness ratio, normal anisotropy and the strain hardening exponent to estimate the elastic recovery of vein flexion based on the elemental flexion theory. Consequently, a series of experiments is performed to verify the numerical simulation. The calculation of the spring angle corresponds well with the experiment, which reflects the reliability of the proposed model. The effects of process parameters such as punch radius, material strength and blade thickness at the spring angle are experimentally tested to determine the key parameters for reducing the spring angle in the sheet bending process high strength steel. In addition, the effects of the thickness ratio, normal anisotropy and the strain hardening exponent on the spring angle are studied theoretically in the process of folding of veins for high strength steel sheets. Therefore, it is possible to improve the understanding and control of the reduction of the spring of the folding process in practical applications.
New analyzes of finite elements and a series of experiments are carried out to characterize high-strength sheet metal parts manufactured by asymmetric V-shaped die matrices. The proposed strategy uses a finite element analysis of elasticity-plasticity to simulate the asymmetric V-matrix bending process and to test its viability for frictional contact processes. Consequently, a series of experiments got a good agreement with the numerical simulation. The effects of the process parameters (eg lubrication (contact friction), material properties and process geometries) in the deflection at the bending point were experimentally tested to identify the main parameters of the position deviation in the processes of sheet bending. In addition, the effects of the spring phenomenon on bending defects and on the accuracy of an asymmetric bent component are discussed. The results of this study can be considered when developing process design guidelines for asymmetric processes in high strength steel sheets.
New analyzes of finite elements and a series of experiments are carried out to characterize high-strength sheet metal parts manufactured by asymmetric V-shaped die matrices. The proposed strategy uses a finite element analysis of elasticity-plasticity to simulate the asymmetric V-matrix bending process and to test its viability for frictional contact processes. Consequently, a series of experiments got a good agreement with the numerical simulation. The effects of the process parameters (eg lubrication (contact friction), material properties and process geometries) in the deflection at the bending point were experimentally tested to identify the main parameters of the position deviation in the processes of sheet bending. In addition, the effects of the spring phenomenon on bending defects and on the accuracy of an asymmetric bent component are discussed. The results of this study can be considered when developing process design guidelines for asymmetric processes in high strength steel sheets.