Abstracts: Components press formed from layered or laminated metallic materials have Wide engineering application in aerospace, automobile, electrical, electronic and process industries. High strength ferrous material grades are widely used in automobile and aerospace application for improving strength to weight ratio. Forming of high strength material is difficult. Formability of high strength ferrous material can be improved by applying the layering of the higher formability materials. But to fabricate the layered\laminated blanks it-self is challenging issue. Further, metal forming mechanics of layered or laminated materials is complex to understand and under the circumstances, development of analytical models for studying and analyzing the forming mechanics of such materials is difficult. The aim of this study is to investigate the bending characteristics such as sheet thickness change and the bending angles of the sheet before/after springback. Share of high and advanced high strenght steels in automobile is increasing , however such a steel generally have a poor formability and high amount of springback because of discussed phenomena, it becomes difficult to control the dimension of the final product obtained using bending/forming. In this study, the results of analytical and experimental are compare with each other. According to that comparision, we will analyze the springback effect with bilayerd material (SS-304 and AL-6101T6) having combination of different dimensions.
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.