Vyhodnocení tvářitelnosti plechů pomocí tvarových zkušebních těles

Abstract

The diploma thesis deals with tests of the formability of sheet materials using shaped test bars. The work is divided into several chapters, where the introductory chapter presents the forming of sheets and the evaluation of their formability, including factors, methods and technological connections influencing their deformation behavior and use in practice. The next chapter presents methods for evaluating the formability of thin sheets, diagrams of limit deformations, methods of creating and measuring deformation networks, followed by a description of the device for cutting test samples, a description of the hydraulic press and the method of using the device. Furthermore, the cutting of test bars for tensile testing and the subsequent determination of mechanical properties, the coefficient of plastic anisotropy and the exponent of strain hardening and cutting of test bars with side cuts are presented. This is followed by the determination of mechanical properties, the plastic anisotropy coefficient and the strain hardening exponent using bars intended for tensile testing according to the standards ČSN EN ISO 6892-1, ČSN ISO 10113 and ČSN ISO 10275, and then the determination of the ultimate deformation curve in the left part of the ultimate deformation diagram using bars with side cuts.