فهرست نشریات علمی دسترسی آزاد ایران

Workability is a measure of the extent of deformation that a material can withstand before failure in bulk forming processes. In these processes, ductile fracture is the most common failure mode. In this study, ring expansion tests with a stepped conical punch were performed on samples with different geometries. For each strain path, axial and circumferential strains were calculated, and the right side of workability diagram was extracted. The primary objective of this paper is to determine the workability of C22000 alloy by fracture in mode I of fracture mechanics, which involves crack opening by tension. This study is the first, to the authors' knowledge, to simultaneously determine the right side of the workability diagram using anisotropic ductile damage mechanics. The formulation was developed within the framework of thermodynamics of irreversible processes, and a symmetric second-order tensor was used to describe the anisotropic damage state variable. The model was implemented using VUMAT coding and ABAQUS/Explicit software to simulate experimental tests. In order to display the workability diagram numerically, the adopted approach is based on the determination of damage values. Previous strain measurements were made just before crack initiation, and thus, with this method, the extraction of the diagram is done more comprehensively. The results show that different levels of damage and damage evolution can represent distinct regions of the workability diagram.