The Upper Bound Theorem in Forging Processes: Model of Triangular Rigid Zones on Parts with Horizontal Symmetry

Abstract

This paper presents the analytical method capacity of the upper bound theorem, under modular approach, to extend its application possibilities. Traditionally, this method has been applied in forging processes, considering plane strain condition and parts with double symmetry configuration. However, in this study, the double symmetry is eliminated by means of a fluency plane whose position comes from the center of mass calculated. The study of the load required to ensure the plastic deformation will be focus on the profile of the part, independently on both sides of the fluence plane, modifying the number and the shape of the modules that form the two halves in which the part is defined. This way, it is possible to calculate the necessary load to cause the plastic deformation, whatever its geometric profile.

A Review on the Adiabatic Shear Banding Mechanism in Metals and Alloys Considering Microstructural Characteristics, Morphology and Fracture

“…In forging processes, Tresca [18] first reported the appearance of shear bands through X-shaped single or multiple patterns along the workpiece cross-section, also describing them as heat zones due to the intense temperature rise caused by severe shear localization. On many occasions, ABSs follow the trajectories of slip lines during the deformation progress, affecting the forging force as supported by the Upper Bound Method (UBM) [19]. Semiatin and Lahoti [20] studied ASB formation in the hot forging of the Ti-6242 alloy, introducing a flow localization parameter for ASB initiation and suggesting that ASBs start to manifest as X-shaped bands.…”

Special Issue of the Manufacturing Engineering Society 2020 (SIMES-2020)

“…Regarding the specific contributions of the Special Issue in the journal Applied Sciences, 14 papers about cutting-edge advances in different fields of manufacturing engineering have been finally published after a rigorous review process. In particular, in: advances and innovations in manufacturing processes [6]; additive manufacturing and 3D printing [7]; manufacturing of new materials [8]; Product Lifecycle Management (PLM) technologies [9,10]; robotics, mechatronics and manufacturing automation [11]; Industry 4.0 [12,13]; design, modeling and simulation in manufacturing engineering [14,15]; and manufacturing engineering and society [16][17][18]; production planning [19]. Figure 2 shows the main topics and their percentages in this journal.…”

“…The topic "Design, modeling and simulation in manufacturing engineering" also collects two papers in different fields. David et al [14] study the influence of packaging design and placement at the point sale as some particular aspects of industrial design and their implications for society; and Martín et al [15] have developed a model of triangular rigid zones on parts with horizontal symmetry as an application of the upper bound theorem to the analysis of forging processes.…”