The effects of machining residual stresses on springback in deformation machining bending mode

Abstract

Hybrid machining-forming technology is a combination of two thin-structural machining and incremental forming manufacturing processes. A group of complex geometry parts in which a thick region is connected to a thin wall region can be manufactured through this technology with certain advantages. The parts made by this technology require less raw material compared to the ones created by means of machining. The major problem with this technology is the dimensional and geometric inaccuracy of its products which is mainly due to springback. The main purpose of this research was to study the effects of machining parameters and residual stresses induced by the machining primary stage on the subsequent springback after the forming stage. It was found by experiments that the parameters of cutting speed, axial depth of cut, mode of milling and milling path had a minor effect on springback. However, the workpiece fracture during the forming stage was observed to be sensitive to the prior machining feed rate. Both finite element simulations and experimental results confirmed that the compressive machining residual stresses increased with an increase in the machining feed rate. The compressive residual stresses postponed the onset of fracture at the workpiece lower end during the forming stage. Therefore, we could approach the forming tool closer to the bottom of the wall during forming and, as a result, springback decreased considerably.

Fatigue Testing Approach Utilising Machining Cutting Forces and Fixture Design

“…2 Fatigue testing using milling machine tool and designed fixture as the machining process progresses. Different areas of the specimen might experience tension or compression at different times, leading to a dynamic stress environment [23].This can reflect a scenario where structural components undergo complex stress cycles, not just uniform loading [24]. The change of the cutting direction can also change the induced stress (tension or compression).…”

Semi-Analytical Solution Model for Bending Deformation of T-Shaped Aviation Aluminium Alloy Components under Residual Stress

“…Aviation aluminium alloys, characterized by their lightweight properties and high specific strength, are extensively utilized in the aerospace sector [1]. Structures fabricated from aluminium alloy sheets, especially those of a thin-walled nature, are predominantly selected for aviation applications due to their capacity to enhance production efficiency, reduce product mass, shorten assembly durations, and decrease manufacturing expenses [2]. Nonetheless, these thin-walled aluminium alloy constructions routinely experience deformation post-manufacture.…”