Title: Multistage tool path strategy to produce hemispherical shape using single point incremental forming process

Authors: Ashish M. Gohil; Bharat A. Modi

Addresses: Mechanical Engineering Department, School of Engineering under Institute of Technology, Nirma University, Ahmedabad – 382481, India ' Mechanical Engineering Department, School of Engineering under Institute of Technology, Nirma University, Ahmedabad – 382481, India

Abstract: Single-stage toolpath strategies used in the single point incremental forming process are suffering the problems related to formability, geometric accuracy, and non-uniform thinning. A multistage forming strategy can be used to improve the same, however, it leads to the formation of protrusion defect due to rigid body translation. In this paper, the multistage toolpath strategy has been proposed to circumvent this issue for hemispherical shape which is difficult to produce using a single-stage forming strategy due to 90 tool entry angle at the base. The proposed strategy doesn't require the calculation of rigid body translation and produces the hemispherical shape without the formation of protrusion defect. Enhancement in formability using proposed multistage forming strategy, in terms of depth of forming, uniform strain distribution and thinning have been presented based on experimental and numerical investigation. The limiting value of percentage increase in surface area during the stage is found to be 30.

Keywords: ISF; incremental sheet forming; SPIF; single point incremental forming; multistage tool path; thinning band; strain distribution; rigid body translation; protrusion defect.

DOI: 10.1504/IJMMS.2021.121224

International Journal of Mechatronics and Manufacturing Systems, 2021 Vol.14 No.3/4, pp.181 - 201

Received: 12 Aug 2020
Accepted: 12 Feb 2021
Published online: 01 Mar 2022 *