Springback Prediction of Dieless Forming of AZM120 Sheet Metal Based on Constitutive Model

Zijin Wu,Jinrong Wang,Yangdong Chen,Yuanyuan Wei,Jianhe Gao,Junjie Gong

doi:10.3390/met10060780

Zijin Wu, Jinrong Wang + Show 4 more

Open Access

https://doi.org/10.3390/met10060780

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Journal: Metals	Publication Date: Jun 11, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: Yangzhou University, Shenyang Machine Tool (China)

Abstract

Springback control is a key issue of the sheet-metal-forming process. In this paper, the mechanism of sheet-metal-forming along the folding trajectory of the computer numerical control (CNC) four-side automatic panel bender was studied, based on the bend-forming springback compensation theory of the power function material model. Firstly, the mechanical property of AZM120 sheet metal standard samples was tested. Then, a theoretical model of springback compensation under plane strain conditions was built, based on the constitutive relationship of the elastic or the elastic-plastic power hardening material. In addition, a sheet-metal-forming trajectory model was designed for sheet metal bending using the vector method. Finally, a laser tracker was used to acquire the folding trajectory, and then the reliability of the trajectory model was verified. On this basis, the influences of geometric and process parameters, such as sheet thickness, forming angle, and bending radius in springback control, were studied according to the theoretical formula and verified by experiments. The proposed method is generally applicable to operation conditions where the bending radius ranges between 1.5 and 6.0 mm and plate thickness ranges from 0.8 to 2.5 mm, and the achieved overall accuracy was more than 89%.

Highlights

Sheet-metal-forming nowadays is widely used in the aeronautical, automotive, mechanical and construction industries [1]
This study presented an analytical model, in which the relationship between the power
The study of the bending radius indicated theinto trend of theoretical and results function material model and the springback wasthat taken consideration, and theexperimental dieless forming istrajectory almost consistent

Summary

Introduction

Sheet-metal-forming nowadays is widely used in the aeronautical, automotive, mechanical and construction industries [1]. The manufacture of sheet metal is developing towards high flexibility and efficiency, and small batch and flexible-surface-forming technology [2]. In traditional die-stamping production, the die design cycle is longer and the manufacturing cost is higher, so it is urgent to develop a technology for forming surface-curved parts with high flexibility and precision in the field of plastic processing. The computer numerical control (CNC) automatic panel bender has the advantages of a short operation path, no overall turnover of workpiece, fast feeding speed, etc. It can realize complete automatic production, from lean manufacturing to mass production.

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