Viscous inner and outer pressure forming method of thin-walled tube and its application

Gao, T.; Liu, Yang; Wang, Zhongjin

doi:10.1007/s11595-015-1160-3

Cited by 6 publications

(2 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The non-uniform pressure can reduce defects. Some researchers applied the non-uniform pressure to eliminate the wrinkles [27]. If the pressure at the bottom of the wrinkle is larger than at the apex, the height of the wrinkle is decreased.…”

Section: Introductionmentioning

confidence: 99%

Effect of the non-uniform pressure on the deformation and instability of the sheet in flexible-die bulge forming

Wang,

Wang

2024

Preprint

View full text Add to dashboard Cite

In recent years, the application of non-uniform pressure in flexible-die forming, such as viscous pressure forming and magnetorheological pressure forming, has been utilized in manufacturing many thin-walled components. However, the non-uniform pressure is mainly applied to change the shape of the sheet. The effects of the non-uniform pressure on thickness reduction and fracture are still intricate. In this study, the mechanism of the non-uniform pressure to decrease thickness reduction and delay fracture instability in the bulge test is revealed. The non-uniform pressure changes the principal stresses, causing distinct deformation behaviors. There are two opposite effects on thickness reduction and fracture instability. If the pressure at the bulged pole decreases, the shape is more prolate, leading toa decreased average thickness and a decreased polar curvature. The thickness reduction tends to be severe, and the diffuse necking is easy to produce. If the pressure at the bulged pole increases, the shape is more oblate, leading to an increased strain gradient. The thickness reduction tends to be severe, and the localized necking is easy to produce. Characteristics of the pressure to decrease thickness reduction and delay instability are presented. Viscous pressure bulge tests are carried out. Experiment results of the shape, thickness uniformity, polar strain, and fracture verify the theory. The fracture strain increases by 5.6 % compared with the uniform pressure condition. This study proves that non-uniform pressure can promote sheet formability, indicating that non-uniform pressure has broad application prospects in sheet metal forming.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of the non-uniform pressure on the deformation and instability of the sheet in flexible-die bulge forming

Wang,

Wang

2024

Preprint

View full text Add to dashboard Cite

show abstract

“…In the forming of corrugated tubes, the wrinkles are induced due to the compressive stress. By increasing the pressure at the peak of the wrinkle, the wrinkle is eliminated [25]. In stamping the sheet, the non-uniform pressure can reduce the friction between the model and the sheet to decrease the thickness reduction and increase formability [26].…”

Section: Introductionmentioning

confidence: 99%

Mechanism and experimental verification of non-uniform pressure in viscous pressure forming

Wang,

2024

Preprint

Self Cite

View full text Add to dashboard Cite

The plastic deformation of the complex thin-walled components is not uniform. Applying a non-uniform load can decrease the thickness reduction and improve the thickness uniformity. In recent years, the application of non-uniform pressure to deform the sheet (such as magnetorheological pressure forming and viscous pressure forming) has attracted researchers’ attention. However, the characteristics of the non-uniform pressure have not been researched. Control of the non-uniform pressure in the forming process lacks theoretical support. In this study, the mechanism of the non-uniform pressure in the viscous pressure bulge test is investigated. The pressure-carrying medium, called viscous medium, is semi-solid and flowable. The inhomogeneous flow behavior of the medium produces non-uniform pressure when the maximum is at the bulged pole. The inhomogeneous deformation behavior of the medium produces non-uniform pressure when the minimum is at the bulged pole. The effects of flow and deformation are opposite. The non-uniform pressure function is derived, and the evolution of the pressure is presented. During forming, the viscosity of the medium increases with the pressure, so the effect of the flow behavior increases, and the pressure weight at the pole increases. Viscous pressure bulge tests are carried out to verify the theory. The gradient and evolution of the pressure can be controlled by the loading velocity and the property of the medium. The results provide theoretical guidance for the control of the pressure in viscous pressure forming, and the methodology is expected to analyze the non-uniform pressure in other flexible die forming processes.

show abstract

Investigation on feasibility and process of PEI sheet by viscous warm pressure forming

Gao

Liu

2016

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Viscous inner and outer pressure forming method of thin-walled tube and its application

Cited by 6 publications

References 10 publications

Effect of the non-uniform pressure on the deformation and instability of the sheet in flexible-die bulge forming

Effect of the non-uniform pressure on the deformation and instability of the sheet in flexible-die bulge forming

Mechanism and experimental verification of non-uniform pressure in viscous pressure forming

Investigation on feasibility and process of PEI sheet by viscous warm pressure forming

Contact Info

Product

Resources

About