Numerical investigation of multi-point forming process for sheet metal: wrinkling, dimpling and springback

Cai, Zhongyi; Wang, Shaohui; Li, Mingzhe

doi:10.1007/s00170-007-1045-5

Cited by 80 publications

(31 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A small radius of curvature will lead to large bending deformation, combined with plane stress as the sheet surface tries to contract under the pins. This leads to stress instability and wrinkling [3]. Small pins (less than 12.5 mm) or large pins (more than 17.5 mm) will increase wrinkling.…”

Section: Design Of Experimentsmentioning

confidence: 99%

“…The process is flexible to accommodate rapid changes in product design without affecting tooling costs. Many investigations have been conducted to develop the MPF technique [1][2][3][4]. Walczyk and Hardt [1] reviewed MPF die design techniques, which include construction of the die model, clamping of the pin matrix, containment frame and load capacity.…”

Section: Introductionmentioning

confidence: 99%

“…Qian et al [2] reported that complex shapes such as satellite heads can be fabricated using MPF. Cia et al [3] investigated the effect of the contact points between the pins and sheet on process defects, such as dimpling, wrinkling and spring back. The effect of forming force and mesh size on these defects was also investigated.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optimisation of multi-point forming process parameters

Abosaf

Essa

Alghawail

et al. 2017

Int J Adv Manuf Technol

View full text Add to dashboard Cite

The need for sheet metal forming using reconfigurable dies has increased due to rapid changes in part design to meet customer requirements, especially in the automotive industry. Reconfigurable dies have relatively low manufacturing cost compared with solid dies, and the same tool can be readily changed to produce different parts. Previous investigations have focused on avoiding defects without taking into account the effects of process on the quality characteristics of fabricated parts. This study investigated the influence of parameters, such as the elastic cushion thickness, coefficient of friction, pin size and radius of curvature, on the quality of parts formed in a flexible multi-point stamping die. The aim was to determine the optimum values of those parameters. Finite element modelling was employed to simulate the multi-point forming of hemispherical parts. Using the response surface method, the effects of process parameters on wrinkling, deviation from the target shape and thickness variation were investigated and the process parameters yielding the best product quality characteristics were obtained. The results show that pin size and radius of curvature have the greatest influence on wrinkling and deviation between formed and target shapes, while coefficient of friction, pin size and radius of curvature significantly affect thickness variation.

show abstract

Section: Design Of Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optimisation of multi-point forming process parameters

Abosaf

Essa

Alghawail

et al. 2017

Int J Adv Manuf Technol

View full text Add to dashboard Cite

show abstract

“…Elastic cushion technology can be used to suppress dimples commendably [7,8], but it also influences precision of formed workpiece. Especially for hyperbolicity workpiece, the influence of elastic cushion and spring back upon precision is not identic in X and Y direction.…”

Section: Introductionmentioning

confidence: 99%

Untitled

Zhang¹,

Liu²,

Fu³

2015

Proceedings of the 2015 6th International Conference on Manufacturing Science and Engineering

View full text Add to dashboard Cite

Abstract. A finite element model was built for the sheet metal multi-point stretch forming (MPSF), and the numerical simulation of the MPSF for the saddle and spherical surface workpiece were performed. The simulation results show that，to hyperbolicity workpiece, the influence on precision is different in dissimilar direction, and the reason was analysed. Besides，In MPSF, the contact between sheet and punches group is discontinuous, so it is very important to structure the enveloping surface of punch group. In this paper, four boundary line method was used to describe it to obtain smooth curved face, and B-spline curve was adopted to approach curves in four boundary line method. Finally, the experiment was done to approve the validity of method.

show abstract

“…A survey analysis revealed that a single reconfigurable die could replace hundreds of fixed tools that are currently in use [15]. In MPF, plenty of studies and progresses were made in recent years [18][19][20][21][22][23][24]. The MPF have been successfully applied in forming of the high-speed train body panel, ship hull plate, cranial titanium, and the lager crankle steel parts in architectures.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation on the local stress and local deformation in multi-point stretch forming process

Wang

Cai

et al. 2011

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Multi-point stretch forming (MPSF) is a new flexible forming technique to form aircraft outer skin parts. The multi-point stretching die (MPSD) replaces the traditional fixed shape stretching die, and the sheet metal is formed over a MPSD composed by the punch element. The MPSD is a discontinuous surface of discrete stretching die, and the stress concentration and local strain occur on formed parts. These lead to generate dimples on the surface of formed part. In this paper, a series of numerical simulations on MPSF processes for stretching parabolic cylindrical, spherical, and saddle-shaped parts were carried out. The local stress and local strain in thickness distribution of MPSF part were analyzed by dispersed the blank into solid elements. The forming results of MPSF were compared with those that use traditional stretch forming, and the influences of thickness of elastic cushion and the size of punch element on the stress concentration and local strain were surveyed. The simulation results show the distribution of local stress and local deformation in different layers, and the elastic cushion and the small size of punch element can reduce the stress concentration and local deformation. The results may understand the stress distribution on the sheet and prevent the defect of dimple.

show abstract

Numerical investigation of multi-point forming process for sheet metal: wrinkling, dimpling and springback

Cited by 80 publications

References 13 publications

Optimisation of multi-point forming process parameters

Optimisation of multi-point forming process parameters

Untitled

Numerical simulation on the local stress and local deformation in multi-point stretch forming process

Contact Info

Product

Resources

About