Flexible-bending of profiles and tubes of continuous varying radii

Li, Pengfei; Wang, Liyan; Li, Mingzhe

doi:10.1007/s00170-016-8885-9

Cited by 33 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As early as the 1980s, it was predicted that CNC programming would play an important role in the development of flexible manufacturing processes for sheet metal products [16]. Today it can be claimed that the predictions were true, as proved by the wide use of CNC techniques for sheet metal cutting [17] and bending [18], as well as for incremental forming products with non-developable surfaces [19]. At the same time it was thought that bulk forming processes such as forging, rolling and metal powder forming are considerably limited in terms of flexible manufacturing system implementation [16].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical and experimental study on forming preforms in a CNC skew rolling mill

Pater

Tomczak

Bulzak

et al. 2022

Archiv.Civ.Mech.Eng

View full text Add to dashboard Cite

This paper relates to a study on the formation of elongated preforms in a CNC skew rolling mill. First, a numerical analysis was performed to investigate forming processes for three different parts: a scraper, a connecting rod, and a hook. The shapes and dimensions of preforms were designed, and rolling and closed-died forging processes for producing these parts were simulated numerically. Distributions of temperature, effective strain and damage function were determined for rolled preforms. Loads and torques in the rolling process were measured. It was found that the forming process of preforms performed in a CNC skew rolling mill was characterized by relatively low force parameters in relation to the dimensions of formed parts. Numerical simulations of the forging process showed that all forged parts had the required shape, which indicates that the preforms were designed correctly. Following the numerical analysis, experiments were performed in which the preforms were rolled under laboratory conditions (in a scale of 1:2). Experimental results demonstrated that the rolled parts had no internal defects (cracks) and were characterized by high dimensional accuracy.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Fig 18. Rolling process of a hook preform conducted in a CNC rolling mill, and the distribution of temperature in the workpiece (in °C)…”

mentioning

confidence: 99%

Numerical and experimental study on forming preforms in a CNC skew rolling mill

Pater

Tomczak

Bulzak

et al. 2022

Archiv.Civ.Mech.Eng

View full text Add to dashboard Cite

show abstract

“…It was demonstrated that using a removable die in bending has a significant effect on reducing process defects. Li et al 15 by numerical and experimental study of free bending, showed that continuous bending with a maximum bending radius ratio of 1.7 can be made for tubes with symmetric and asymmetric cross-sections. The bending ratio was defined as a ratio of the bending radius to the outer diameter of the tube.…”

Section: Introductionmentioning

confidence: 99%

The effects of loading path on process parameters in the free tube forming process

Mosavi

Mazdak

Sheykholeslami

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part B:

View full text Add to dashboard Cite

The free bending method is the simplest method among the tube bending processes without the use of a die. Despite the simplicity of the process, there is no proper control over the geometrical tolerance of the product. The loading path or in other words the bearing movement mechanism is one of the effective factors on product geometry. In this paper, a finite element simulation has been carried out to investigate two different bearing movement time-paths (synchronous and asynchronous mechanisms); then, the results have been verified with experimental tests. The thickness distribution in different directions, ovality, bending radius, and applied forces on the bearing and the tube for both bearing movement mechanisms are the main results of this paper. The amplitude of thickness change in both mechanisms was equal. But there is a uniform trend in variation of thickness distribution in synchronous mechanisms. So, better geometrical quality of products is expected in this mechanism. On the other hand, because of uniform force distribution with tube movement in the bearing and tube, the stability of the asynchronous mechanism is higher than the synchronous mechanism.

show abstract

“…Based on this background, the free bending forming (FBF) technology was firstly proposed in Japan by Murata et al in 1990 [17], and the prototype of a free bending machine was developed in 1993 [18]. Without changing the bending die and re-clamping the target tube [3], the tubes [19], profiles [20], and wires [21] with bend-in-bends or with continuous varying radii even possibly also with twisting can be manufactured precisely and efficiently by free bending forming (FBF) technology [22,23].…”

Section: Introductionmentioning

confidence: 99%

“…Some researchers began to pay attention to the free bending process of hollow profile tubes. Deformation behaviors of the thin-walled rectangular tube and angle iron of continuous varying radii have been investigated by Cheng et al [20] and Li et al [21], respectively. Using the innovative torque superposed spatial (TSS) bending method, the bending behaviors of thin-walled profiles made from high-strength steels for a changing angle of the bending plane have been fully characterized by Hudovernik et al [29] based on the principle of a simplified cantilever beam model.…”

Section: Introductionmentioning

confidence: 99%

Deformation behavior of convolute thin-walled AA6061-T6 rectangular tubes manufactured by the free bending forming technology

Cheng

Zhao

El-Aty

et al. 2021

Int J Adv Manuf Technol

View full text Add to dashboard Cite

During manufacturing thin-walled tubes using free bending forming (FBF) technology, defects such as wrinkling, cracking, and cross-section distortion are easy to exist due to various forming parameters' direct and indirect influence, which seriously influences the forming quality of the rectangular tubes. Thus, in this study, the finite element (FE) modeling of thin-walled AA6061-T6 rectangular tubes manufactured by FBF technology was accomplished and verified through experimentation. Moreover, the influence of different parameters on the deformation behavior of the rectangular tubes was systematically investigated using FE modeling. The results showed that the maximum thickness changing rate and the cross-section distortion appeared once the bending die moved to the maximum eccentricity (U max ). Besides, with the increase of yield strength-Young's modulus ratio (σ s /E), thickness (t 0 ), fillet radius (R f ), clearance (Δc), friction coefficient (f), and chamfer radius of the guider (R c ), the thickness changing rate and the cross-section distortion decrease, while the bending radius enlarges simultaneously when the parameters are set within reasonable limits. Unlike the above parameters, with the improvement of the axial feeding speed (V f ), the thickness changing rate declines while the fluctuation of bending radius is not significant. Under the joint action of the axial force P L , the structural characterization of the rectangular tube and the dies of constraints, the thinning of the outer wall and the web distortion are inhibited, and the variation amplitude of them is much smaller than that of thickening of the inner wall and flange distortion during the free bending process.

show abstract

Flexible-bending of profiles and tubes of continuous varying radii

Cited by 33 publications

References 18 publications

Numerical and experimental study on forming preforms in a CNC skew rolling mill

Numerical and experimental study on forming preforms in a CNC skew rolling mill

The effects of loading path on process parameters in the free tube forming process

Deformation behavior of convolute thin-walled AA6061-T6 rectangular tubes manufactured by the free bending forming technology

Contact Info

Product

Resources

About