Part accuracy improvement in two point incremental forming with a partial die using a model predictive control algorithm

Abstract

.Part accuracy improvement in two point incremental forming with a partial die using a model predictive control algorithm.Precision Engineering http://dx.doi.org/10. 1016/j.precisioneng.2017.02.006 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Research highlights: Flexible forming technologies are becoming increasingly significant with the rise of small batch and customised production in the market. work. The enhanced control algorithm is able to correct the toolpath in both the vertical and horizontal directions. In the newly-added horizontal control module, intensive profile points in the evenly distributed radial directions of the horizontal section were used to estimate the horizontal error distribution along the horizontal sectional profile during the forming process. The toolpath correction was performed through properly adjusting the toolpath in two directions based on the optimised toolpath parameters at each step. A case study for forming a non-axisymmetric shape was conducted to experimentally validate the developed toolpath correction strategy. Experiment results indicate that the two-directional toolpath correction approach contributes to part accuracy improvement in TPIF compared with the typical TPIF process that is without toolpath correction.

Adjusting residual stresses by flexible stress superposition in incremental sheet metal forming

“…The TPIF process ( Fig. 1b) developed by Matsubara [5] can improve the geometric accuracy of the manufactured components by using supporting dies [6]. By using dedicated solid dies, the TPIF process is less flexible than SPIF [7].…”

A Novel Approach to Predict Wrinkling of Aluminum Alloy During Warm/Hot Sheet Hydroforming Based on an Improved Yoshida Buckling Test

“…Besides the preferred orientation and the relative thickness (t/D) of sheet metal, wrinkling is related to the stress ratio of deformation, the mechanical properties of the material, the geometric shape of the die, and the contact conditions between workpiece and die [25,26]. However, it is difficult to take account of all of these factors in a theoretical model.…”

“…[9,12], wrinkling can still occur during sheet forming. To improve the precision and quality of forming of parts and effectively eliminate wrinkling instability, it is particularly important to obtain accurate predictions of the likelihood of wrinkling in the forming process [24][25][26]. Therefore, it is necessary to investigate the prediction of wrinkling of sheet metal during warm/hot hydroforming.…”

Research on the Radial Accuracy of Ultrasonic Vibration-Assisted Single Point Incremental Forming Parts

“…The defects were reduced by controlling the related parameters of the stress ratio. Based on the basic structure of a simple Model Predictive Control (MPC) algorithm designed for SPIF in previous work [7], an enhanced MPC algorithm had been developed especially for Two Point Incremental Forming (TPIF) with a partial die by Lu et al [8]. Radu et al [9] found that the accuracy error mainly comes from the springback of the part after the tool head and the holding device are unloaded.…”