Achieving maximum dimensional accuracy and surface quality at the shortest possible time in single-point incremental forming via multi-objective optimization

Author(s):  
Abolfazl Taherkhani ◽  
Ali Basti ◽  
Nader Nariman-Zadeh ◽  
Ali Jamali

Single-point incremental forming is a novel and flexible method for producing three-dimensional parts from metal sheets. Although single-point incremental forming is a suitable method for rapid prototyping of sheet metal components, there are limitations and challenges facing the commercialization of this process. Dimensional accuracy, surface quality, and production time are of vital importance in any manufacturing process. The present study is aimed at selecting proper forming parameters to produce sheet metal parts which possess dimensional accuracy and good surface quality at the shortest time. Four parameters (i.e. tool diameter, tool step depth, sheet thickness, and feed rate) are chosen as design variables. These parameters are used for the modeling of the process using Group Method of Data Handing(GMDH) artificial neural networks. The data necessary for establishing empirical models are obtained from single-point incremental forming experiments carried out on a computer numerical control milling machine using central composite design. After the evaluation of the model accuracy, single- and multi-objective optimization are performed via genetic algorithm. The performance of the design variables of a tradeoff point corresponding to one of the experiments shows the efficiency and accuracy of the models and the optimization process. Considering the priorities of objective functions, a designer will be able to set proper process parameters.

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Abdulmajeed Dabwan ◽  
Adham E. Ragab ◽  
Mohamed A. Saleh ◽  
Saqib Anwar ◽  
Atef M. Ghaleb ◽  
...  

Single-point incremental forming is an innovative flexible and inexpensive technique to form sheet products when prototypes or small batches are required. The process allows complex geometries to be produced using a computer numerical control machine, eliminating the need for a special die. This study reports on the effects of four important single-point incremental forming process parameters on produced surface profile accuracies. The profile accuracy was estimated by measuring the side angle errors and surface roughness and also waviness and circularity of the product inner surface. Full factorial design of experiments was used to plan the study, and the analysis of variance was used to analyze and interpret the results. The results indicate that the tool diameter (d), step depth (s), and sheet thickness (t) have significant effects on the produced profile accuracy, while the feed rate (f) is not significant. As a general rule, thin sheets with greater tool diameters yielded the best surface quality. The results also show that controlling all surface quality features is complex because of the contradicting effects of, and interactions between, a number of the process parameters.


2015 ◽  
Vol 651-653 ◽  
pp. 1078-1083 ◽  
Author(s):  
Henia Arfa ◽  
Riadh Bahloul ◽  
Hedi Belhadj Salah

Single Point Incremental Forming (SPIF) technology has been announced in the recentpast to manufacture sheet metal products by using Computer Numerical Control machines (CNC). Ithas been frequently used in different fields like the aeronautics. In incremental forming, materialsare submitted to permanent deformation by cold forming to produce a variety of three complicateddimensional shapes. The final form of the parts in sheet metal forming is highly affected by thespring-back and the pillow effect, occurring when the material is set free of the forming constraints.In this sense, the best solution is to adopt a process of multiobjective optimization in which a set ofnumerical simulations can be achieved on the basis of the box-Behnken experimental design. In thisway, the design variables are wall angle, initial thickness, tool diameter and incremental size. Tostudy the geometric characteristics, a cone-shaped part with circular base is considered. This paperaims to identify an overview of multiobjective design optimization of incremental metal formingparameters in order to minimize objective functions of pillow effect, springback and thinning ratesimultaneously. In an attempt to solve fitness functions, the method of Multiobjective GeneticAlgorithm (MOGA) is developed in this investigation. In this case, we should consider severalpoints of the appropriate process parameters which correspond to the best compromises with respectto several antagonistic objectives. As well as, a generation of the approximate Pareto optimalsolutions is presented in this study.


2018 ◽  
Vol 21 (1) ◽  
pp. 108 ◽  
Author(s):  
Aqeel Sabree Bedan ◽  
Halah Ali Habeeb

Incremental forming is a flexible sheet metal forming process which performed by utilizes simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. One limitations of single point incremental forming (SPIF) process is the error occur between the CAD design and the product profile. This work presents the single point incremental forming process for produced pyramid geometry and studied the effect of tool geometry, tool diameter, wall angle, and spindle speed on the dimensional accuracy. Three geometries of forming tools were used in experimental work: ball end tool, hemispherical tool, and flat with round corner tool. The sheet material used was pure Aluminum (Al 1050) with thickness of (0.9 mm). The experimental tests in this work were done on the computer numerical control (CNC) vertical milling machine. The products dimensions were measured by utilized the dimensional sensor measuring instrument. The extracted results from the single point incremental forming process indicated the best acceptance between the CAD profile and product profile was found with the ball end tool and diameter of (10 mm), wall angle (50°) and the rotational speed of the tool was (800 rpm).


Author(s):  
Abdulmajeed Dabwan ◽  
Adham E Ragab ◽  
Mohamed A Saleh ◽  
Atef M Ghaleb ◽  
Mohamed Z Ramadan ◽  
...  

Incremental sheet forming is a specific group of sheet forming methods that enable the manufacture of complex parts utilizing computer numerical control instead of specialized tools. It is an incredibly adaptable operation that involves minimal usage of sophisticated tools, dies, and forming presses. Besides its main application in the field of rapid prototyping, incremental sheet forming processes can be used for the manufacture of unique parts in small batches. The goal of this study is to broaden the knowledge of the deformation process in single-point incremental forming. This work studies the deformation behavior in single-point incremental forming by experimentally investigating the principal stresses, principal strains, and thinning of single-point incremental forming products. Conical-shaped components are fabricated using AA1050-H14 aluminum alloy at various combinations of fundamental variables. The factorial design is employed to plan the experimental study and analysis of variance is conducted to analyze the results. The grey relational analysis approach coupled with entropy weights is also implemented to identify optimum process variables for single-point incremental forming. The results show that the tool diameter has the greatest effect on the thinning of the SPIF product, followed by the sheet thickness, step size, and feed rate.


CIRP Annals ◽  
2005 ◽  
Vol 54 (2) ◽  
pp. 88-114 ◽  
Author(s):  
J. Jeswiet ◽  
F. Micari ◽  
G. Hirt ◽  
A. Bramley ◽  
J. Duflou ◽  
...  

2016 ◽  
Vol 19 (3) ◽  
Author(s):  
CRINA RADU ◽  
EUGEN HERGHELEGIU ◽  
ION CRISTEA ◽  
CAROL SCHNAKOVSZKY

<p>The aim of the current work was to analyse the influence of the process parameters (tool diameter, size of the vertical step of tool, feed rate and spindle speed) on the quality of the processed surface, expressed in terms of roughness and macrostructure in the case of parts processed by single point incremental forming. The analysis was made on A1050 aluminium metal sheets. The obtained results revealed that the process parameters influence differently the surface quality, the worst influence being exerted by the increase of the vertical step of tool. </p>


2015 ◽  
Vol 9 (1) ◽  
pp. 1025-1032
Author(s):  
Shi Pengtao ◽  
Li Yan ◽  
Yang Mingshun ◽  
Yao Zimeng

To furthermore optimize the machining parameters and improve the surface quality of the workpieces manufactured by single point incremental forming method, the formation mechanism of the sacle veins on the metal incremental froming workpieces was studied through experiment method. The influence principle of the spindle speed, the feed speed and the material of tip of tools on the length of scale veins was obtained through analyzing the experimental results and building the mathematical model among the length of scale veins were feed speed and spindle speed through measuring the roughness of surfaces and observing the appearance of the forming workpieces. The experimental results showed that, the spindle speed, the feed speed and the material of tool tips have a significant effect on the scale veins formation on the surface of forming workpieces. Therefore, an appropriate group of spindle speed and feed speed can reduce the effect of scale veins on the roughness of single point incremental forming workpieces and furthermore improve the surface quality of forming workpieces.


2021 ◽  
Vol 343 ◽  
pp. 04007
Author(s):  
Mihai Popp ◽  
Gabriela Rusu ◽  
Sever-Gabriel Racz ◽  
Valentin Oleksik

Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final geometrical accuracy of the parts manufactured through single point incremental forming.


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