Modeling Force Fluctuations in Incremental Sheet Forming

Author(s):  
Michael Prize ◽  
Douglas Bristow ◽  
Robert Landers

Abstract Incremental Sheet Forming (ISF) is a versatile manufacturing method in which a three-dimensional part is fabricated by progressively deforming a metal sheet. This is typically done via a robot with a single point tool following a defined trajectory. During this process a reaction force between the forming tool and sheet is generated. This force, denoted the forming force and defined as the force acting perpendicular to the sheet, has been modeled in several studies. Given a part with homogenous material, a fixed part geometry, and constant process parameters, these models predict the forming force will be constant. However, many studies have shown that this force fluctuates during the process. This paper augments the model by accounting for changes in process parameters due to robot geometric errors to describe these fluctuations. The model is experimentally validated, and the fluctuations of the forming force are reduced by 51% by modifying the tool path based on the identified robot geometric error.

Author(s):  
Shamik Basak ◽  
K Sajun Prasad ◽  
Amarjeet Mehto ◽  
Joy Bagchi ◽  
Y Shiva Ganesh ◽  
...  

Prototyping through incremental sheet forming is emerging as a latest trend in the manufacturing industries for fabricating personalized components according to customer requirement. In this study, a laboratory scale single-point incremental forming test setup was designed and fabricated to deform AA6061 sheet metal plastically. In addition, response surface methodology with Box–Behnken design technique was used to establish different regression models correlating input process parameters with mechanical responses such as angle of failure, part depth per unit time and surface roughness. Correspondingly, the regression models were implemented to optimize the input process parameters, and the predicted responses were successfully validated at the optimal conditions. It was observed that the predicted absolute error for angle of failure, part depth per unit time and surface roughness responses was approximately 0.9%, 4.4% and 6.3%, respectively, for the optimum parametric combination. Furthermore, the post-deformation responses from an optimized single point incremental forming truncated cone were correlated with microstructural evolution. It was observed that the peak hardness and highest areal surface roughness of 158 ± 9 HV and 1.943 μm, respectively, were found near to the pole of single-point incremental forming truncated cone, and the highest major plastic strain at this region was 0.80. During incremental forming, a significant increase in microhardness occurred due to grain refinement, whereas a substantial increase in the Brass and S texture component was responsible for the increase in the surface roughness.


2015 ◽  
Vol 639 ◽  
pp. 535-542 ◽  
Author(s):  
Bin Lu ◽  
Dong Kai Xu ◽  
Run Zhe Liu ◽  
Heng An Ou ◽  
Hui Long ◽  
...  

Incremental sheet forming (ISF) is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. Comparing to conventional sheet forming processes, ISF is of a clear advantage in manufacturing small batch or customized products such as cranial implant. Although effort on cranial reconstruction by using incremental sheet forming approach has been made in recent years, research has been mostly based on the single point incremental forming (SPIF) strategy and there are still considerable technical challenges for achieving better geometric accuracy, thickness distribution and complex cranial shape. In addition, the use of a backing plate or supporting die reduces the process flexibility and increases the cost. To overcome these limitations, double side incremental sheet forming (DSIF) process is employed for forming Grade 1 pure titanium sheet by using different toolpath strategies. The geometric accuracy and thickness distribution of the final part are evaluated so the optimized tool path strategies are developed. This leads to an assessment of the DSIF based approach for the application in cranial reconstruction.


2007 ◽  
pp. 233-250 ◽  
Author(s):  
M. Bambach ◽  
M. Cannamela ◽  
M. Azaouzi ◽  
G. Hirt ◽  
J.L. Batoz

2020 ◽  
Vol 44 (1) ◽  
pp. 148-160
Author(s):  
S. Pratheesh Kumar ◽  
S. Elangovan

Incremental sheet forming is a flexible and versatile process with a promising future in the batch production and prototyping sectors. With decreased design time and negligible production time, incremental sheet forming provides reliability, flexibility, and quality, while being an economical option in contrast to the traditional forming process. In this paper, Inconel 718, a material that has extensive use in aircraft engines, is considered for experimental work to obtain the optimum combination of process parameters. Response surface methodology is used to optimize the process parameters, in particular feed rate, step depth, and lubricant viscosity. The output responses are surface roughness, profile accuracy, and wall thickness. Analysis of variance (ANOVA) is performed using the experimental results to predict the statistical influence of the process parameters. The optimal combination of process parameters is further predicted using a numerical optimization technique to achieve better profile accuracy and surface finish. The results obtained are experimentally validated and are in good agreement with the predicted values.


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.


2007 ◽  
Author(s):  
P. Eyckens ◽  
S. He ◽  
A. Van Bael ◽  
P. Van Houtte ◽  
J. Duflou

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