Improving Formability in SPIF Processes through High Speed Rotating Tool: Experimental and Numerical Analysis

2013 ◽  
Vol 549 ◽  
pp. 156-163 ◽  
Author(s):  
Gianluca Buffa ◽  
Davide Campanella ◽  
Rossano Mirabile ◽  
Livan Fratini

Single-point incremental forming (SPIF) is a quite new sheet-forming process which offers the possibility to deform complex parts without dedicated dies using a single-point tool and a standard three-axis CNC machine. Although the process mechanics enables higher strains with respect to traditional sheet-forming processes, research has been focused on further increasing the maximum forming angle. In the paper, a new approach is used to enhance the material formability through a localized sheet heating as a consequence of the friction work caused by high speed rotating tool. Numerical simulation was utilized to relate the effect of temperature with the main field variables distribution in the sheet.

2019 ◽  
Vol 14 (2) ◽  
pp. 58-70
Author(s):  
Adil Shbeeb Jabber

Incremental sheet metal forming process is an advanced flexible manufacturing process to produce various 3D products without using dedicated tool as in conventional metal forming. There are a lot of process parameters that have effect on this process, studying the effect of some parameters on the strain distributions of the product over the length of deformation is the aim of this study. In order to achieve this goal, three factors (tool forming shape, feed rate and incremental step size) are examined depending on three levels on the strain distributions over the wall of the product. Strain measurement was accomplished by using image processing technique using MATALB program. The significance of the control factors are explored using two statistical methods:  analysis of variance (ANOVA) and main effect plot (MEP). All experiments were carried out on a sheet of Aluminum alloy (Al1050) with thickness 0.9 mm by using 3 axes CNC machine to produce frustum pyramid product. The result showed that the feed rate is a parameter that has large effect on the values of the effective strain percentage contribution of (42.86% and 51.42%), respectively, and is followed by step size (25.1% and 30.60%) percentage contributions and finally the tool shape with (21.79% and 10.54%) on the (55° and 45°) wall angle, respectively. The maximum and minimum average effective strain computed on the 55◦ forming angle were (0.580 and 0.399), respectively. Finally, the maximum and minimum average effective strain computed on the 45◦ forming angle were equal to (0.412 and 0.324), respectively.


2011 ◽  
Vol 473 ◽  
pp. 913-918 ◽  
Author(s):  
Gianluca Buffa ◽  
Giuseppe Ingarao ◽  
Livan Fratini ◽  
Fabrizio Micari

Single Point Incremental Forming (SPIF) is a quite new sheet forming process which offers the possibility to deform complex parts without dedicated dies using only a single point tool and a standard 3-axis CNC machine. The process mechanics enables strains much higher than traditional sheet forming processes, but particular attention must be given to the final part geometrical accuracy. In this paper the capabilities of a dedicated explicit numerical model are quantitatively analyzed on pyramid-shaped parts. In particular a comparison between experimental and numerical results is reported. Three different shapes at the varying of the stamping angle were considered and the final shape was acquired, through a white light triangulation based optical scanner, after the removing of the punch and of the clamping fixture. LS-DYNA commercial code was used to simulate the three different case studies, and an explicit loading-implicit unloading approach was implemented in order to simulate also the shape distortions due to springback phenomenon. The effect of several numerical parameters on the final shape and the thickness distribution were investigated. In particular numerical results were analyzed at the varying of the material constituve law, of the shell element type and of the number of integration points along the thickness.


2018 ◽  
Vol 19 (3) ◽  
pp. 313
Author(s):  
Masood Ghassabi ◽  
Milad Salimi ◽  
Mohammad Haghpanahi

Incremental forming is one of the most well-known forming processes for complex and asymmetric parts. This method uses a CNC machine, simple forming tool, and a die. This study focused on effects of some parameters such as the material, feed rate, pitch, rotational speed and movement strategy of tool on the dimensional precision, forming force, thickness distribution and fracture in the welding area. The results showed that single point incremental forming (SPIF) led to a better thickness distribution with lower tool force, whereas two-point incremental forming led to better dimensional accuracy. Rotational speed does not have any significant impact on the forming process while decreasing the feed rate partially reduced the forming force. According to the results, although dimensional precision in double point incremental forming is better than SPIF, when it comes to the thickness distribution, forming force, and economic issues, SPIF is in favor. The results also showed that by connecting two materials, different parameters for the two materials could be investigated simultaneously in one simulation process.


2018 ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann

Compared to the conventional single-point incremental forming (SPIF) processes, water jet incremental micro-forming (WJIMF) utilizes a high-speed and high-pressure water jet as a tool instead of a rigid round-tipped tool to fabricate thin shell micro objects. Thin foils were incrementally formed with micro-scale water jets on a specially designed testbed. In this paper, the effects on the water jet incremental micro-forming process with respect to several key process parameters, including water jet pressure, relative water jet diameter, sheet thickness, and feed rate, were experimentally studied using stainless steel foils. Experimental results indicate that feature geometry, especially depth, can be controlled by adjusting the processes parameters. The presented results and conclusions provide a foundation for future modeling work and the selection of process parameters to achieve high quality thin shell micro products.


2017 ◽  
Vol 749 ◽  
pp. 154-160
Author(s):  
Khanh Dien Le ◽  
Tan Hung Nguyen ◽  
Ngoc Huy Tran ◽  
Thanh Son Le ◽  
Huy Bich Nguyen ◽  
...  

Single Point Incremental Forming (SPIF) is a recent technology of forming sheet in several decades. Nowadays, SPIF technology is still continued to be studied, applied and ameliorated in sheet manufacturing in industry. However one of the difficulties of the technology is the forming angle is still small (smaller than 800 according the properties of metal sheets). This paper recommends a measure of increasing the plasticity of the sheet by heating in time of forming by SPIF technology. Naturally, the plasticity of metal sheet increases by the temperature of the material in forming process with its limitation and constraint. The paper represents the effect of heating metal sheet through the empirical process of SPIF technology directed by the design of experiment (DOE). The analyses of the results of experimental process is applied to show the effect of heating to the precision of Titanium sheet. Finally, some private opinions about the heating in SPIF are also mentioned as a very tiny contribution of the research for the new technology.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Mingshun Yang ◽  
Zimeng Yao ◽  
Yan Li ◽  
Pengyang Li ◽  
Fengkui Cui ◽  
...  

An excessive thickness-reducing ratio of the deformation zone in single point incremental forming of the metal sheet process has an important influence on the forming limit. Prediction of the deformation zone thickness is an important approach to control the thinning ratio. Taking the 1060 aluminum as the research object, the principle of thickness deformation in the single point incremental forming process was analyzed; the finite element model was established using ABAQUS. A formula with high accuracy to predict the deformation zone thickness was fitted with the simulation results, and the influences of process parameters, such as tool diameter, step down, feeding speed, sheet thickness, and forming angle, on thinning ratio were analyzed. The accuracy of the finite element simulation was verified by experiment. A method to control the thinning rate by changing the forming trajectory was proposed. The results showed that the obtained value by using the fitted formula is closer to the experimental results than that obtained by the sine theorem. The thinning rate of the deformation zone increases with the increase of tool diameter, forming angle, and sheet thickness and decreases with the increase of step down, while the feeding speed had no significant effect on the thinning ratio. The most important factor of the thinning ratio is the forming angle, and the thinning ratio can be effectively reduced by using the forming trajectory with a uniformly distributed pressing point.


2013 ◽  
Vol 554-557 ◽  
pp. 1419-1431 ◽  
Author(s):  
Daniel Fritzen ◽  
Anderson Daleffe ◽  
Jovani Castelan ◽  
Lirio Schaeffer

This work addresses through bibliographies and experiments the behavior of sheet brass 70/30 for Incremental Sheet Forming process - ISF, based on the parameters: wall angle (), step vertical (ΔZ) strategy and the way the tool. Experiments based on the method called Single Point Incremental Forming - SPIF. For execution of practical tests, we used the resources: software CAD / CAM, CNC machining center with three axles, matrix incremental, incremental forming tool and a device press sheets. Furthermore, measurement was made of the true deformation () and thickness (s1). Practical tests have shown that the spiral machining strategy yielded a greater wall angle, compared to the conventional strategy outline.


2021 ◽  
Author(s):  
Muhammad Jawad Afzal ◽  
Asif Israr ◽  
Muhammad Soban Akram ◽  
Abdul Muqeet

Abstract For rapid prototyping, design validation and small batch productions process with low tooling cost is preferred. Single Point Incremental Forming (SPIF) is a die-less sheet metal forming process which requires only low cost forming tool driven by CNC machine in a toolpath to form required geometry at room temperature from sheet blank clamped in a low cost and low stiffness clamping system. In this study, effect of process parameters such as tool radius, feed rate and lubrication are considered on the formability of the truncated profile of AISI 321 Variable Wall Geometry (VWA). Set parameters conditions with 2 level layers are optimized using numerical and statistical approach. Experimentation on the same setup is carried out by selecting the most, least and mid favorable solutions optimized on the basis of forming forces and stresses in the sheet. Geometrical accuracy, sheet thinning, and forming forces are compared analytically, numerically and experimentally addressing the inadequacy of analytically models for Variable Wall Angle Geometries.


Author(s):  
Hongjun Zeng ◽  
Alan Feinerman ◽  
Zhiliang Wan

We have developed a new approach to achieve a high-speed micromirror, which can rapidly tilt large angles with a low voltage and a compact footprint. In our approach we use a liquid metal drop with a low vapor pressure as the pivot, and the micromirror is tilted by an electrostatic torque. Micromirrors (1 mm x 1 mm) and the actuating circuit are microfabricated with a centralized wetting area surrounded by a non-wetting Parylene area to confine the drop. The frequency response curve shows that the mirror has 78V snap-down voltage and resonant frequency at 165Hz, and has a potential resonant frequency more than 3k Hz if the size of the mirror and liquid metal pivot is reduced. A micromirror with a liquid metal pivot is expected to have significantly higher reliability since a liquid drop does not suffer from mechanical fatigue. Due to the single point support, the micromirror can be tilted in an arbitrary direction, and the fabrication process is simpler than those required to create solid torsional weak links.


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