scholarly journals Radial Basis Functional Model of Multi-Point Dieless Forming Process for Springback Reduction and Compensation

Metals ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 528 ◽  
Author(s):  
Misganaw Abebe ◽  
Jun-Seok Yoon ◽  
Beom-Soo Kang
Keyword(s):  
Functional Model ◽  
Forming Process ◽  
Radial Basis ◽  
Dieless Forming ◽  
Springback Reduction

Experimental Investigation of a Backing Sheet Stiffener in Incremental Forming of Polycarbonate

2019 ◽  
Author(s):  
Tyler J. Grimm ◽  
Shubhamkar Kulkarni ◽  
Laine Mears ◽  
Gregory Mocko
Keyword(s):  
Incremental Forming ◽  
Elastic Recovery ◽  
Single Point ◽  
Plate Thickness ◽  
Steel Plates ◽  
Forming Process ◽  
Geometrical Accuracy ◽  
Backing Plate ◽  
Reduction Methods ◽  
Dieless Forming

Abstract Single point incremental forming (SPIF) is a dieless forming process for sheet materials. This process forms materials with a hemispherical forming tool which locally deforms the sheet at incremental depths. The freeform nature of this process promises significant efficiency improvements within small and medium volume industries where stamping is traditionally used. However, several drawbacks currently inhibit its widespread use. One of these drawbacks is springback or elastic recovery resulting in reduced geometrical accuracy. An existing approach to counter this involves using a dedicated backing die, increasing the cost of the forming apparatus and the overall energy input per part. Other springback reduction methods involve the direct addition of energy to the workpiece through electrical or heat input. This study investigates the use of sacrificial steel blanks as backing dies for incremental forming of polycarbonate sheets, to overcome the loss in geometrical accuracy affiliated with forming geometries with a relatively large distance between the geometry periphery and the clamped edge. The blanks were not bound to each other, but rather clamped along their edges. In this study, polycarbonate blanks were tested using a three-factorial design of experiments, with relative plate thicknesses of 0.4, 0.5, and 0.6, and wall angles of 15°, 30°, 45°, and 60° as independent factors. The test geometry used was a straight walled pyramid with a square base. Using the backing sheet, a reduction in the springback was observed, demonstrating the effectiveness of sacrificial backing blanks. Particularly, the ‘pillow effect’ at the base of the geometry was reduced. This is attributed to the higher stiffness of the steel plates, increasing the plastic strain on the polycarbonate. However, the formability is found to decrease for higher values of the backing plate thickness due to premature steel failure. In future studies, this work will be expanded to include additional thickness ratios, geometries, toolpath types, step sizes and materials to form a more complete trend.

Radial basis functional model for multi-objective sheet metal forming optimization

2011 ◽  
Vol 43 (12) ◽  
pp. 1351-1366 ◽  
Author(s):  
Guangyong Sun ◽  
Guangyao Li ◽  
Zhihui Gong ◽  
Guanqiang He ◽  
Qing Li
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Functional Model ◽  
Multi Objective ◽  
Radial Basis

Electrically Assisted Global Springback Elimination After Single Point Incremental Forming

2016 ◽  
Author(s):  
Trey Neveux ◽  
Brandt J. Ruszkiewicz ◽  
Tyler Grimm ◽  
John T. Roth ◽  
Ihab Ragai
Keyword(s):  
Residual Stress ◽  
Electric Current ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Appreciable Effect ◽  
Forming Process ◽  
Milling Operations ◽  
Path Testing ◽  
Springback Reduction

There has been a push in the automotive and aerospace industries towards die-less forming processing that are able to reduce both part cost and part energy. Incremental forming is a die-less forming process that fabricates parts using hemispherical tools following a tool path (similar to that found with conventional milling operations), that slowly deforms the sheet metal into the final desired configuration. Global springback for incremental forming, as defined herein, occurs after the part is unclamped from the retaining fixture. This form of springback is currently a significant impediment to the process since, when the part is released, the residual stresses created during the forming process result in significant part distortion and thereby, undesirable part geometries. To reduce this issue, this paper examines the effect on direct electric current on residual stress and springback elimination when applied post forming, which previous work has shown the potential to reduce this issue. This work is an extension of previous work resented at MSEC 2015. The previous work examined applying electric current to areas of high residual stress through the material’s thickness. This work examines the effect of applying electric current along the length and width of a part (path testing). This work concludes that running multiple paths increases springback reduction and the order in which the path testing is conducted has very little appreciable effect on the springback reduction during path testing.

scholarly journals A Mixed Double-Sided Incremental Forming Toolpath Strategy for Improved Geometric Accuracy

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Zixuan Zhang ◽  
Huaqing Ren ◽  
Rui Xu ◽  
Newell Moser ◽  
Jacob Smith ◽  
...  
Keyword(s):  
Incremental Forming ◽  
Sheet Forming ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Process Flexibility ◽  
Tool Positioning ◽  
Toolpath Planning ◽  
Forming Parameters ◽  
Planning Strategies ◽  
Dieless Forming

Double-sided incremental forming (DSIF) is a relatively new dieless forming process which uses two hemispherical ended tools, one on each side of the sheet, moving along a predefined trajectory to locally deform a peripherally clamped sheet of metal. DSIF provides greater process flexibility, higher formability, and eliminates the tooling cost when compared to conventional sheet forming processes. While DSIF provides much improved geometric accuracy compared to other incremental forming processes, current toolpath planning strategies suffer from long forming times. A novel mixed double-sided incremental forming (MDSIF) toolpath strategy is proposed in the present study. It simultaneously reduces the total forming time by half while preserving the best currently achievable geometric accuracy. The effect of the forming parameters, i.e., of the incremental depth and of tool positioning on the geometric accuracy of the parts formed with MDSIF was investigated and compared to those formed by traditional DSIF strategies.

A New Incremental Sheet Forming Process Based on Layer Manufacture

2014 ◽  
Vol 607 ◽  
pp. 124-127
Author(s):  
Jie Liu
Keyword(s):  
Sheet Metal ◽  
Metal Layer ◽  
Three Dimensional ◽  
Rapid Prototype ◽  
Layer By Layer ◽  
Forming Process ◽  
Rapid Prototype Technology ◽  
Nc System ◽  
Forming Technology ◽  
Dieless Forming

Sheet dieless digital forming is a new sheet metal dieless forming technology. This paper introduced the fundamentals of the Sheet dieless digital forming process. Based on the principle of “layered manufacture” in rapid prototype technology, this process resolves the intricate three-dimensional geometry information of the workpiece into a series of two-dimensional data, which can be used by an NC system to control a forming tool to make a curvilinear movement over the raw sheet metal layer by layer until the component wanted is formed. This paper introduced the Sheet dieless digital forming system and metal digital forming technology.

Numerical Determination of Unconstrained Area Effect on Springback in Incremental Forming of 5052-H32 Aluminum

2019 ◽  
Author(s):  
Tyler J. Grimm ◽  
Laine Mears
Keyword(s):  
Energy Savings ◽  
Incremental Forming ◽  
Sheet Material ◽  
Spring Back ◽  
Forming Process ◽  
Reduction Methods ◽  
Dieless Forming ◽  
Material Forming ◽  
Time And Energy

Abstract Incremental forming (IF) is a novel sheet material forming process which promises significant energy savings within the low and medium volume sheet production industries. This advantage stems from IF’s dieless forming nature, which alleviates the need for time and energy input towards die fabrication and offers significantly greater flexibility. However, a distinct disadvantage of this process is its relatively low forming rate compared to conventional stamping, which reduces its feasibility of use in higher volume productions. Springback is one disadvantage of incremental forming which has hindered its implementation within industry. Spring-back reduction methods, as well as springback characterization, can be found throughout literature. However, very few publications disclose the clamping dimensions used for fixturing work-pieces. This study numerically determines the springback effect of utilizing various clamping structures and presents an empirical solution for determining the springback of truncated pyramid geometries for various constraining areas. The resulting equation was found to have an acceptable degree of error relative to experimental analysis.

Optimization of waste combinations during in-vessel composting of agricultural waste

2016 ◽  
Vol 35 (1) ◽  
pp. 101-109 ◽  
Author(s):  
V Sudharsan Varma ◽  
Ajay S Kalamdhad ◽  
Bimlesh Kumar
Keyword(s):  
Agricultural Waste ◽  
Functional Model ◽  
Oxygen Demand ◽  
Waste Materials ◽  
Coefficient Of Determination ◽  
Cow Dung ◽  
Vegetable Waste ◽  
Radial Basis ◽  
Input Variables ◽  
Rotary Drum Composter

In-vessel composting of agricultural waste is a well-described approach for stabilization of compost within a short time period. Although composting studies have shown the different combinations of waste materials for producing good quality compost, studies of the particular ratio of the waste materials in the mix are still limited. In the present study, composting was conducted with a combination of vegetable waste, cow dung, sawdust and dry leaves using a 550 L rotary drum composter. Application of a radial basis functional neural network was used to simulate the composting process. The model utilizes physico-chemical parameters with different waste materials as input variables and three output variables: volatile solids, soluble biochemical oxygen demand and carbon dioxide evolution. For the selected model, the coefficient of determination reached the high value of 0.997. The complicated interaction of agricultural waste components during composting makes it a nonlinear problem so it is difficult to find the optimal waste combinations for producing quality compost. Optimization of a trained radial basis functional model has yielded the optimal proportion as 62 kg, 17 kg and 9 kg for vegetable waste, cow dung and sawdust, respectively. The results showed that the predictive radial basis functional model described for drum composting of agricultural waste was well suited for organic matter degradation and can be successfully applied.

Profile Correction of a Stretch Formed Aluminium Alloy during Artificial Ageing

2013 ◽  
Vol 549 ◽  
pp. 213-219 ◽  
Author(s):  
Gregor Volk ◽  
Alan G. Leacock ◽  
Desmond Brown
Keyword(s):  
Aluminium Alloy ◽  
Artificial Ageing ◽  
Natural Ageing ◽  
Stretch Forming ◽  
Forming Process ◽  
Heat Treated ◽  
Profile Correction ◽  
Commercial Aluminium ◽  
Springback Reduction ◽  
Creep Age Forming

A method of springback reduction is presented which involves a combination of solution heat treatment, natural ageing, stretch forming and artificial ageing. A commercial aluminium alloy, 2219-O Hi-Form, is solution heat treated and subjected to two pre-form natural ageing periods of one and seven hours before the stretch forming process. Following the forming process an artificial ageing process combined with creep age forming techniques is used. Springback is assessed following the stretch forming and artificial ageing processes. This process is shown to provide a controlled means of correcting the springback following stretch forming.

Real-Time Monitoring System of Dieless Bellows Forming Using Machine Vision

2013 ◽  
Vol 789 ◽  
pp. 429-435 ◽  
Author(s):  
Sugeng Supriadi ◽  
Tsuyoshi Furushima ◽  
Kenichi Manabe
Keyword(s):  
Image Processing ◽  
Machine Vision ◽  
Real Time ◽  
Local Heating ◽  
Image Processing Technique ◽  
Speed Ratio ◽  
Real Time Monitoring ◽  
Forming Process ◽  
Flexible Forming ◽  
Dieless Forming

Dieless bellows forming using local heating technique is an advanced flexible forming technology to produce bellows from straight tube without the use of dies. The deformation is induced by applying continuous compression, and local heating. Advantages of these processes are the absence of dies, applicability for various materials, suitability for flexible forming process including low batch production, flexibility on workpiece sizes and output geometries. However, the implementation of these processes is still low owing to the low quality, reproducibility, and production speed. The limitation of these dieless forming processes using local heating is caused by the absence of dies required to form the desired profile. Therefore deformation depends on temperature, length of heating zone, processing speed, speed ratio of feeding to fabrication speeds. In order to enhance the product quality in these dieless forming with local heating, real-time monitoring are necessary to identify deformation progress. Machine vision based on image processing technique was selected to monitor deformation behavior on dieless bellows forming process. The present paper describes real-time monitoring using image processing approach to monitor dimensional profile and temperature distribution during the process. The results show that machine vision is effective and efficient to monitor dynamic deformation of dieless bellows forming proces and able to identify abnormal process condition.

Sign in / Sign up

Export Citation Format

Share Document