Effect of Incremental Depth and Part Shape on Failure Modes in Single Point Incremental Forming of Polymers

2015 ◽  
Author(s):  
Mohammad Ali Davarpanah ◽  
Rajiv Malhotra
Keyword(s):  
Failure Modes ◽  
Incremental Forming ◽  
Single Point ◽  
Rate Of Change ◽  
Single Point Incremental Forming ◽  
Wall Angle ◽  
Cold Forming ◽  
Modes Of Failure ◽  
Polymer Sheets ◽  
Significant Research

Single Point Incremental Forming (SPIF) has received considerable attention recently due to advantages such as part-shape-independent tooling, higher formability and higher process flexibility as compared to conventional forming. While significant research has been performed on SPIF of metals, recent work has also shown the feasibility of using SPIF for cold-forming of thermoplastic polymer sheets. However, the effects of incremental depth and part shape on the modes of failure during polymer SPIF have rarely been investigated. This paper examines the effects of part shape and incremental depth on the formability and failure modes in polymer SPIF. It is shown that greater incremental depths result in greater formability in polymer SPIF. Furthermore, it is shown that increasing the rate of change of the wall angle with the Z depth of the part increases the maximum formability achievable using a given incremental depth. At the same time, it is observed that this dual advantage of greater formability and reduced forming time, possible with higher incremental depths, is limited by the occurrence of sheet wrinkling when the incremental depth becomes too high. Additionally, the dependence of sheet wrinkling on the overall shape of the part being formed is also shown.

A novel multi-step strategy of single point incremental forming for high wall angle shape

2020 ◽  
Vol 56 ◽  
pp. 697-706 ◽  
Author(s):  
Song Wu ◽  
Yunwu Ma ◽  
Leitao Gao ◽  
Yixi Zhao ◽  
Sherif Rashed ◽  
...  
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Wall Angle

Experimental and Simulation Study of Single Point Incremental Forming of Polycarbonate

2019 ◽  
Author(s):  
Saurabh Rai ◽  
Rakesh Kumar ◽  
Harish Kumar Nirala ◽  
Kevin Francis ◽  
Anupam Agrawal
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Material Strength ◽  
Displacement Curve ◽  
Single Point Incremental Forming ◽  
Aircraft Industry ◽  
Forming Process ◽  
Wall Angle ◽  
Safety Glass ◽  
Force Displacement

Abstract Single point incremental forming (SPIF) is more accurate and economical than the conventional forming process for customized products. Majority of the work in SPIF has been carried out on metals. However, polymers are also required to shape. Polycarbonate has wide application in safety glass, bottles, automotive and aircraft industry due to its transparent as well as attractive processing and mechanical properties as compared to other polymeric plastics. In present work, the Polycarbonate (PC) sheet of thickness 1.8 mm is deformed to make a square cup at different angles. Tensile testing is done to analyze the effect of wall angle on the deformed cup. This work illustrates the effect of the SPIF process on material strength in a different directions (vertical and horizontal) of the final deformed product. Tool forces are evaluated using ABAQUS® simulation for SPIF. Numerical simulation approach is used to calculate the fracture energy, which utilizes the force-displacement curve of the specimen and is verified.

Heat Assisted Single Point Incremental Forming of Polymer Sheets

2016 ◽  
Author(s):  
Shubhamkar Kulkarni ◽  
Vijay Sarthy Mysore Sreedhara ◽  
Gregory Mocko
Keyword(s):  
Room Temperature ◽  
Incremental Forming ◽  
Single Point ◽  
Future Research ◽  
Single Point Incremental Forming ◽  
Thermoplastic Polymer ◽  
Localized Deformation ◽  
Hot Air ◽  
Polymer Sheets ◽  
Complex Shapes

The objective of this research is to study the improvement in the formability of thermoplastics using heat assisted single point incremental forming. Single point incremental forming is a production process for forming sheet materials without the use of dedicated tooling (dies/molds). The process is an alternative to thermoforming for low volume forming of sheets. It involves forming the final shape through a series of localized incremental deformations. It has been observed that heat assisted techniques have shown an improvement in the formability limits for sheet metals. In this research, this concept has been tested for improving the formability of polymer sheets. Hot air us used to increase the temperature within a localized region in front of the tool. A single point incremental forming device is modified through the development of a specialized tool holder and nozzle which heats the polymer sheet to temperatures higher than the room temperature but below the glass transition temperature of the polymer and applies the forming loads. The results from the experiments are summarized as: i) the formability angle increases of polystyrene from 27 degrees to 46 degrees when comparing room temperature forming to forming at an elevated temperature (170°F–180 °F), ii) a reduction in the forces needed for forming is observed qualitatively, and iii) the surface finish on the formed parts do not show visible change. This demonstrates promise of manufacturing complex shapes from thermoplastic polymer sheets using heat assisted incremental forming. Future research includes 1) simulating the localized deformation of the material to enable process planning, 2) quantifying the forming forces and heat control of the system, and 3) exploring the manufacturing technique to other materials.

Improvement of Formability in Single Point Incremental Forming of DP 1000 Steel by Induction Heating

2015 ◽  
Vol 794 ◽  
pp. 67-74
Author(s):  
Amar Al-Obaidi ◽  
Verena Kräusel ◽  
Dirk Landgrebe
Keyword(s):  
Induction Heating ◽  
Steel Sheet ◽  
Incremental Forming ◽  
Heating Temperature ◽  
Single Point ◽  
Operational Efficiency ◽  
Single Point Incremental Forming ◽  
Lower Side ◽  
Wall Angle ◽  
Optimum Heating

This paper provides results from experiments to improve formability of DP 1000 steel in forming a complex profiles in single point incremental forming with induction heating. High attention is rewarded to the straight effect of induction power and tool settings, in order to determine if the heating temperature is sufficient for raising the formability. The steel sheet is formed by a punch in the upper side and synchronized by induction heating for the sheet on the lower side. Investigations show a maximum achievable wall angle of 70°, which was accomplished at 20 kW induction power for the two formed shapes pyramid and cone. The operational efficiency improved by reducing both the forming time and the induction power required obtaining an optimum heating temperature for the sheet blank. The presented method can be used to increase the formability of difficult-to-form metals by using a simple setup.

Manufacture of Accurate Titanium Cranio-Facial Implants with High Forming Angle Using Single Point Incremental Forming

2013 ◽  
Vol 549 ◽  
pp. 223-230 ◽  
Author(s):  
Joost R. Duflou ◽  
Amar Kumar Behera ◽  
Hans Vanhove ◽  
Liciane S. Bertol
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Design Feature ◽  
Feature Analysis ◽  
Medical Applications ◽  
Single Point Incremental Forming ◽  
Wall Angle ◽  
Titanium Grade ◽  
Intermediate Part ◽  
Forming Angle

One of the key application areas of Single Point Incremental Forming is in the manufacture of parts for bio-medical applications. This paper discusses the challenges associated with the manufacture of cranio-facial implants with extreme forming angles using medical grade titanium sheets. While on one hand, the failure wall angle is an issue of concern, the parts also need to be manufactured with accuracy at the edges where the implants fit into the human body. Systematic steps taken to overcome these challenges, using intelligent intermediate part design, feature analysis and compensation, are discussed. A number of case studies illustrating the manufacture of accurate parts in aluminium, stainless steel and titanium grade-2 alloy are discussed.

STUDY ON FORMING FORCES OF PARTS PROCESSED BY SINGLE POINT INCREMENTAL FORMING WITH DUMMY SHEET

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Vikas Sisodia ◽  
Shailendra Kumar
Keyword(s):  
Process Parameters ◽  
Feed Rate ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Thickness ◽  
Single Point Incremental Forming ◽  
Forming Force ◽  
Step Size ◽  
Wall Angle ◽  
Influence Of Process Parameters

The present paper describes the experimental investigation on influence of process parameters on maximum forming force in Single Point Incremental Forming (SPIF) process using dummy sheet. Process parameters namely dummy sheet thickness, tool size, step size, wall angle and feed rate are selected. Taguchi L18 orthogonal array is used to design the experiments. From the analysis of variance (ANOVA) dummy sheet thickness, tool size, step size and wall angle are significant process parameters while feed rate is insignificant. It is found that as dummy sheet thickness, tool size, step size and wall angle increase magnitude of peak forming force increases while there is marginal decrease in forming force as feed rate increases. Predictive model is also developed for forming force. Validation tests are performed in order to check the accuracy of developed model. Optimum set of process parameters is also determined to minimize forming force. Experimental results are in good agreement with results predicted by the developed mathematical model.

On the Effect of Curvature Radius on the Spif-Ability

2010 ◽  
Vol 129-131 ◽  
pp. 1222-1227 ◽  
Author(s):  
Ghulam Hussain ◽  
Gao Lin ◽  
Nasir Hayat ◽  
Asif Iqbal
Keyword(s):  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Single Point ◽  
Curvature Radius ◽  
Single Point Incremental Forming ◽  
Test Results ◽  
Forming Process ◽  
Wall Angle ◽  
Metal Forming Process

Single Point Incremental Forming (SPIF) is a novel sheet metal forming process. The formability (i.e. spif-ability) in this process is determined through Varying Wall Angle Conical Frustum (VWACF) test. In this paper, the effect of variation in the curvature radius, a geometrical parameter of test, on the test results is investigated. A series of VWACF tests with a variety of curvature radii is performed to quantify the said effect. It is found that the spif-ability increases with increasing of curvature radius. However, any variation in the curvature radius does not affect the spif-ability when the normalized curvature radius (i.e. curvature radius/tool radius) becomes higher than 9.

Force Modeling in Single Point Incremental Forming of Variable Wall Angle Components

2011 ◽  
Vol 473 ◽  
pp. 833-840 ◽  
Author(s):  
Rogelio Pérez-Santiago ◽  
Isabel Bagudanch ◽  
Maria Luisa García-Romeu
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Fem Simulation ◽  
Single Point Incremental Forming ◽  
Forming Force ◽  
Wall Angle ◽  
Important Indicator ◽  
Force Modeling ◽  
Variable Wall ◽  
Computational Intelligence Methods

Prediction of forming forces in Incremental Sheet Forming (ISF) is specially important in the case of using adapted machinery not designed for the process. Moreover, forming force is an important indicator that can be monitored on-line and utilized for real time process control. Besides experimentation, simulations based on the Finite Element Method (FEM) have been utilized as a reliable source of process force data. Nevertheless, the long solution times required to simulate ISF renders difficult its inclusion into a process optimization chain. In consequence, models that predict the forces required to manufacture simple parts have appeared. This work begins with a review of forming force models available for Single Point Incremental Forming (SPIF). Then, an equation recently proposed in the literature is compared with published experimental results of SPIF under different working conditions. The same data is employed to verify our own FEM simulations. Finally, the above-mentioned formula and FEM simulation were applied to predict the forming force of Variable Wall Angle (VWA) geometries where available force information is limited. Besides the applicability assessment of the equation, results will supplement a future experimental campaign focused in modeling geometries of intermediate complexity level by means of Computational Intelligence methods.

Sign in / Sign up

Export Citation Format

Share Document