Experimental validation of the finite element simulation of the first stroke in single point incremental forming (original) (raw)
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Experimentation and FE simulation of single point incremental forming
Materials Today: Proceedings, 2019
One of the emerging flexible forming technologies in the sheet metal engineering is the incremental sheet forming, it uses universal tooling that is mostly part independent. Hence this process provide higher flexibility reducing the product development greatly and making it useful for low volume production. Single Point Incremental forming is drawing attention of the researchers & scientist all over the world because of the attractive characteristics. Like: improved formability, elimination of die & conventional press and ease of operation on general purpose Vertical Machining Centre. As this way of creating sheet metal formed products is in development stage, the factors affecting this needs comprehensive investigations. In this paper experimental and numerical investigation of formability of Aluminium 8011 alloy are presented and compared by preparing a conical frustum shape using SPIF process. The complete process is simulated using CATIA manufacturing simulation model to generate the path of Hemispherical end tool tip. Numeric Control (NC) part program is generated with the help of this simulated path to form the sheet into conical frustum shape on CNC mill machine. Four process parameters viz. vertical step depth, feed rate, spindle speed and angle of cone are chosen for the experimental investigations keeping height of the cone and material sheet thickness constant. Temperature, thickness reduction, strain and machining time are selected as a response variable. Optimizations are performed using TAGUCHI and ANOVA while the numerical study of the process is performed through ANSYS workbench software to predict stress, strain, temperature and thickness Results of experiments and numerical study are in close accord.
Experimental Validation of Finite Element Simulations of Single Point Incremental Forming
2005
Single-point incremental forming (SPIF) is a sheet metal forming technique that has gained particular interest in rapid prototyping and small volume production. The study of the underlying forming mechanisms is supported by new developments in finite element simulations and experimental full field strain measurements. This article aims to describe the possibilities and difficulties encountered during validation of finite element predictions of the incremental forming process. The drawing of a straight line into a metal plate was selected as a first test case for this kind of validation. Results of both finite element simulation and experimental work will be discussed.
INVESTIGATION ON SINGLE POINT INCREMENTAL FORMING PROCESS CONSIDERING VARIOUS TOOL PATH DEFINITIONS
Transstellar Journal , 2019
Single point incremental forming (SPIF) has a great contribution in industrial practice, because the desired parts such as the small-batch production and prototype products can be manufactured just by changing the punch tools and supports. The sheet is formed into desired part using punch tools by producing local plastic deformations at the contact locations based on designed tool paths. This research work is aimed to investigate the formability of SPIF process over the numerical simulations in terms of various geometries and tool paths with varied constant depth, tool radius and feed rate test conditions. The mechanical properties of an aluminum alloy were considered and incorporated into the finite element (FE) code and further, the procedure to perform the forming process was modeled in LS-DYNA tool. To reduce computational time and eliminate the inconsistent results, the symmetry boundary conditions for symmetrical shapes were exploited and discussed. Thereafter, results achieved from the numerical simulations were compared with the desired part to make sure that the suitable FE model was developed. Discussion on the thickness distributions in terms of thinning area, thinning location and its size in percentage are presented. The thickness reduction in both geometries indicates that thinning occurs uniformly in the wall region and small fluctuation noticed near the tool retraction location. In detail, a bending region was observed with continuous thickness reduction and the desired geometry was accomplished from the base plate configuration by controlling the stretching deformation at the start of forming process.
Numerical Studies and Equipment Development for Single Point Incremental Forming
2011
This paper summarizes the achievements obtained so far in the context of a research project carried out at the University of Aveiro, Portugal on both numerical and experimental viewpoints concerning Single Point Incremental Forming (SPIF). On the experimental side, the general guidelines on the development of a new SPIF machine are detailed. The innovation features are related to the choice of a six-degrees-of-freedom, parallel kinematics machine, with a high payload, to broad the range of materials to be tested, and allowing for a higher flexibility on tool-path generation. On the numerical side, preliminary results on simulation of SPIF processes resorting to an innovative solid-shell finite element are presented. The final target is an accurate and fast simulation of SPIF processes by means of numerical methods. Accuracy is obtained through the use of a finite element accounting for three-dimensional stress and strain fields. The developed formulation allows for an unlimited number of integration points through its thickness direction, which promotes accuracy without loss of CPU efficiency. Preliminary results and designs are shown and discussions over the obtained solutions are provided in order to further improve the research framework.
Periodica Polytechnica Mechanical Engineering
Incremental sheet forming (ISF) is an innovative cold forming operation and has enticed great interests owing to its flexibility and capability to manufacture various complex 3D shapes with low costs and minimum requirements. Single point incremental forming (SPIF) is the most popular type of ISF process and has high quality and less occurrence of defects for the formed products if the operating parameters are achieved and evaluated with high precision. In this study, the impact of tool diameter and forming angle on the forming force, thickness distribution, thinning ratio, effective plastic strain, forming depth and fracture behaviour was explored. AA1050 aluminium alloy and DC04 carbon steel were employed to produce a truncated cone in accordance with the SPIF process. A 3D finite element model was required to achieve a well-established investigation. The SPIF of a truncated cone numerical model was adopted to build a model with the same conditions as of the experimental work with...
Strategies and limits in multi-stage single-point incremental forming
The Journal of Strain Analysis for Engineering Design, 2009
Multi-stage single-point incremental forming (SPIF) is a state-of-the-art manufacturing process that allows small-quantity production of complex sheet metal parts with vertical walls. This paper is focused on the application of multi-stage SPIF with the objective of producing cylindrical cups with vertical walls. The strategy consists of forming a conical cup with a taper angle in the first stage, followed by three subsequent stages that progressively move the conical shape towards the desired cylindrical geometry. The investigation includes material characterization, determination of forming-limit curves and fracture forming-limit curves (FFLCs), numerical simulation, and experimentation, namely the evaluation of strain paths and fracture strains in actual multi-stage parts. Assessment of numerical simulation with experimentation shows good agreement between computed and measured strain and strain paths. The results also reveal that the sequence of multi-stage forming has a large e...
Single point incremental forming: state-of-the-art and prospects
International Journal of Material Forming, 2017
Incremental sheet metal forming in general and Single Point Incremental Forming (SPIF) specifically have gone through a period of intensive development with growing attention from research institutes worldwide. The result of these efforts is significant progress in the understanding of the underlying forming mechanisms and opportunities as well as limitations associated with this category of flexible forming processes. Furthermore, creative process design efforts have enhanced the process capabilities and process planning methods. Also, simulation capabilities have evolved substantially. This review paper aims to provide an overview of the body of knowledge with respect to Single Point Incremental Forming. Without claiming to be exhaustive, each section aims for an up-to-date state-of-the-art review with corresponding conclusions on scientific progress and outlook on expected further developments.
Numerical-Experimental Study Regarding the Single Point Incremental Forming Process
MATEC Web of Conferences
The present paper proposes a numerical-experimental comparative study on the single point incremental forming process. A DC04 steel sheet with a thickness of 0.6 mm was used for both the numerical simulation using the finite element method and the experimental research. The type of trajectory used was a spiral trajectory and the finished part obtained was a truncated cone-shaped part. The analysis program used for simulation was Ls-Dyna. The simulations were performed in several variants: with a fixed mesh and with an adaptive mesh, using two different element formulations: 25 (Belytschko-Tsay formulation with thickness stretch) and -16 (fully integrated shell element modified for higher accuracy) and two contact types: automatic surface to surface (ASTS) and forming one way surface to surface (FOSS). The results of the numerical analysis and of the experimental research were focused on determining the major strain, minor strain, thickness reduction and forces at the end of the sing...
Experimental and Finite Element Analysis of Single Stage Single Point Incremental Forming
International Journal of Engineering, 2021
Incremental forming is one of the non-traditional forming processes which is widely used in rapid prototyping and customized component manufacturing. One of the challenges encountered in single stage single point incremental forming (SSSPIF) is difficulty in achieving greater wall angle for a considerable depth. In this research work, the investigation is carried out by experimental and numerical simulation for reaching the maximum wall angle to a possible depth without any defects in SSSPIF. SSSPIF of truncated cone shaped component from 1mm thick AISI304 austenitic stainless steel are made at a different wall angles. Also, numerical simulation using LS-DYNA explicit solver is performed and the results are validated with the experimental values. Components with the wall angle of 64o is successfully made without any defects made in a single stage forming for a depth of 45 mm within the experimented process parameters. Major strain, minor strain and thickness distribution in the sheet material due to forming process are obtianed from experiments and finite element analysis (FEA). From the results of both experiment and FEA, it is observed that the major strain, minor strain and thinning effects are higher in the region below the major diameter of the truncated cone at all experimented wall angles. Also the FEA results have shown good agreement with the experimental values. Further it is seen that the strains are increasing with the increase of wall angle.