Papers by Keyword: Incremental Sheet Forming (ISF)

Abstract: This work presents a novel teaching experience in the framework of final master and bachelor theses within the research line on incremental sheet forming processes. This forming process involves a series of competences dealing with manufacturing technology at a wide multidisciplinary level. This paper analyses these different manufacturing topics and the knowledge acquired by students doing their final theses within this field. This knowledge will be very useful during their future professional career.

Abstract: Incremental Sheet Forming (ISF) process is Innovative and cost effective technology trend for forming products in manufacturing industries. The current research is to study and investigate the influence of incremental sheet forming process parameters on response surfaces of aluminium alloy sheet components. In this experiment, Aluminium alloy AA1050 sheet was selected to process forming by using CNC machining centre without expensive dies. Individual and interactive effect of different factors such as, thickness of sheet, tool diameter, vertical step, feed rate, and tool rotational speed at different levels were assessed to improve the processing time. For the design of experiment (DOE), Taguchi’s L27 orthogonal array was used to investigate and optimize the influencing ISF process parameters. From ANOVA results, it was found that for thickness reduction, the influencing factors were as following; feed rate (21.40 %); for roughness, tool rotation speed (20.43 %) and for hardness, thicknesses of sheet (39.49 %). Response Surface Methodology (RSM) showed that optimal values obtained were 0.46 mm, 10 mm, 0.6818 mm, 2232.32 mm/min., and 2626 rpm for thickness of sheet, tool diameter, vertical step, feed rate and tool rotational speed respectively. For percentage thickness reduction of 59.6%, minimum roughness 2.09μm, and maximum hardness 41.7 BHN, the confirmatory test showed values of 64.78 % thickness reduction, roughness of 2.14μm and hardness of 44.82 BHN that were in agreement with the predicted value.

Abstract: The purpose of the paper is to investigate the dependency of various parameters on metal forming process using mathematical models. The incremental sheet metal forming process was studied using Box–Behnken design of experiments along with response from surface methodology analysis. In the study process factors namely feed rate, speed and coolant were analysed to understand the effect on the surface roughness, percentage (%) of thickness reduction, grain size and hardness of the Aluminium (Al) sheet metal, were examined after forming. The surface model analysis predicts that all four responses of the incremental forms show very strong correlation with the experimental results. The optimized process of incremental forming that runs on maintained levels of predicted factors, yield responses very close to that predicted from the model.

Abstract: ncremental sheet forming (ISF) is a new promising technology due to its flexibility and low-cost tooling properties compared with conventional forming processes. However, it is only suitable for small-batch production because of its incremental feature inducing relative long forming time. Presently, widespread usage of the process is restricted by a lack of predictive understanding of the process due to its complexity. In this paper, the aspect of forming time is studied by investigating the effects of four distinctive process parameters (step over, feed rate, sheet thickness and tool diameter). An effective analysis tool, Taguchi method together with design of experiment (DOE) and analysis of variance (ANVOA) is utilized to study the effects of the four process parameters on forming time and further to optimize parameter combinations in order to minimize forming time. Using these techniques, experimental results show that the step over of spiral tool path is the most important process parameter affecting forming time followed by feed rate. Sheet thickness and tool diameter have little effect on forming time. The comparison between the prediction of optimized parameter combination and the confirmation test result has further demonstrated the effectiveness of the proposed method. It is worth noting that the results of this study will indicate a further direction on how to optimize process parameters to find a balance between forming efficiency (forming time) and forming quality (forming accuracy and surface roughness).

Abstract: Stainless steels are increasingly today applied in industrial use. The metastable structure of austenitic stainless steels enables strain induced martensite formation during plastic deformation. Thus, in order to effectively apply these steels in incremental sheet forming (ISF), it is essential to know their α-martensite transformation tendency in the process. For the four different austenitic stainless steels in the present study, the transformation was found to be very sensitive to the applied process parameters. The martensite formation was more profound with the unstable grades, however, with external heating the martensite formation could be diminished. By optimizing the ISF process, the amount of transformed martensite can be controlled and products with exceptional property combinations can be produced. The novelty of the present paper is to, first, provide information on the influence of strain induced martensite on the incremental forming process and product properties. In addition, based on the observations, propose means to control the transformation. Furthermore, the paper establishes that ISF favours a moderate rate of martensite transformation for extreme formability.

Abstract: Incremental Sheet Forming (ISF) is a new sheet metal forming process characterized by higher formability, product independent tooling and greater process flexibility. A large amount of research work has been spent on ISF process in the last years, but industrial applications are not spreading accordingly. In this paper, numerical simulation, combined with FLD, was performed to analyze the formability of a practical production. Additionally, an actual experiment was done to test and verify the accuracy of numerical simulation analysis results. The high similarity between the analytical prediction values and the measured values indicates it is feasible to predict the formability of the ISF production.

Abstract: Incremental Sheet Forming (ISF) is an emerging process. As a sheet metal forming process, it allows manufacturing components without the development of complex tools in comparison with stamping process. Although existing technical research achievements are plenty, it remains to be improved to make an industrially suitable process. This work is dedicated to the incremental forming of the throttle pedal fixed plate to analyze and figure out the reasonable practical procedure of ISF process, and helpful to promote the industrial applications of ISF.

Abstract: Improvements in parallel computing and adaptive remeshing have permitted to simulate a wide range of metal forming processes within few hours or days on modern multi-core workstations. However, they do not tackle the issues encountered in incremental forming processes, making them very challenging. Multi-mesh methods opens very interesting doors in this domain, making possible to take advantage of adaptive remeshing techniques (optimizing the ratio precision/cost) without its usual drawbacks (loss of information and diffusion issues).We present in this article a fully parallel Dual-Mesh implementation in the commercial FEA software FORGE®, compatible with a wide range of other FEM facilities. Speed-up larger than 4 are common for incremental forming simulations, and speed-up larger than 10 can be reached in favorable cases. Parallel efficiency is the same than for our standard computations (>80% for more than 2000 nodes per core).

Abstract: 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.

Abstract: Single point incremental forming (SPIF) is a modern method of forming sheet metal, where parts can be formed without the use of dedicated dies. The ability of SPIF to form a part is based on various forming parameters. Previous work was not accomplished with the help of design of experiments (DOE), thus reducing the number of parameters varied at any time. This paper presents a Box-Behnken experimental design, which develops the numerical plan, formalizes the forming parameters critical in SPIF and analyse data. The most critical factors affecting SPIF were found to be wall inclination angle, incremental step size, material thickness and tool size. The main effects of these parameters on the quality of the formed parts were studied in detail. Actually this work aims to “optimize the thinning rate and the maximum force by considering the tool diameter and the vertical pitch as unknown parameters for two different wall angles and thicknesses”. To this purpose, an optimization procedure based on the use of response surface methodology (RSM) and genetic algorithms (GA) have been proposed for application to find the optimum solutions. Finally, it demonstrated that the developed methods can solve high non-linear problems successfully. Associated plots are shown to be very efficient for a quick localization of the region of the search space containing the global optimum values of the SPIF parameters.