Investigation on the effects of process parameters on the through-thickness shear strain in single point incremental forming using dual level fe modelling and statistical analysis

Khamis Essa, Peter Hartley

School of Mechanical Engineering,,College of Engineering and Physical Sciences,,University of Birmingham,Edgbaston,Birmingham, B15 2TT, UK.

DOI:

https://doi.org/10.7494/cmms.2010.4.0293

Abstract:

Single point incremental forming (SPIF) is a process with the capability to form complex geometries using a tool of very simple geometry, without the need for a matching die. At present, through-thickness modes of deformation and the effects of process parameters on through-thickness shear are not clear. The objectives of this report are firstly, to define the most critical working parameters that influence the through-thickness shear strains and secondly to obtain the optimal combination of these parameters that achieve maximum through-thickness shear deformation. Through-thickness shear strains are considered a direct indication of formability in the SPIF process. A design of experiment (DOE) approach is used to develop the study of various process parameters, in particular step-down size, sheet thickness, tool diameter, friction coefficient and strength coefficient. The example used is the manufacture of a truncated cone by SPIF. A dual-level FE modelling technique is used to simulate the process and obtain the corresponding shear strains for each combination of process parameters. The Analysis of Variance (ANOVA) method is used to analyze the results and obtain the most critical factors. The results show that the shear deformation, and hence the formability, could be increased by increasing the coefficient of friction and sheet thickness and decreasing the step-size down and tool diameter.

Cite as:

Essa, K., & Hartley, P. (2010). Investigation on the effects of process parameters on the through-thickness shear strain in single point incremental forming using dual level fe modelling and statistical analysis. Computer Methods in Materials Science, 10(4), 238 – 278. https://doi.org/10.7494/cmms.2010.4.0293

Article (PDF):

Keywords:

Single point incremental forming, Finite element analysis, Through-thickness deformation modes, Design of experiments, Statistical analysis, Optimization

References:

Allwood, J. M., Shouler, D. R., Tekkaya, A. E., 2007, The Increased Forming Limits of Incremental Sheet Forming Processes, Proceedings of the 12th International Conference on Sheet Metal, Shemet, Palermo, Trans Tech Publication Ltd., 612-628

Ambrogio, G., Cozza, V., Filice, L., Micari, F., 2007, An analytical model for improving precision in single point incremental forming, Journal of Materials Processing Technology, 191(1-3), 92-95.

Ambrogio, G., Filice, L., Fratini, L., Micari, F., 2004, Process Mechanics Analysis in Single Point Incremental Forming. Materials Processing and Design: Modeling, Simulation and Applications – NUMIFORM 2004 -Proceedings of the 8th International Conference on Numerical Methods in Industrial Forming Processes, Eds. S. Ghosh, J.M. Castro, J.K. Lee, Columbus, American Institute of Physics, 922-927.

Bambach, M., Hirt, G., Junk, S., 2003, Modelling and Experimental Evaluation of the Incremental Cnc Sheet Metal Forming Process, Proceedings of the 7th International Conference on Computational Plasticity, eds, Onate, E., Owen, D.R.J., Barcelona, 1-17.

Essa, K., Hartley, P., 2010a, An evaluation of shear deformation mechanisms in single point incremental forming using a dual-level finite-element model, Submitted to CIRP Journal of Manufacturing Science and Technology, May 2010.

Essa, K., Hartley, P., 2010b, Optimization of conventional spinning process parameters by means of numerical simulation and statistical analysis, Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, doi. 10.1243/09544054JEM1786

Filice, L., Ambrogio, G., Micari, F., 2006, On-Line Control of Single Point Incremental Forming Operations through Punch Force Monitoring, CIRP Annals – Manufacturing Technology, 55(1), 245-248.

Fratini, L., Ambrogio, G., Di Lorenzo, R., Filice, L., Micari, F., 2004, Influence of mechanical properties of the sheet material on formability in single point incremental forming, CIRP Annals – Manufacturing Technology, 53(1), 207-210.

Ham, M., Jeswiet, J., 2006, Single Point Incremental Forming and the Forming Criteria for AA3003, CIRP Annals -Manufacturing Technology, 55(1), 241-244.

Ham, M., Jeswiet, J., 2007, Forming Limit Curves in Single Point Incremental Forming, CIRP Annals Manufacturing Technology, 56(1), 277-280.

Hirt, G., Bambach, M., Junk, S., 2003, Modelling of the Incremental CNC Sheet Metal Forming Process, Proceedings of the 10th International Conference on Sheet Metal, University of Ulster.

Hussain, G., Gao, L., Hayat, N., 2009a, Empirical modelling of the influence of operating parameters on the spifability of a titanium sheet using response surface methodology, Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 223(1), 73-81.

Hussain, G., Gao, L., Zhang, Z., 2008, Formability evaluation of a pure titanium sheet in the cold incremental forming process, International Journal of Advanced Manufacturing Technology, 37(9), 920-926.

Hussain, G., Gao, L., Hayat, N., Ziran, Xu., 2009b, A new formability indicator in single point incremental forming, Journal of Materials Processing Technology, 209(9), 4237-4242.

Jackson, K., Allwood, J., 2009, The Mechanics of Incremental Sheet Forming, Journal of Materials Processing Technology, 209 (3), 1158-1174.

Le, V., Ghiotti, A., Lucchetta, G. 2008, Preliminary Studies on Single Point Incremental Forming for Thermoplastic Materials, International Journal of Material Forming, 1, 1179-1182.

Lind, D. A., Marchal, W. G. A., Wathen, S., 2005, Statistical Techniques in Business and Economics, 12th Ed,McGraw Hill Irwin, Boston.

Micari, F., 2004, Single Point Incremental Forming: recent results. Seminar on Incremental Forming. Cambridge University.