Numerical Simulation And Experimention Of Two-Sided Incremental Forming

Sheet metal parts have a wide range of applications in industry. While, the traditional sheet metal forming process requires molds, which leads to a long development cycle and a high manufacturing cost. It is difficult to adapt to the production mode with small quantities and multi varieties. In this regard, the Japanese researcher proposed a novel sheet metal forming technology-sheet metal incremental forming in the late nineties of the20th century. So far, lots of researches on the incremental forming have been done by scholars from various countries. And the single point incremental forming (SPIF) which is relatively mature in use not only shows its forming flexible, but also helps to improve the sheet forming performance. However, it also shows some drawbacks, such as poor forming accuracy.Aiming at the defect of incremental forming, this paper focuses on studying the two-sided incremental forming process (DSIF) processes and proposes two kinds of novel forming toolpaths. The sheet metal forming mechanism is analyzed under these toolpaths using elastic-plastic theory. And the control principle of DSIF is discussed. Meanwhile, the toolpaths are planned based on ANSYS/LS-DYNA finite element software, the simulation model is also built in the type of1060Aluminum. After the numerical simulation is done, the stress and strain distributions during the forming process are analyzed and the difference of forming accuracy and thinning rate in different toolpaths and thicknesses is compared. Furthermore, the forming test is done with the incremental forming machine. The geometric parameters of the parts are measured by CMM and the practical formability and accuracy in DSIF toolpaths are explored.Simulation data show that the alter of sheet thickness does not affect the stress-strain state and thinning rate of the parts significantly, while the1.4mm thick sheet can get a higher forming accuracy. The parts’forming accuracy in DSIF is higher than that in SPIF. And the parts in the supporting toolpath with DSIF can get higher accuracy, more uniform distribution of thinning rate and stress-strain. Experiment results show in the supporting DSIF toolpath, the average and fluctuation range of the offset between experiment data and ideal value in geometric contour are both minimal, which is consistent with the simulation data. The experiment also shows the application of DSIF is feasible.