Analysis and optimization of the surface waviness in the single-point incremental sheet metal forming
Presence of waviness in the incremental sheet forming has a detrimental effect on the surface quality of parts, especially on the appearance of those covered with paint. In this paper, the effects of tool diameter, feed rate, spindle speed, and vertical step have been studied on the surface waviness using an innovative method. The proposed method is based on the root mean square deviation of the height of the points located on the wavy surface. In this way, some points are selected on the formed wall and their coordinates are measured using a coordinate measuring machine. Taguchi design of experiments and the analysis of variance are used for studying and optimizing the effects of the four process parameters and their combinations to minimize the waviness of the formed wall. The results show that by reducing the vertical step and increasing the tool diameter, the waviness is decreased. It is also found that the feed rate and the spindle speed have little effect on the waviness. Additionally, from a confirmation test, the results illustrate that the Taguchi method and the analysis of variance provide an efficient and effective method for determination of the optimum level of each process parameter to have the minimum surface waviness.