Multi-Stage Two Point Incremental Sheet Forming

In incremental sheet forming, the thickness of parts decreases with the sine law as the forming slope increases, resulting in serious thinning or even fracture of parts. For industrial products, extreme thinning of parts can not meet the design requirements, seriously affecting the application of incremental sheet forming in the industrial field. Multi-stage incremental sheet forming is found to effectively improve the thickness distribution of parts. For multi-stage two point incremental sheet forming, there are a great variety of multi-stage strategies, such as parallel linear tool-path strategy, parallel arcs tool-path strategy, variable angle straight lines tool-path strategy, and stretch-bend assist multi-stage strategy. However, which multi-stage strategy is the best multi-stage strategy is not conclusive. Therefore, in this paper, a square cone is selected to analyse the influence of tool-path strategy on thickness distribution. Then, the best multi-stage strategy is obtained by comparing the thickness distribution with different strategies. Finally, by analysing the change of strain condition with an increase in stage, the causes of different strategies for increasing the thickness distribution are obtained.