The cause-effect statistical analysis of the post-forming strength of a thermoplastic sheet

Abstract

Thermoplastics are extensively used materials for the lightweight construction. The forming of thermoplastics is relatively a new area in the Incremental Sheet Forming (ISF) process. Upon deformation, the material is likely to experience a change in the strength. The deformation in ISF is affected by the process parameters. Therefore, the present study is focused on identifying the parameters that are influential on the post-forming strength of a Polypropylene sheet. This objective is fulfilled through performing a statistical cause-effect analysis. A Design of Experiment (DoE) comprising of the factorial design is conducted. The analysis of variance is performed on the strength results. It is found that the forming angle, tool diameter and rotational speed are the main influential parameters with the forming angle as the most significant one. Further, these effects are interactive in nature. The interactions plots are presented in this work that can act as process maps. Moreover, the prediction models are proposed that can help in estimating the post-forming strength of the experimental material and thus can be utilized for the optimization purpose. Keywords: Incremental sheet forming, Thermoplastic, Strength, Parameters, Empirical model