Investigation and optimization of deformation energy and geometric accuracy in the incremental sheet forming process using response surface methodology

Abstract

Incremental sheet forming (ISF) is a promising manufacturing process that features benefits of reduced forming forces, enhanced formability and greater process flexibility. It also has a great potential to achieve economic payoff for rapid prototyping applications and for small quantity production in various applications. However, limited research has been conducted from the sustainability point of view, particularly for energy consumption. More consumed energy will generate more heat and affect tool and product wear. Also, geometric accuracy is still one of the dominant limits for the further development and commercialization of the ISF technology. Therefore, the aim of this study is to investigate how different process parameters affect the consumed energy during the forming process and also find the optimal working condition for lower deformation energy with higher geometric accuracy. A Box-Behnken design of 27 tests for pyramidforming processes have been performed for a multi-objective optimisation that considers four factors: step down, sheet thickness, tool diameter and wall angle at three levels. The deformation energy during the forming process was calculated based on the measured forming forces. It was found that the deformation energy heavily depends on the sheet thickness because of higher plastic energy required to deform the material. Increasing step-down size within a limited range or decreasing the wall angle is also an effective approach to reduce the deformation energy. Moreover, the effects of various process parameters on the global geometric accuracy have also been investigated. The geometric error has been empirically predicted by quadratic equations giving the influence of the most influential forming parameters. It was concluded that the geometric quality is largely determined by the quadratic effect of wall angle, the linear effect of sheet thickness and the interaction effect of thickness and step down. Finally, the optimal working conditions for both independent and simultaneous minimisation of deformation energy and geometric error during the pyramid-forming process are provided.

Modeling and Analysis of Single Point Incremental Forming Force with Static Pressure Support and Ultrasonic Vibration

“…After preheating, the accuracy of the part was clearly improved, and the wall thickness distribution was more uniform. Yanle Li et al [7] measured the accuracy of the part by the axial error. According to the results, the optimum combination of the process parameters was obtained, which reduced the deformation energy and improved the forming accuracy at the same time.…”

Single point incremental forming: An assessment of the progress and technology trends from 2005 to 2015

“…Li et al [149] analyzed the impact of several process parameters on deformation energy and shape accuracy. They used response surface methodology coupled with multi-objective optimization techniques to analyze the influence of 5 factors: step down, sheet thickness, tool diameter and wall angle at three levels using a Box-Behnken design of experiments.…”

Research on the Radial Accuracy of Ultrasonic Vibration-Assisted Single Point Incremental Forming Parts

“…In order to improve the poor geometric accuracy, other attempts have been presented. It includes experimental investigation of process parameters [11], hybrid ISF processes [12][13][14], the use of partially cut-out blanks [15], and a multistage strategy [16].…”