Incremental forming deforms a flat sheet metal into a three-dimensional geometry using a Computer-Numerical-Control (CNC) controlled tool without a supporting die. The research objectives of this collaborative international project are to understand the failure mechanism in the incremental forming (IF) experiments; to create a double-side incremental forming technology, such that incremental forming is no longer limited to producing components of geometrical features only on one side of the initial sheet plane; and to discover the potential of generating micro-features on macro-scale curved panels using this new forming process. Our approach is based on the mechanics understanding of failure mechanism in the incremental forming process considering both nonlinear strain paths and local contact pressure. Experimental work will be conducted to verify our failure model. The tool path design will be using a newly proposed inverse strain mapping and minimum damage method. The achievable tolerance and multi-scale feature sizes will be studied here using both experimental and numerical methods.
This project will lay down the solid scientific and technological groundwork for regarding the incremental forming process as a valid means for small-volume productions. This project will also demonstrate a successful model for international collaboration and its effort to enhance the global view of our U.S. students. Co-sponsored by MPM and OISE, this project will support our graduate and undergraduate students to be at Indian institute of Technology, Kanpur (IITK), for several months during the project period. Faculty and students of IITK will visit NU funded by Indo-US forum or other India funding sources. Students will be involved in both research projects and the development of manufacturing class projects. Research results and collaboration model will be disseminated via publications, seminars and workshops.
Incremental forming deforms a flat sheet metal into a three-dimensional geometry using a Computer-Numerical-Control (CNC) controlled tool without a geometric-specific die. The knowledge gained through this research led to one rapid flexible forming method that is cost effective and energy efficient. Potential applications include the fabrication of low-volume or patient-specific products or a prototype at the design phase. Intellectual merits: The research resulted in a better understanding of geometric accuracy, surface finish, forming time and failure mechanism in incremental forming at macro- and micro-scale. Algorithms were generated to reduce forming time while maintaining the desired surface finish; and to achieve forming a straight wall angle using multi-step. An analytical model was developed to calculate the rigid body translations occurred in incremental forming. It was also found that tool rotation can help to increase the formable wall angle in general which is largely attributed to the temperature increase due to friction. Furthermore, a double-side incremental forming technology and its associated forming strategies were proposed to enable forming of a part with double-curvature on both sides of its original plane without the need of resetting the tooling in the middle of the process. Parts were formed to demonstrate the feasibility. A new toolpath strategy called Accumulative DSIF (ADSIF) was formulated. It was found that ADSIF results in significantly enhanced geometric accuracy, increased formability and significantly expanded process capabilities. Broader impact: Research results have been disseminated through nine journal publications, one book chapter, one patent application and many conference papers. Additional industrial collaboration was established to disseminate research results to industry. This project demonstrated a successful model for international collaboration and its effort to enhance the global view of our U.S. students. A large percentage of students (60%) involved in this research were from the underrepresented minority or women. The research work has been used to demonstrate the new process capability to middle school’s science teachers, whom have incorporated the simulation demo into their classroom teaching.
