Incremental Forming at Multi-Scales

渐进成形是在没有支撑模具的情况下，使用计算机数字控制(CNC)控制的工具将平板金属变形为三维几何形状。这一国际合作项目的研究目标是了解渐进成形(IF)实验中的失效机理；创建一种双面渐进成形技术，使渐进成形不再局限于仅在初始板材平面的一侧产生几何特征的部件；以及发现使用这种新的成形工艺在宏观尺度的曲面上生成微观特征的潜力。我们的方法是基于对渐进成形过程中破坏机理的力学理解，同时考虑了非线性应变路径和局部接触压力。将进行实验工作来验证我们的失效模型。刀具路径设计将使用新提出的逆应变映射和最小损伤方法。本文将使用实验和数值方法研究可实现的公差和多尺度特征大小。该项目将为将渐进成形工艺作为小批量生产的有效手段奠定坚实的科技基础。该项目还将展示国际合作的成功模式及其为增强我们美国学生的全球视野所做的努力。该项目由MPM和OISE共同发起，将支持我们的研究生和本科生在项目期间在坎普尔印度理工学院(IITK)呆上几个月。IITK的教职员工和学生将访问由印美论坛或其他印度资金来源资助的NU。学生将参与研究项目和制造类项目的开发。研究成果和合作模式将通过出版物、研讨会和讲习班进行传播。

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.