Surface Waviness and Wrinkling in Sheet Metal Forming

本研究计划的目的是深入了解在钣金成形过程中可能发生的相对未开发的表面波纹（或起皱）区域，以基本了解材料参数对导致表面波纹的工艺参数的影响。并为在高强度材料成型过程中避免此类缺陷提供技术指导。研究内容包括：(1)外围夹紧钣金的矩形和方形冲头拉伸实验研究；(2)矩形和方形冲头拉伸分析；(3)研究各种本构方程，并建立最适合预测钣金表面波纹/起皱的本构方程；(4)选定材料的双轴强度实验测定；(5)建立无表面波纹板成形的工艺设计准则，并在实际冲压工艺中对这些准则进行测试。表面波纹是钣金成形过程中的主要失效类型之一，这是许多工业中使用的制造过程。所提出的研究将导致更好地理解这一失效问题，并导致在钣金成形工艺的改进。这项研究将由两所大学联合进行，并由一个国家实验室和一个工业公司合作。

The objective of this research proposal is to gain an insight into the relatively unexplored area of surface waviness (or wrinkling) which can occur during sheet metal forming, to obtain a fundamental understanding of the influence of material parameters on those process parameters that cause surface waviness, and to provide technical guidelines for avoiding such defects in forming high-strength materials. The research will include: (1) Experimental studies on rectangular and square punch stretching of peripherally clamped sheet metals, (2) Analysis of rectangular and square punch stretching, (3) Study of various constitutive equations and establishment of those best suited for predicting surface waviness/wrinkling in sheet metal, (4) Experimental determination of biaxial strength of selected materials, and (5) Establishment of process design guidelines for forming panels without surface waviness and testing those guidelines on an actual stamping process. Surface waviness is one of the main types of failures in the sheet metal forming process which is a manufacturing process employed in many industries. The proposed research should lead to a better understanding of this failure problem and result in an improvement in the sheet metal forming process. This research will be conducted jointly by two universities with collaboration from a national laboratory and an industrial company.