论文信息 - Aspects of automated measurement of proportional and non-proportional deformation in sheet metal forming

Aspects of automated measurement of proportional and non-proportional deformation in sheet metal forming

Abstract This paper evaluates techniques of surface strain analysis in sheet metal forming based on a two-dimensional grid. Deficiencies of circle grid analysis, which in general cannot be used to measure non-proportional deformation, are discussed. An improved technique utilising a grid of squares or quadrilaterals for the automatic measurement of strains and stresses is presented. The advantage of applying a stress limit curve (SLC), instead of the forming limit curve (FLC), in the experimental analysis of deformation and in the evaluation of forming severity is discussed.

M. Sklad

[1] Z. Marciniak,et al. Limit strains in the processes of stretch-forming sheet metal , 1967 .

[2] R. Sowerby,et al. A theoretical and experimental investigation of limit strains in sheet metal forming , 1996 .

[3] Thomas B. Stoughton,et al. A general forming limit criterion for sheet metal forming , 2000 .

[4] H. W. Swift. Plastic instability under plane stress , 1952 .

[5] R Sowerby,et al. The determination of the equivalent strain in finite, homogeneous deformation processes , 1983 .

[6] R. Hill. A theory of the yielding and plastic flow of anisotropic metals , 1948, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.