The new concept of forming limit curve
Abstract
A very important tool in the description of sheet metal formability is the well known forming limit curve (FLC), the prediction of which is generally based on models using instability theories. Our experimental observations indicate that the surface roughness of as-received metal sheets generally does not lead to strain localization. At the same level of effective strain, the internal damage of a metal sheet is the most severe situation in the plane strain state. When deformation is in a state of tension, damage development results in the drifting of the strain state to plane strain state. When deformation is in a state of tension compression, the stretch caused by load instability also leads to the development of plane strain. Based on these results, a united model for the construction of both the left and right half of the FLC is proposed. FLCs predicted by the new model match experimental results well, and the new model is proven to be better than the M-K theory.
- Publication:
-
Beijing University Aeronautics and Astronautics Journal
- Pub Date:
- October 1992
- Bibcode:
- 1992BUAAJ...4...48C
- Keywords:
-
- Forming Techniques;
- Metal Sheets;
- Load Distribution (Forces);
- Strain Distribution;
- Structural Stability;
- Surface Roughness;
- Mechanical Engineering