| Title |
A Plastic Instability Criterion for Sheet Metals |
| Authors |
전기찬(G . Jun); 유동진(D . J . Yoo); 이정우(J . W . Lee) |
| Abstract |
Localized neck was assumed to be initiated by slip on the plane where pure shear condition is attained. From this concept an instability criterion was derived in terms of work harden ing exponent n and the strain ratio R. Hill`s yield criterion proposed in 1948 was employed in the derivation considering only normal anisotropy. The resulting criterion provided entire forming limit diagram in all combinations of major and minor strains with reasonable accuracy for several typical metals. |