The strain yield locus of the stress yield criterion was advanced and the strainellipse method for calculating the limit bulging coefficient was given.
提出应力屈服条件的应变屈服轨迹，给出了复合胀形极限成形系数的解法；
2
Thecircular cross section turns into ellipse as the ratcheting strain accumulates.
随着棘轮应变的产生，直管圆截面变为椭圆截面。
3
The strain was gram negative, ellipse cell, no spores and no flagellum.