effective strain
2.It is shown that for the same effective strain range, when the length of crackle is smaller than 0.2 mm,the thermal fatigue life is lower than that of elevated temperature LCF in effective temperature, when the length of fatigue crackle is equal to 0.2 mm, the multiaxial thermal fatigue life of various upper limit temperature is just the same as that of elevated temperature LCF in effective temperature.
5.The cage roll forming process of ERW pipes is quite complicated, which involves geometry nonlinearity, material nonlinearity and boundary nonlinearity. In order to understand the deformation behavior of sheet metals better and avoid product defect, a large deformation elastic-plastic finite element model of ?273mm weld pipe cage forming mill, based on the Updated Lagrangian method, is established and simulated through adopting dynamic explicit algorithm. Roll flower, transverse effective plastic strain, and longitudinal strain of the deformed strip at different forming sections are obtained.
