변형률 속도가 PET섬유의 인장응력-변형률 거동에 미치는 영향

Effect of Strain Rate on the Tensile Stress-Strain Behavior of PET Fibers

By using the non-Newtonian, four elements and elastic-visco-plastic model, equations of the stress-strain curves of PET filaments at different strain rates were derived and discussed with experimental results. Strain rates range from 10$\^$-4/ to 10$\^$-1/ sec$\^$-1/ and experimental results above the yield point deviate from theoretical values about 3∼15％ according to strain rates. The non-Newtonian, four elements and elastic-viscoplastic model is suitable to describe the stress-strain behaviors above the yield point of PET filaments manufactured at various conditions, and initial slope of the stress-strain curves of PET filaments is independent of strain rate.