구성방정식에 의한 폴리에스테르 필름의 응력완화거동 해석 -이온용액중에서의 응력완화거동-

The Interpretation of Stress Relaxation Behaviors of PET Film by Constitutive Equations -Stress Relaxation Behaviors in Ionic Solutions-

To analyze the stress relaxation behaviors of PET film in ionic solutions, 5-element mechanical model and its constitutive equations were proposed. And the constitutive equations having two different relaxation mechanisms were used to examine the validity of constitutive equations in 5-element mechanical model. As the radii of ions were decreased, the relaxation stresses were increased. But the relaxation stresses were increased with the increase of draw ratio, ionic strength and ionic value. Besides the relaxation stress, the parameters of constitutive equations in relaxation process were investigated.