熱可塑性プラスチックの負荷・除荷変形挙動とその温度依存性

抄録

Development of an engineering method for predicting strain ratcheting in an engineering thermoplastic polyamide 6 (PA6) has been attempted. For this purpose, the ratcheting behavior of PA6 is studied with emphasis on its temperature dependence. First, uniaxial ratcheting tests with different levels of maximum stress are performed on coupon specimens at different temperatures, respectively. The experimental results show that the accumulation of ratcheting strain in PA6 is significantly dependent on temperature as well as the maximum level of stress. The ratcheting behavior is similar to the transient creep behavior under constant stress in all aspects of its stress and time dependence. It is demonstrated that a master curve can be identified for the uniaxial ratcheting data for PA6 over a range of temperature by scaling the time axis with the help of a shift factor that depends on stress.