Koyanagi Jun, Hasegawa Kodai, Ohtani Akio, Sakai Takenobu, Sakaue Kenichi
Department of Materials Science and Technology, Tokyo University of Science, Japan.
Department of Materials Science and Technology, Graduate School of Tokyo University of Science, Japan.
Heliyon. 2021 Feb 26;7(2):e06335. doi: 10.1016/j.heliyon.2021.e06335. eCollection 2021 Feb.
In this study, a non-linear viscoelastic-viscoplastic constitutive equation for polyamide 6 (PA6) is formulated and a new model is suggested for the viscoplastic part of the equation. The suggested model is empirical but can accurately predict the viscoplastic strain. In this study, creep and recovery tests are conducted to evaluate the viscoplastic strain. Using a non-linear dashpot, a viscoplastic strain is formulated and its parameters are identified for PA6. In addition, a stress relaxation test is conducted, and the relationship between the viscoelastic strain and stress is identified when considering the viscoplastic strain. In this study, the time-temperature superposition principle is thoroughly applied to include the effect of elevated temperature on the viscoelastic-viscoplastic behavior. All material constants in the non-linear viscoelastic-viscoplastic constitutive equation including the time-temperature superposition principle for PA6 are presented in this study.
在本研究中，推导了聚酰胺6（PA6）的非线性粘弹性-粘塑性本构方程，并针对该方程的粘塑性部分提出了一个新模型。所提出的模型是经验性的，但能够准确预测粘塑性应变。在本研究中，进行了蠕变和恢复试验以评估粘塑性应变。使用一个非线性阻尼器，推导了粘塑性应变并确定了其针对PA6的参数。此外，进行了应力松弛试验，并在考虑粘塑性应变的情况下确定了粘弹性应变与应力之间的关系。在本研究中，充分应用了时间-温度叠加原理以纳入高温对粘弹性-粘塑性行为的影响。本研究给出了包括PA6的时间-温度叠加原理在内的非线性粘弹性-粘塑性本构方程中的所有材料常数。
