WANG JINGHUI, LI JIKANG, LIU ZHENG, et al. CREEP BEHAVIOR AND CONSTITUTIVE DESCRIPTION OF POLYTETRAFLUOROETHYLENE UNDER TEMPERATURE-STRESS COUPLING. [J]. Journal of mechanical strength , 2024, 46(4): 959-968.
DOI:
WANG JINGHUI, LI JIKANG, LIU ZHENG, et al. CREEP BEHAVIOR AND CONSTITUTIVE DESCRIPTION OF POLYTETRAFLUOROETHYLENE UNDER TEMPERATURE-STRESS COUPLING. [J]. Journal of mechanical strength , 2024, 46(4): 959-968. DOI: 10.16579/j.issn.1001.9669.2024.04.027.
CREEP BEHAVIOR AND CONSTITUTIVE DESCRIPTION OF POLYTETRAFLUOROETHYLENE UNDER TEMPERATURE-STRESS COUPLING
Polytetrafluoroethylene(PTFE)has the advantages of high and low temperature resistance
chemical corrosion resistance and high thermal stability
and has become an indispensable sealing material in the industrial field.Its compression performance is crucial to the safe service of the sealing structure.By carrying out the compression experiments and compression creep experiments on PTFE
the compression properties of PTFE at different temperatures were studied
and the coupling effect of stress and temperature on creep behavior was explored.The results show that the compressive yield strength and compressive modulus of PTFE decrease with the increase of temperature.The compression creep performance is influenced by the coupling of temperature and stress.At the same temperature
the instantaneous strain and creep rate of PTFE increase with the increase of stress.Under the same stress
as the temperature increases
the compressive modulus decreases
the molecular energy and free volume increase
resulting in an increase in the instantaneous strain and creep of PTFE
and an increase in the total strain.Finally
the Burgers model
Findley model
and Time-Hardening model were used to analyze the creep behavior of PTFE under different loading conditions.It was found that the Burgers model and Findley model can better describe the creep behavior of PTFE at different temperatures.This study can provide theoretical guidance and data support for the design and engineering application of sealing structures that consider the compressive creep performance of PTFE.
关键词
聚四氟乙烯压缩蠕变试验温度-应力耦合本构模型
Keywords
PolytetrafluoroethyleneCompression creep testTemperature-stress couplingConstitutive model