Creep Performance Study Of Polyimide Fibers

Polyimide fibers (PI) is an important high-performance fibers with ultra-light,high-strength and high specific modulus, excellent performance ratio, and plays anindispensable role in aerospace, environmental protection, fire protection and otherfields. In this paper, the application background tension cable antenna for polyimidefibers (PI), the use of self-test device was used to test tensile properties and creeprate under different temperature conditions, different loads and differenttemperatures. from molecular motion perspective The fluence of high and lowtemperature, load levels on fiber creep properties was studied, whether throughforeign push creep rate and the steady creep rate of the experimental data to designstudies to determine the useful life of the material to be reliable, stability andsecurity are interested in engineering impact resistance.Through the analysis of creep curves under different temperatures and loads, itis found that creep ratio and creep rate increases with the growth of load ortemperature, moreover, creep curve becomes steeper with the increase of load, inother words, creep time is shorten from the first stage to the second stage. WithAndrade theory, aging theory and four elements theory fitting experimental data, theresults are as followed, the three types of theory can well simulate one-dimensionalcreep constitutive relation of polyimide fiber under constant load, aging theory fitscreep curves better of which the load is5.6N and the temperature is from120℃to270℃, and Andrade theory is more suitable to describe the creep curve of lowtemperature and load; based on previous discussion the conclusion that polyimidefiber has good creep resistance. Through the study of steady-state creep rate offibers under different conditions, it can be obtained that creep activation energy offiber is17.81kJ/mol, and the stress indices of fiber are respectively0.21,0.27and0.45, which correspond to load2.6~3.6N,3.6~4.6N and4.6~5.6N.