Characterizing viscoelastic properties of carbon fiber/epoxy composites using vector fitting method

Abstract

In this work, mechanical properties of a T800 carbon fiber/modified epoxy composite material were researched by using a dynamic mechanical analyzer (DMA) operated under flexural mode. The dynamic mechanical behavior was investigated by DMA at a fixed frequency of 1 Hz. Because mechanical properties of the material were influenced by both time and temperature, its viscoelastic modulus was also considered and accomplished by conducting DMA multiple‐frequency dynamic mechanical experiments. Based on the experimental data, master curves of the storage (E′) and the loss moduli (E″) at a pre‐selected reference temperature were constructed as a function of frequency. The shift factor along the frequency axis was also determined as a function of temperature. Expression of the relaxation modulus in the time domain at the reference temperature was obtained by using vector fitting method. The numerical algorithm result showed excellent correlation to experimental data over the entire range of relaxation. POLYM. COMPOS., 39:E2000–E2005, 2018. © 2017 Society of Plastics Engineers

A method of automatically obtaining master surfaces of resin matrix composites by time–temperature superposition

“…The curves represent the translation results of the curves. Comparing them with the research of Li et al, [17] it can be found that the results of automatic shift and manual shift are consistent.…”

“…Two examples with different DMA test method are used. The first is the transverse unidirectional CFRP with the frequency sweep/temperature step method, which can be found in the research of Li et al [ 17 ] The second is the epoxy resin with the frequency sweep/continuous heating‐up method, which is carried out by us. Under the same heating rate and temperature range, the test time of the continuous heating‐up method is less than that of the temperature step method.…”