Accelerated testing for long-term strength of innovative CFRP laminates for marine use

Toolbox for visco-elastic material modeling of smart lightweight structures

“…Both curves differ from each other only for high temperature because of the reduction in T G due to the moisture uptake. This has also been found in a similar Temperature (DC) Figure 4: Shift functions of the flexural visco-elastic dry, wet, and grand master curves of TS-400, 5 plies study on different types of FRP [6]. Obviously, moisture alters the stiffness of the polymer as seen in Fig.…”

Temperature dependence of glass fiber/epoxy interface normal strength examined by a cruciform specimen method

“…Applying the TTSP to general viscoelastic materials, an elevated temperature condition is equivalent to a slow-speed testing. Both the strength and apparent modulus of matrix decrease with a decrease in testing speed [8][9][10]. Regarding the strength, as shown in Table 3, the matrix strength decreases with temperature that is equivalent to decrease of testing speed, based on the TTSP.…”

“…An accelerated testing method (ATM) is conventionally employed for long-term assurance of composite materials, as represented by Miyano's work [8]. In ATM, the long-term reliability is assumed to be equivalent to the reliability at elevated temperature, based on the time-temperature superposition principle (TTSP).…”

Experimental Study of Static and Fatigue Behavior of CFRP-Balsa Sandwiches under Three-point Flexural Loading

“…The specimens were tested at two levels of accelerated testing (at frequencies of 2.5 Hz and 3 Hz), and the results were extrapolated to the normal test level of 1.5 Hz. In specialty papers (Miyano et al 2006;Miyano et al 2008;Nakada and Miyano 2009;Rajaneesh et al 2016) in the accelerated fatigue tests of the composite structures a frequency value between 1.5 and 2 Hz was used as a normal load regime. Taking into consideration the sandwich structures analysed in this paper and the low performances at mechanical stresses of the balsa wood core, the normal stress level of the load frequency of 1.5 Hz was used.…”

“…Miyano et al (2006) have proposed a method of accelerated testing to predict the life time at fatigue for two kinds of quasi-isotropic CFRP laminates (the first structure was UT500/135 which consists of twill-woven UT500 carbon fiber and the second structure was 135 epoxy resin and T800S/3900-2B which consists of unidirectional T800 carbon fiber and 3900 epoxy resin) subjected to a random combination of frequency, temperature, and stress ratio based on the time-temperature superposition principle. Miyano et al (2008) have presented a new accelerated method to estimate the long-term strength of CFRP laminates for innovative marine under water absorption conditions, at various temperatures and strain rates, for three kinds of CFRP laminates: conventional plain fabric T300 carbon fibers/vinylester, flat yarn plain fabric T700 carbon fibers/vinylester and multi-axial knitted T700 carbon fibers/vinylester. Nakada and Miyano (2009) determined the fatigue life by using accelerated testing methodologies in the marine industry.…”