Applicability condition of time–temperature superposition principle (TTSP) to a multi-phase system

Nakano, Takato

doi:10.1007/s11043-012-9195-8

Cited by 28 publications

(21 citation statements)

References 35 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At a reference temperature of 20 • C the CFRP is far below its glass transition, hence the damping is mostly affected by the elastomer. In addition, Nakano's suggestion [22], that in a multi-phase system only one material may show a temperature dependence for the applicability of the TTS can be considered valid in this temperature range. If one compares the curves of the temperature sweeps of the C-A-C and the A-C-A lay-ups in Figures 5 and 7, an increase in the loss factor can only be seen at a temperature of over 80 • C. Hence, Figure 10a is regarded as valid in the frequency range shown.…”

Section: Influence Of Frequencymentioning

confidence: 99%

“…For these lay-ups the loss factor peak in T g CFRP range is always higher than for the specimens without elastomer (see Figures 5 and 7). However, the dominance of one relaxation mechanism is required for the applicability of the time-temperature superposition by horizontal shifts [21,22]. This might lead to the different locations of the loss factor peaks of the CFRP in the master curves in Figures 9 and 10b as the elastomer might also influence the behavior.…”

Section: Influence Of Frequencymentioning

confidence: 99%

“…However, if the relaxation mechanisms occurring are active at very different temperatures, i.e., if the glass transition temperatures are far apart, then a thermorheologically simple material behavior can be assumed and master curves can be generated by horizontal shifts only [19,21]. Nakano showed analytically that TTS can hold true for a multiphase system when the glass transitions are far apart from each other or do have the same temperature dependency [22]. Hence, for hybrids with glass transitions of the constituents far apart, TTS can hold true and will also be used in this article.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Damping Characterization of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical Dynamic Mechanical Analysis

et al. 2019

View full text Add to dashboard Cite

Lightweight structures which consist to a large extent of carbon fiber reinforced plastics (CFRP), often lack sufficient damping behavior. This also applies to hybrid laminates such as fiber metal laminates made of CFRP and aluminum. Since they are usually prone to vibrations due to their high stiffness and low mass, additional damping material is required to meet noise, vibration and harshness comfort demands in automotive or aviation industry. In the present study, hybrid carbon fiber elastomer metal laminates (HyCEML) are investigated which are intended to influence the damping behavior of the laminates by an elastomer interlayer between the CFRP ply and the aluminum sheets. The damping behavior is based on the principle of constrained layer damping. To characterize the damping behavior, dynamic mechanical analyses (DMA) are performed under tension on the elastomer and the CFRP, and under three point bending on the hybrid laminate. Different laminate lay-ups, with and without elastomer, and two different elastomer types are examined. The temperature and frequency dependent damping behavior is related to the bending stiffness and master curves are generated by using the time temperature superposition to analyze the damping behavior at higher frequencies. A numerical model is built up on the basis of DMA experiments on the constituents and micro mechanical studies. Subsequently, three point bending DMA experiments on hybrids are simulated and the results are compared with the experimental investigations. In addition, a parameter study on different lay-ups is done numerically. Increasing vibration damping is correlated to increasing elastomer content and decreasing elastomer modulus in the laminate. A rule of mixture is used to estimate the laminate loss factor for varying elastomer content.

show abstract

Section: Influence Of Frequencymentioning

confidence: 99%

Section: Influence Of Frequencymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Damping Characterization of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical Dynamic Mechanical Analysis

et al. 2019

View full text Add to dashboard Cite

show abstract

“…TTSP is effective for analyzing the in situ softening of lignin and for improving the understanding of structure/property relationships in plasticized lignocellulose (Salmén 1984;Laborie et al 2004;Chowdhury and Frazier 2013). However, the applicability of TTSP to wood is still controversial, and some researchers stated that it was applicable only under limited conditions (Salmén 1984;Kelley et al 1987;Nakano 1995Nakano , 2013. Salmén (1984) stated that the WLF model was applicable for water-saturated wood when the temperature was within T g to T g + 30°C.…”

Section: Introductionmentioning

confidence: 99%

Frequency-dependent viscoelastic properties of Chinese fir (Cunninghamia lanceolata) under hygrothermal conditions. Part 1: moisture adsorption

Zhan

Jiang

et al. 2019

Holzforschung

View full text Add to dashboard Cite

To elucidate the frequency-dependent viscoelasticity of wood under a moisture non-equilibrium state, changes in stiffness and damping as a function of frequency were investigated during the moisture adsorption process. The moisture adsorption processes were carried out at six temperatures (30–80°C) and three relative humidity levels (30, 60 and 90% RH). During the moisture adsorption process, the wood stiffness decreased, and damping increased with the increment of moisture content (MC). Regardless of the moisture adsorption time, the wood stiffness increased, and damping decreased with the increasing testing frequency. Based on the re-organized Williams-Landel-Ferry (WLF) model, the time-moisture superposition (TMS) relation was assumed to be applicable for developing a master curve of wood stiffness during the moisture adsorption process. The frequency ranges of the stiffness master curves spanned from 16 to 23 orders of magnitude at temperatures ranging from 30 to 80°C. However, the TMS relation was not able to predict the wood damping properties during the moisture adsorption process due to the multi-relaxation system of the wood and the non-proportional relationship between free volume and MC at transient moisture conditions.

show abstract

“…At a higher temperature, shorter time, and lower temperature over a longer period of time, the same mechanical relaxation phenomenon can be observed, which is referred to as the time-temperature superposition principle (TTSP). The TTSP was originally used to analyze material viscoelasticity [25], and it is widely used to analyze the mechanical properties of wood [26], such as wood creep performance [27][28][29]. The TTSP was also used in thermal degradation analysis combined with the Arrhenius equation, and it has been used for the determination of the color change of cellulose [30] and wood-plastic composite discoloration analysis [31].…”

Section: Introductionmentioning

confidence: 99%

Kinetic Analysis of the Color of Larch Sapwood and Heartwood during Heat Treatment

Wei

Zhang

Liu

et al. 2018

Forests

View full text Add to dashboard Cite

Abstract:The kinetics of color changes in larch sapwood and heartwood during heat treatment were investigated in this study in order to determine if the process of color change that occurs in the surface of wood can be regulated. Wood samples were heated at 90, 110, 130, and 150 • C in an oven, vacuum, and in an oven subjected to saturated steam for 3, 6, 9, and 12 h each. The results of the color measurement showed that the values of L* (lightness) and ∆E* (total color difference) decreased and increased in both the sapwood and heartwood, respectively, with increasing temperature and treatment time. The three kinetic model approach, consisting of (i) the time-temperature superposition principle (TTSP); (ii) zero-order reaction model; and, (iii) first-order reaction model, was used to model the kinetics of color changes. The results indicated that the L* value of the sample (including heartwood and sapwood) was well fitted to the first-order reaction model (R 2 = 0.9999). The Arrhenius activation energy was 14.2369 and 11.0984 kJ/mol for the sapwood and heartwood, respectively. The first-order reaction model also showed a better fit for the ∆E* values between sapwood and heartwood with higher R 2 values than the other two methods. Therefore, the color changes of larch wood could successfully be analyzed using the first-order reaction model.

show abstract

Applicability condition of time–temperature superposition principle (TTSP) to a multi-phase system

Cited by 28 publications

References 35 publications

Damping Characterization of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical Dynamic Mechanical Analysis

Damping Characterization of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical Dynamic Mechanical Analysis

Frequency-dependent viscoelastic properties of Chinese fir (Cunninghamia lanceolata) under hygrothermal conditions. Part 1: moisture adsorption

Kinetic Analysis of the Color of Larch Sapwood and Heartwood during Heat Treatment

Contact Info

Product

Resources

About