Time-temperature superposition of flexural creep response of carbon fiber PEKK composites manufactured using different prepreg stacking sequence

2021 ◽  
pp. 089270572110517
Author(s):  
MS Irfan ◽  
RA Alia ◽  
T Khan ◽  
WJ Cantwell ◽  
R Umer
Keyword(s):  
Carbon Fiber ◽  
Master Curve ◽  
Flexural Properties ◽  
Stacking Sequence ◽  
Short Term ◽  
Creep Tests ◽  
Creep Response ◽  
Three Point Bending ◽  
Temperature Superposition ◽  
Time Temperature Superposition

In this work, the long-term creep response of high-performance carbon fiber PEKK (CF/PEKK) composites was evaluated by performing extrapolated short-term flexural creep tests at various temperatures. The time-temperature superposition principle (TTSP) with vertical as well as horizontal shifting was used to generate master curves at reference temperatures of 120°C. Satin weave-based CF/PEKK prepregs were used to manufacture eight-layer composites via compression molding, with three different stacking sequences: (a) zero-direction [0]8 (b) cross-ply [0, 90]4 and (c) quasi-isotropic [90, −45, 45, 0]2 s. The flexural properties under three-point bending arrangement in a universal testing machine were also evaluated. A dynamic mechanical thermal analyzer (DMTA) in three-point bending mode was used to evaluate the temperature-dependent viscoelastic properties of the three types of composites. The creep and creep-recovery behavior was evaluated at 40°C, 80°C, 120°C, 160°C and 200°C. To construct a master curve, extrapolated short-term isothermal creep tests were performed from 120°C to 180°C at the intervals of 10°C. The predicted master curve represents the creep behavior of composites over more than 10 years. It was shown that the quasi-isotropic CF/PEKK composites exhibited 27% and 12% higher creep resistance at 120°C as compared to zero-direction and cross-ply laminates, respectively. Higher flexural modulus (23%) and flexural strengths (33%) were also exhibited by the quasi-isotropic CF/PEKK composites. The final thickness of quasi-isotropic laminates was 8% lower than the 0o laminates. After analyzing the cross-sections of the composites, it was proposed that the superior mechanical properties of the quasi-isotropic laminates could be due to enhanced nesting between neighboring prepreg layers during the compression molding process, which resulted in closer packing of the fibers. It has been shown that the prepreg stacking sequence could affect the creep behavior and flexural properties of the compression-molded CF/PEKK composites.

Prediction of fiber-directional flexural strength of carbon fiber-reinforced polypropylene based on time–temperature superposition principle

2017 ◽  
Vol 52 (6) ◽  
pp. 793-805 ◽  
Author(s):  
Tsuyoshi Matsuo ◽  
Masayuki Nakada ◽  
Kazuro Kageyama
Keyword(s):  
Carbon Fiber ◽  
Flexural Strength ◽  
Master Curve ◽  
Superposition Principle ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Temperature Superposition ◽  
Time Temperature Superposition ◽  
Time Temperature Superposition Principle

This study verified that the time–temperature superposition principle for fiber-directional flexural strength can be applied to thermoplastic composites undergoing instantaneous fast phenomena such as impact failure and long-term phenomena such as creep failure, by constructing the time- and temperature-dependent master curve of relaxation modulus of thermoplastic resin. The master curve could be transformed to another master curve that predicts fiber-directional flexural strength of carbon fiber-reinforced thermoplastic composites based on the micro-buckling failure theory expressed mainly by the resin’s elastic modulus. The experimental results obtained from high-speed bending test, static bending test at various temperatures, and creep bending test demonstrated that kink band failure occurred on the compressive surface of the specimen at every test condition. This validation and verification related to thermoplastic composites made it possible to predict static and dynamic flexural strengths at arbitrary temperature and creep flexural strength.

Temperature Influence on Microindentation Data of a Viscoelastic Material

2013 ◽  
Vol 586 ◽  
pp. 206-209
Author(s):  
Jiří Minster ◽  
Vlastimil Králík ◽  
Jiří Němeček
Keyword(s):  
Mechanical Properties ◽  
Master Curve ◽  
Time Dependent ◽  
Berkovich Indenter ◽  
Temperature Influence ◽  
Short Term ◽  
Temperature Superposition ◽  
Different Temperatures ◽  
Creep Measurements ◽  
Time Temperature Superposition

This paper aims to apply time-temperature superposition to short-term microindentation data measured at different temperatures, and to compare the viscoelastic compliance master curve that is found with data derived earlier from standard macro creep measurements in pressure. Using a sharp standard Berkovich indenter a successful application of this geometry in characterizing time-dependent mechanical properties of viscoelastic materials is confirmed.

Integration of Atomistic Simulation with Experiment Using Time−Temperature Superposition for a Cross-Linked Epoxy Network

2019 ◽  
Author(s):  
Ketan Khare ◽  
Frederick R. Phelan Jr.
Keyword(s):  
Master Curve ◽  
Glassy State ◽  
Superposition Principle ◽  
Quantitative Comparison ◽  
Time Shift ◽  
Data Sets ◽  
Epoxy Network ◽  
Temperature Superposition ◽  
Time Temperature Superposition ◽  
Time Temperature Superposition Principle

<a></a><a>Quantitative comparison of atomistic simulations with experiment for glass-forming materials is made difficult by the vast mismatch between computationally and experimentally accessible timescales. Recently, we presented results for an epoxy network showing that the computation of specific volume vs. temperature as a function of cooling rate in conjunction with the time–temperature superposition principle (TTSP) enables direct quantitative comparison of simulation with experiment. Here, we follow-up and present results for the translational dynamics of the same material over a temperature range from the rubbery to the glassy state. Using TTSP, we obtain results for translational dynamics out to 10<sup>9</sup> s in TTSP reduced time – a macroscopic timescale. Further, we show that the mean squared displacement (MSD) trends of the network atoms can be collapsed onto a master curve at a reference temperature. The computational master curve is compared with the experimental master curve of the creep compliance for the same network using literature data. We find that the temporal features of the two data sets can be quantitatively compared providing an integrated view relating molecular level dynamics to the macroscopic thermophysical measurement. The time-shift factors needed for the superposition also show excellent agreement with experiment further establishing the veracity of the approach</a>.

scholarly journals Mechanical Testing and Modeling of the Time–Temperature Superposition Response in Hybrid Fiber Reinforced Composites

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1178
Author(s):  
Aggelos Koutsomichalis ◽  
Thomas Kalampoukas ◽  
Dionysios E. Mouzakis
Keyword(s):  
Hybrid Composites ◽  
High Stress ◽  
Woven Fabrics ◽  
Mathematical Function ◽  
Ballistic Performance ◽  
Three Point Bending ◽  
Highly Nonlinear ◽  
Nonlinear Stress ◽  
Temperature Superposition ◽  
Time Temperature Superposition

The purpose of this study was to manufacture hybrid composites from fabrics with superior ballistic performance, and to analyze their viscoelastic and mechanical response. Therefore, composites in hybrid lay-up modes were manufactured from Vectran, Kevlar and aluminum fiber-woven fabrics through a vacuum assisted resin transfer molding. The specimens were consequently analyzed using static three-point bending, as well as by dynamic mechanical analysis (DMA). Apart from DMA, time–temperature superposition (TTS) analysis was performed by all available models. It was possible to study the intrinsic viscoelastic behavior of hybrid ballistic laminates, with TTS analysis gained from creep testing. A polynomic mathematical function was proposed to provide a high accuracy for TTS curves, when shifting out of the linearity regimes is required. The usual Williams–Landel–Ferry and Arrhenius models proved not useful in order to describe and model the shift factors of the acquired curves. In terms of static results, the highly nonlinear stress–strain curve of both composites was obvious, whereas the differential mechanism of failure in relation to stress absorption, at each stage of deformation, was studied. SEM fractography revealed that hybrid specimens with Kevlar plies are prone to tensile side failure, whereas the hybrid specimens with Vectran plies exhibited high performance on the tensile side of the specimens in three-point bending, leading to compressive failure owing to the high stress retained at higher strains after the maximum bending strength was reached.

Applicability of time temperature superposition principle to an immiscible blend of polyphenyleneoxide and polyamide

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Narendra A. Hardikar ◽  
Somasekhar Bobba ◽  
Roshan Jha
Keyword(s):  
Storage Modulus ◽  
Master Curve ◽  
Loss Modulus ◽  
Superposition Principle ◽  
Strict Sense ◽  
Cole Plot ◽  
Temperature Superposition ◽  
Immiscible Blend ◽  
Thermorheological Behavior ◽  
Time Temperature Superposition

Abstract The immiscible blend of polyphenyleneoxide (PPO) and polyamide (PA) is used in several applications exposed to high temperature. The complexity of numerical modeling of such materials is dependent on their thermorheological behavior with significant simplification possibilities, if the material is found to follow the time temperature superposition (TTS) principle and show thermorheological simplicity (TRS). Hence as a precursor to selecting accurate constitutive modeling approach, the paper investigates the applicability of the TTS principle and the nature of thermorheological behavior to the blend. Dynamic mechanical analysis (DMA)frequency scans were performed in the range of 0.1–100 rad/s from 0°C to 210°C at 10°C intervals. Temperature dependency was observed on the Cole-Cole plot pointing to the thermorheological complexity and the need for vertical shift factors. 2-D minimization algorithm was used to shift the isotherms horizontally and vertically to obtain master curves. Except, in the vicinity of glass transition temperature T g , the isotherms overlap to form a master curve, but further analysis considering various conditions indicate that in a strict sense TTS is not applicable to the blend when both storage G′ and loss modulus G″ are considered. However, a continuous master curve of storage modulus spanning 31 decades of time is obtained using horizontal shifting alone when loss modulus is neglected. Further testing is required to ascertain if relaxation modulus can be approximated with storage modulus alone before taking recourse to characterization methods developed for thermorheologically complex (TRC) materials.

scholarly journals Experimentation with Flexural Properties of the Carbon Fiber Graphite Fiber and Glass Fiber Composites

2019 ◽  
Vol 8 (4) ◽  
pp. 4272-4277
Keyword(s):  
Silicon Carbide ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Composite Plates ◽  
Bending Test ◽  
Filler Material ◽  
Flexural Properties ◽  
Graphite Fiber ◽  
Three Point Bending

In the present work the flexural properties of selected composite plates are examined. The three point bending test happens to be widely acceptable method for the evaluation of flexural properties of the composite plates because of its simple geometry and structure. In this paper the influence of filler material and thickness of laminates under three point bending load on simply supported pins are reported for selected filler material combination. Filler materials used here are Glass fiber epoxy with silicon carbide, Graphite fiber epoxy with silicon carbide and Carbon fiber epoxy with silicon carbide. Investigation is carried out as per ASTM D790 standard. The mechanical properties such as flexural strength, flexural stiffness of the composite plates were investigated and reported. This work broadly points out that the flexural strength is dependent on the thickness of the laminates and amount of the filler material of the laminated composites. It was found that Carbon fiber composite shows the superior flexural strength with 6 wt% of SiC among the specimens under study.

scholarly journals Time-temperature behavior of carbon/epoxy laminates under creep loading

2020 ◽  
Author(s):  
Heitor L. Ornaghi ◽  
José Humberto S. Almeida ◽  
Francisco M. Monticeli ◽  
Roberta M. Neves ◽  
Maria Odila H. Cioffi
Keyword(s):  
Composite Laminates ◽  
Material Behavior ◽  
Short Term ◽  
Creep Tests ◽  
Advanced Composite ◽  
Wide Range ◽  
Temperature Superposition ◽  
Term Creep ◽  
Creep Loading ◽  
Short Term Creep

Abstract The time-temperature creep behavior of advanced composite laminates is herein determined through a comprehensive set of experiments and analytical modeling. A complete structure versus property relationship is determined through a wide range of temperature and applied stress levels at the three states of the composite: glassy, glass transition, and rubbery regions. Weibull, Eyring, Burger, and Findley models are employed to predict the experimental data and to better elucidate the material behavior. Experimental creep tests are carried out under ten min and two days aiming at calibrating fitting parameters, which are essential to validate short-term creep tests. The Weibull and Eyring models are more suitable for determining the time-temperature superposition (TTS) creep response in comparison to the Burger and Findley models.

Properties and Structure of UV Light Cured CIPP Composites

2021 ◽  
Vol 898 ◽  
pp. 67-72
Author(s):  
Jana Majerová ◽  
Jakub Hodul ◽  
Rostislav Drochytka
Keyword(s):  
Computed Tomography ◽  
Vinyl Ester ◽  
Polyester Resin ◽  
Uv Light ◽  
Bending Test ◽  
Flexural Properties ◽  
Fiber Glass ◽  
Short Term ◽  
Liner Material ◽  
Three Point Bending

One of the methods of curing (Cured-In-Place Pipe) CIPP pipes is the curing using ultraviolet (UV) light. The main difference from common CIPP types is in the structure of the liner material. In terms of material, it is a woven fiber glass fabric which is saturated with vinyl ester or polyester resin. In general, these pipes are more resistant to chemicals and achieve higher values of flexural properties. The paper focuses on the investigation of the short-term mechanical properties using three-point bending test and structure of UV cured CIPP liners. The computed tomography (CT) was used for the analysis of CIPP internal structure and composition.

scholarly journals Integration of Atomistic Simulation with Experiment Using Time−Temperature Superposition for a Cross-Linked Epoxy Network

2019 ◽  
Author(s):  
Ketan Khare ◽  
Frederick R. Phelan Jr.
Keyword(s):  
Master Curve ◽  
Glassy State ◽  
Superposition Principle ◽  
Quantitative Comparison ◽  
Time Shift ◽  
Data Sets ◽  
Epoxy Network ◽  
Temperature Superposition ◽  
Time Temperature Superposition ◽  
Time Temperature Superposition Principle

<a></a><a>Quantitative comparison of atomistic simulations with experiment for glass-forming materials is made difficult by the vast mismatch between computationally and experimentally accessible timescales. Recently, we presented results for an epoxy network showing that the computation of specific volume vs. temperature as a function of cooling rate in conjunction with the time–temperature superposition principle (TTSP) enables direct quantitative comparison of simulation with experiment. Here, we follow-up and present results for the translational dynamics of the same material over a temperature range from the rubbery to the glassy state. Using TTSP, we obtain results for translational dynamics out to 10<sup>9</sup> s in TTSP reduced time – a macroscopic timescale. Further, we show that the mean squared displacement (MSD) trends of the network atoms can be collapsed onto a master curve at a reference temperature. The computational master curve is compared with the experimental master curve of the creep compliance for the same network using literature data. We find that the temporal features of the two data sets can be quantitatively compared providing an integrated view relating molecular level dynamics to the macroscopic thermophysical measurement. The time-shift factors needed for the superposition also show excellent agreement with experiment further establishing the veracity of the approach</a>.

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