TY - JOUR
T1 - Extracting elastic modulus at different strain rates and temperatures from dynamic mechanical analysis data
T2 - A study on nanocomposites
AU - Xu, Xianbo
AU - Koomson, Chrys
AU - Doddamani, Mrityunjay
AU - Behera, Rakesh Kumar
AU - Gupta, Nikhil
N1 - Funding Information:
This work is supported the Office of Naval Research N00014-10-1-0988 . Partial support from NYUAD Dean of Engineering for MD is acknowledged. The authors thank the MAE Department at NIT-K and MAE Department at NYU for providing facilities and support. Steven E. Zeltmann is thanked for useful discussions.
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Viscoelastic nature of polymers makes their properties strongly dependent on temperature and strain rate. Characterization of material properties over a wide range of strain rates and temperatures requires an expensive and time consuming experimental campaign. While viscoelastic properties of materials are widely tested using dynamic mechanical analysis (DMA) method, the frequency dependent component of the measured properties is underutilized due to a lack of correlation between frequency, temperature, and strain rate. The present work develops a method that can extract elastic modulus over a range of strain rates and temperatures from the DMA data for nanocomposites. Carbon nanofiber (CNF) reinforced high-density polyethylene (HDPE) matrix nanocomposites are taken as the study material. Four different compositions of CNF/HDPE nanocomposites are tested using DMA from 40 to 120 °C at 1–100 Hz frequency. First, time-temperature superposition (TTS) principle is used to develop an extrapolation for the results beyond the test parameter range. Then the TTS curve is transformed to a time domain relaxation function using integral relations of viscoelasticity. Finally, the strain rate sensitive elastic modulus is extracted and extrapolated to room temperature. The transform results are validated with tensile test results and the error found to be below 13.4% in the strain rate range 10−5 to 10−3 for all four nanocomposites. Since the materials are tested with the aim of finding a correlation among the test methods, the quality of the material is not a study parameter and the transform should yield accurate results for any material regardless of composition and quality.
AB - Viscoelastic nature of polymers makes their properties strongly dependent on temperature and strain rate. Characterization of material properties over a wide range of strain rates and temperatures requires an expensive and time consuming experimental campaign. While viscoelastic properties of materials are widely tested using dynamic mechanical analysis (DMA) method, the frequency dependent component of the measured properties is underutilized due to a lack of correlation between frequency, temperature, and strain rate. The present work develops a method that can extract elastic modulus over a range of strain rates and temperatures from the DMA data for nanocomposites. Carbon nanofiber (CNF) reinforced high-density polyethylene (HDPE) matrix nanocomposites are taken as the study material. Four different compositions of CNF/HDPE nanocomposites are tested using DMA from 40 to 120 °C at 1–100 Hz frequency. First, time-temperature superposition (TTS) principle is used to develop an extrapolation for the results beyond the test parameter range. Then the TTS curve is transformed to a time domain relaxation function using integral relations of viscoelasticity. Finally, the strain rate sensitive elastic modulus is extracted and extrapolated to room temperature. The transform results are validated with tensile test results and the error found to be below 13.4% in the strain rate range 10−5 to 10−3 for all four nanocomposites. Since the materials are tested with the aim of finding a correlation among the test methods, the quality of the material is not a study parameter and the transform should yield accurate results for any material regardless of composition and quality.
KW - Dynamic mechanical analysis
KW - Elastic modulus
KW - High strain rate
KW - Viscoelasticity
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U2 - 10.1016/j.compositesb.2018.10.015
DO - 10.1016/j.compositesb.2018.10.015
M3 - Article
AN - SCOPUS:85054426600
VL - 159
SP - 346
EP - 354
JO - Composites Part B: Engineering
JF - Composites Part B: Engineering
SN - 1359-8368
ER -