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RE-PhD Dissertation_signed 2nd page.pdf (2.3 MB)

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DIRECT TESTING OF TIRE TREAD COMPOUNDS AT HIGH FREQUENCIES USING A NEWLY DEVELOPED DYNAMIC MECHANICAL ANALYSIS (DMA) SYSTEM

Esmaeeli, Roja
http://orcid.org/0000-0003-3805-8550
http://rave.ohiolink.edu/etdc/view?acc_num=akron1591741751909052

Abstract Details

2020, Doctor of Philosophy, University of Akron, Mechanical Engineering.
The accurate prediction of tire material properties to improve the tire performance and safety is one of the concerns of tire industry. For improved prediction of the tire wet traction performance, especially for newly developed rubber compounds, the rubber viscoelastic properties should be measured accurately and directly at desired frequency and strain. Therefore, the aim of this study is to design a new High Frequency Dynamic Mechanical Analysis (HFDMA) measurement system that can operate for shear tests at high frequencies with strain amplitudes sufficient for viscoelastic materials operating in high frequency deformation applications, such as tire tread rubbers. The available commercial Dynamic Mechanical Analysis (DMA) systems are not able to run the required viscoelastic material properties measurements directly at the required high frequencies. Thus, the commercial DMA measurement systems use the so called WLF relation, which is based on the time temperature superposition to perform the indirect measurements. During this indirect process, a set of measurements at low frequencies and different temperatures is performed and with the use of the time-temperature superposition principle the results are extrapolated to high frequencies. The aim of this study is to design and test a new HFDMA in order to expand the frequency range of the DMA test and to perform the viscoelastic material properties measurements directly without the use of the time-temperature superposition principle and WLF relation. At the first step, the design process and selecting the proper actuator for the high frequency deformation of the rubber is discussed in this dissertation. Next, the specimen size is chosen with respect to parameters such as shear elastic wave effect, bending, buckling effect and heat generation in the specimen. In order to ensure that the measurements of the HFDMA are repeatable, the repeatability test is discussed in this dissertation. In addition, the Gauge repeatability and reproducibility (Gauge R&R) analysis is done to ensure the results are not affected by different operators and specimens. In addition, with the help of the Gauge R&R analysis, the source of variations in the newly developed measurement system is distinguished. There is not any high frequency forced vibration DMA system available in the research labs and market. Thus, the new HFDMA is validated by comparing its results with a commercial DMA at low frequency for SBR, carbon black filled SBR and Silica filled SBR rubber compound. The results obtain from the commercial DMA at high frequencies are compared with the direct measurements of the HFDMA. Commercial DMAs use the time temperature superposition principle and WLF relation to develop the high frequency results. Thus, this comparison actually shows the difference between direct and indirect testing. The correction factors are presented as a result of this study to use with the commercial DMA and shift the results to the direct high frequency test. Eventually, the viscoelastic constitutive parameters for Generalized Maxwell Model (GMM) for SBR and carbon black filled SBR are obtained from the direct high frequency tests with the use of HFDMA. These parameters can be used in the analytical tools to simulate the material properties.
Siyamak Farhad (Advisor)
Alper Buldum (Committee Member)
Gopal Nadkarni (Committee Member)
Ping Yi (Committee Member)
Truyen Nguyen (Committee Member)
144 p.
Design; Mechanical Engineering; Mechanics; Polymers
Dynamic Mechanical Analysis, DMA, Measurement system , High Frequency, Viscoelastic materials , Tire tread

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Citations

  • Esmaeeli, R. (2020). DIRECT TESTING OF TIRE TREAD COMPOUNDS AT HIGH FREQUENCIES USING A NEWLY DEVELOPED DYNAMIC MECHANICAL ANALYSIS (DMA) SYSTEM [Doctoral dissertation, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1591741751909052

    APA Style (7th edition)

  • Esmaeeli, Roja. DIRECT TESTING OF TIRE TREAD COMPOUNDS AT HIGH FREQUENCIES USING A NEWLY DEVELOPED DYNAMIC MECHANICAL ANALYSIS (DMA) SYSTEM. 2020. University of Akron, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1591741751909052.

    MLA Style (8th edition)

  • Esmaeeli, Roja. "DIRECT TESTING OF TIRE TREAD COMPOUNDS AT HIGH FREQUENCIES USING A NEWLY DEVELOPED DYNAMIC MECHANICAL ANALYSIS (DMA) SYSTEM." Doctoral dissertation, University of Akron, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1591741751909052

    Chicago Manual of Style (17th edition)

akron1591741751909052
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This open access ETD is published by University of Akron and OhioLINK.