### Abstract

A method to obtain the Young's relaxation modulus and time-dependent Poisson's ratio simultaneously by using DMA is developed with the assumption of constant bulk modulus instead of constant Poisson's ratio. The constant bulk modulus is then calculated by either instantaneous response or the equilibrium response of the time-dependent Poisson's ratio. The modulating Young's moduli and characteristic times that measured by DMA are corrected analytically by using the developed formulas. The time-dependent Poisson's ratio is then obtained from the corrected modulating Young's moduli and the constant bulk modulus. As an application example, the method is applied to the DMA measurement of an epoxy molding compound (EMC). Although the correction to Young's relaxation modulus is very small, the viscoelastic Poisson's ratio varies significantly over time from 0.4 to 0.496, and can't be assumed as a constant.

Original language | English |
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Pages (from-to) | 153-159 |

Number of pages | 7 |

Journal | Procedia Engineering |

Volume | 79 |

DOIs | |

Publication status | Published - 2014 Jan 1 |

Event | 37th National Conference on Theoretical and Applied Mechanics, NCTAM 2013, Conjoined with the 1st International Conference on Mechanics, ICM 2013 - Hsinchu, Taiwan Duration: 2013 Nov 8 → 2013 Nov 9 |

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### All Science Journal Classification (ASJC) codes

- Engineering(all)

### Cite this

*Procedia Engineering*,

*79*, 153-159. https://doi.org/10.1016/j.proeng.2014.06.324

}

*Procedia Engineering*, vol. 79, pp. 153-159. https://doi.org/10.1016/j.proeng.2014.06.324

**Using DMA to simultaneously acquire young's relaxation modulus and time-dependent Poisson's ratio of a viscoelastic material.** / Chen, Dao Long; Chiu, Tz Cheng; Chen, Tei Chen; Chung, Ming Hua; Yang, Ping Feng; Lai, Yi Shao.

Research output: Contribution to journal › Conference article

TY - JOUR

T1 - Using DMA to simultaneously acquire young's relaxation modulus and time-dependent Poisson's ratio of a viscoelastic material

AU - Chen, Dao Long

AU - Chiu, Tz Cheng

AU - Chen, Tei Chen

AU - Chung, Ming Hua

AU - Yang, Ping Feng

AU - Lai, Yi Shao

PY - 2014/1/1

Y1 - 2014/1/1

N2 - A method to obtain the Young's relaxation modulus and time-dependent Poisson's ratio simultaneously by using DMA is developed with the assumption of constant bulk modulus instead of constant Poisson's ratio. The constant bulk modulus is then calculated by either instantaneous response or the equilibrium response of the time-dependent Poisson's ratio. The modulating Young's moduli and characteristic times that measured by DMA are corrected analytically by using the developed formulas. The time-dependent Poisson's ratio is then obtained from the corrected modulating Young's moduli and the constant bulk modulus. As an application example, the method is applied to the DMA measurement of an epoxy molding compound (EMC). Although the correction to Young's relaxation modulus is very small, the viscoelastic Poisson's ratio varies significantly over time from 0.4 to 0.496, and can't be assumed as a constant.

AB - A method to obtain the Young's relaxation modulus and time-dependent Poisson's ratio simultaneously by using DMA is developed with the assumption of constant bulk modulus instead of constant Poisson's ratio. The constant bulk modulus is then calculated by either instantaneous response or the equilibrium response of the time-dependent Poisson's ratio. The modulating Young's moduli and characteristic times that measured by DMA are corrected analytically by using the developed formulas. The time-dependent Poisson's ratio is then obtained from the corrected modulating Young's moduli and the constant bulk modulus. As an application example, the method is applied to the DMA measurement of an epoxy molding compound (EMC). Although the correction to Young's relaxation modulus is very small, the viscoelastic Poisson's ratio varies significantly over time from 0.4 to 0.496, and can't be assumed as a constant.

UR - http://www.scopus.com/inward/record.url?scp=84949134228&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84949134228&partnerID=8YFLogxK

U2 - 10.1016/j.proeng.2014.06.324

DO - 10.1016/j.proeng.2014.06.324

M3 - Conference article

AN - SCOPUS:84949134228

VL - 79

SP - 153

EP - 159

JO - Procedia Engineering

JF - Procedia Engineering

SN - 1877-7058

ER -