Time and temperature dependent mechanical behavior of HFPE-II-52 polyimide at high temperature

Xu, Yadong; Bhargava, Peeyush; Zehnder, Alan T.

doi:10.1016/j.mechmat.2016.06.009

Cited by 13 publications

(3 citation statements)

References 25 publications

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“…The surfaces tested are cut from a 0.5 mm-thick polyimide film and used as received from the supplier (UPILEX). Polyimides are used safely in extreme thermomechanical and chemical conditions, thanks to their high glass transition temperature and low creep properties [21]. Practical uses of polyimide films include electronic circuits, wire insulations, and composite components in aero-engines, turbine blades, and launch vehicles [22][23][24][25].…”

Section: Methodsmentioning

confidence: 99%

Experimental Investigation of Energy Dissipation in Presliding Spherical Contacts Under Varying Normal and Tangential Loads

Usta

Shinde

Eriten

2017

Journal of Tribology

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Interfacial damping in assembled structures is difficult to predict and control since it depends on numerous system parameters such as elastic mismatch, roughness, contact geometry, and loading profiles. Most recently, phase difference between normal and tangential force oscillations has been shown to have a significant effect on interfacial damping. In this study, we conduct microscale (asperity-scale) experiments to investigate the influence of magnitude and phase difference of normal and tangential force oscillations on the energy dissipation in presliding spherical contacts. Our results show that energy dissipation increases with increasing normal preload fluctuations and phase difference. This increase is more prominent for higher tangential force fluctuations, thanks to larger frictional slip along the contact interface. We also show that the energy dissipation and tangential fluctuations are related through a power law. The power exponents we identify from the experiments reveal that contacts deliver a nonlinear damping for all normal preload fluctuation amplitudes and phase differences investigated. This is in line with the damping uncertainties and nonlinearities observed in structural dynamics community.

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Section: Methodsmentioning

confidence: 99%

Experimental Investigation of Energy Dissipation in Presliding Spherical Contacts Under Varying Normal and Tangential Loads

Usta

Shinde

Eriten

2017

Journal of Tribology

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Section: Introductionmentioning

confidence: 99%

“…The mechanical behaviour of PMR15 and its composites has been particularly well characterised [21][22][23][24], while recently, experimental results on HFPE52 have also been reported [40]. In particular, the stress-strain curves of the two polyimides that have been characterised, among others, by [23] and [40], throw up subtle differences. The experimentally obtained uniaxial tensile responses for PMR15 at strain rates ranging between 10 10 s  = --˙, both have a comparable yield stress of around 35 45 MPa -, the stress carrying capacity of HFPE52 being somewhat lower than PMR15.…”

Section: Introductionmentioning

confidence: 99%

Mechanical response of two polyimides through coarse-grained molecular dynamics simulations

Sudarkodi

Sooraj

Nair

et al. 2018

Modelling Simul. Mater. Sci. Eng.

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Coarse-grained molecular dynamics (MD) simulations allow us to predict the mechanical responses of polymers, starting merely with a description of their molecular architectures. It is interesting to ask whether, given two competing molecular architectures, coarse-grained MD simulations can predict the differences that can be expected in their mechanical responses. We have studied two crosslinked polyimides PMR15 and HFPE52—both used in high- temperature applications—to assess whether the subtle differences in their uniaxial stress–strain responses, revealed by experiments, can be reproduced by carefully coarse-grained MD models. The coarse graining procedure for PMR15 is outlined in this work, while the coarse grain forcefields for HFPE52 are borrowed from an earlier one (Pandiyan et al 2015 Macromol. Theory Simul. 24 513–20). We show that the stress–strain responses of both these polyimides are qualitatively reproduced, and important insights into their deformation and failure mechanisms are obtained. More importantly, the differences in the molecular architecture between the polyimides carry over to the differences in the stress–strain responses in a manner that parallels the experimental results. A critical assessment of the successes and shortcomings of predicting mechanical responses through coarse-grained MD simulations has been made.

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Moisture Degradation Effects on the Mechanical Properties of HFPE-II-52 Polyimide: Experiments and Modeling

Zehnder

2017

Exp Mech

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Time and temperature dependent mechanical behavior of HFPE-II-52 polyimide at high temperature

Cited by 13 publications

References 25 publications

Experimental Investigation of Energy Dissipation in Presliding Spherical Contacts Under Varying Normal and Tangential Loads

Experimental Investigation of Energy Dissipation in Presliding Spherical Contacts Under Varying Normal and Tangential Loads

Mechanical response of two polyimides through coarse-grained molecular dynamics simulations

Moisture Degradation Effects on the Mechanical Properties of HFPE-II-52 Polyimide: Experiments and Modeling

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