Characterization of nonlinear viscoelastic behavior using a dynamic mechanical approach

The increased use of fiber reinforced plastics (FRPs) in ship topside structures necessitates the need to understand how such structures respond to fire exposure. For this reason we have characterized the nonlinear, thermo-viscoelastic behavior of Vetrotex 324∕Derakane 510A-40 using tensile loading of [±45]2S laminates. Nonlinearity is observed at elevated stress and temperatures above Tg. The data reduction sufficiently modeled the experimental master-curves over the whole temperature range, but suffered from inconsistencies in the creep data and recovery data, perhaps due to accumulated damage during the creep cycle. Our results indicate that the nonlinear viscoelastic behavior significantly contributes to structural behavior under fire loading conditions.

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Scaling relations in nonlinear viscoelastic behavior of aqueous PEO solutions under large amplitude oscillatory shear flow

Journal of Rheology ◽

10.1122/1.3258278 ◽

2010 ◽

Vol 54 (1) ◽

pp. 27-63 ◽

Cited By ~ 41

Author(s):

Kwang Soo Cho ◽

Ki-Won Song ◽

Gap-Shik Chang

Keyword(s):

Shear Flow ◽

Large Amplitude ◽

Viscoelastic Behavior ◽

Oscillatory Shear ◽

Scaling Relations ◽

Large Amplitude Oscillatory Shear ◽

Oscillatory Shear Flow ◽

Nonlinear Viscoelastic ◽

Nonlinear Viscoelastic Behavior

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Introduction to Nonlinear Viscoelastic Behavior: Creep

Elastic And Inelastic Stress Analysis ◽

10.1201/b16599-10 ◽

1997 ◽

pp. 218-263

Keyword(s):

Viscoelastic Behavior ◽

Nonlinear Viscoelastic ◽

Nonlinear Viscoelastic Behavior

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Role of smooth muscle activation in the static and dynamic mechanical characterization of human aortas

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2117232119 ◽

2022 ◽

Vol 119 (3) ◽

pp. e2117232119

Author(s):

Giulio Franchini ◽

Ivan D. Breslavsky ◽

Francesco Giovanniello ◽

Ali Kassab ◽

Gerhard A. Holzapfel ◽

...

Keyword(s):

Experimental Data ◽

Smooth Muscle ◽

Muscle Activation ◽

Mechanical Response ◽

Mechanical Characterization ◽

Viscoelastic Behavior ◽

Material Model ◽

Suitable Material ◽

Dynamic Mechanical

Experimental data and a suitable material model for human aortas with smooth muscle activation are not available in the literature despite the need for developing advanced grafts; the present study closes this gap. Mechanical characterization of human descending thoracic aortas was performed with and without vascular smooth muscle (VSM) activation. Specimens were taken from 13 heart-beating donors. The aortic segments were cooled in Belzer UW solution during transport and tested within a few hours after explantation. VSM activation was achieved through the use of potassium depolarization and noradrenaline as vasoactive agents. In addition to isometric activation experiments, the quasistatic passive and active stress–strain curves were obtained for circumferential and longitudinal strips of the aortic material. This characterization made it possible to create an original mechanical model of the active aortic material that accurately fits the experimental data. The dynamic mechanical characterization was executed using cyclic strain at different frequencies of physiological interest. An initial prestretch, which corresponded to the physiological conditions, was applied before cyclic loading. Dynamic tests made it possible to identify the differences in the viscoelastic behavior of the passive and active tissue. This work illustrates the importance of VSM activation for the static and dynamic mechanical response of human aortas. Most importantly, this study provides material data and a material model for the development of a future generation of active aortic grafts that mimic natural behavior and help regulate blood pressure.

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