Multiple Shape Memory Effect for Smart Helical Springs with Variable Stiffness over Time and Temperature

Baniasadi, Mahdi; Foyouzat, Alireza; Baghani, Mostafa

doi:10.1016/j.ijmecsci.2020.105742

Cited by 33 publications

(13 citation statements)

References 32 publications

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“…As seen in the results, ignoring the time-dependent properties of composite layer or foam core increases deviation in simulation particularly at higher impact energy levels. 33,34…”

Section: Discussionmentioning

confidence: 99%

Investigation of viscoelastic properties in composite sandwich panels subjected to low-velocity impact: Experimental and numerical approaches

Hosseinkhani

Ghavami

Haghighi‐Yazdi

et al. 2023

Jnl of Sandwich Structures & Materials

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This study investigates the effect of viscoelastic properties in the numerical modeling of foam-filled sandwich panels when their composite facesheets are exposed to low-velocity impact loading. A finite element (FE) model is developed using the software package of ABAQUS and used to investigate the effect of both considering and ignoring the time-dependent behavior of composite laminate facesheets as well as the foam core. Material constitutive equations, damage characteristics, and failure modes are defined in a FORTRAN user-subroutine VUMAT. To characterize the material behavior of both polyurethane foam and glass/epoxy composite material, a set of experimental tests are conducted under compression, tension, and stress relaxation modes. To validate the numerical results, low-velocity impact tests at two energy levels of 9.81 and 17 joules are carried out on sandwich panels with foam core. The results of numerical simulations are found to be in good agreement with the experimental test results. It is shown that ignoring the viscoelastic properties in the composite laminate and the foam core can lead to deviations of up to 7% and 25%, respectively, from experimental results. The analysis reveals that, ignoring the viscoelastic behavior along the fiber-direction in the composite facesheets does no change the results considerably. The viscoelastic properties perpendicular to the fibers, however, has a more noticeable effect on the results due to the prevalence of the properties of the polymeric resin in that direction.

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“…As seen in the results, ignoring the time-dependent properties of composite layer or foam core increases deviation in simulation particularly at higher impact energy levels. 33,34…”

Section: Discussionmentioning

confidence: 99%

Investigation of viscoelastic properties in composite sandwich panels subjected to low-velocity impact: Experimental and numerical approaches

Hosseinkhani

Ghavami

Haghighi‐Yazdi

et al. 2023

Jnl of Sandwich Structures & Materials

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“…26 Baghani et al further developed a thermo-viscohyperelasticity theory, which provides a powerful tool for designing the multi-SMPs with tunable mechanics. 27,28 al. utilized the phase transition approach to characterize the triple-SME in styrene-based SMPs and implemented a programmable self-deployed structure.…”

Section: Introductionmentioning

confidence: 99%

Spatially Heterogeneous Dynamics in Multi-Shape Memory Polymers Undergoing Broad Glass Transitions

Wang,

Li,

Zhang

et al. 2023

Macromolecules

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The purpose of this study is to present a nonequilibrium dynamic model for investigating the heterogeneous relaxation mechanism underlying the multi-shape memory effect (multi-SME) in amorphous polymers. By incorporating the concept of phase transition into the Gibbs−DiMarzio lattice model, a time-dependent hole distribution function is developed to characterize the heterogeneous dynamics and complex viscoelastic responses of multi-shape memory polymers (multi-SMPs) for the first time. The proposed formulation is employed in a multi-SME cycle under different thermomechanical loading histories. The excellent agreement between the numerical predictions and the available experimental results demonstrates the capability of the proposed approach to investigate dynamic heterogeneity and collective motion in multi-SMPs. The effects of the heating method, hole formation energy, and loading frequency on the relaxation spectrum and thermomechanical behavior of multi-SMPs are further investigated using the proposed model. It is found that the heterogeneous distribution and dynamical fluctuation of the holes in Nafion multi-SMPs lead to a broad glass transition range from 328 to 413 K. This study is expected to provide theoretical guidance for the design of amorphous polymers with tunable multi-SMEs, thereby facilitating practical applications.

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“…As an emerging class of smart polymers, shape memory polymers (SMPs) feature the ability to recover their permanent shapes from one (or multiple [1,2]) programmed temporary shape(s) when exposed to specific stimuli, such as heat [3][4][5] electricity [6,7], light [8,9], magnetic fields [10,11] and solvents [12]. Also, they can work in one cycle, called one-way SMPs or several reversible cycles, called two-way SMPs [13].…”

Section: Introductionmentioning

confidence: 99%

Constitutive Modeling of multi-stimuli-responsive shape memory polymers with multi-functional capabilities

Baniasadi

Yarali

Bodaghi

et al. 2021

International Journal of Mechanical Sciences

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Multiple Shape Memory Effect for Smart Helical Springs with Variable Stiffness over Time and Temperature

Cited by 33 publications

References 32 publications

Investigation of viscoelastic properties in composite sandwich panels subjected to low-velocity impact: Experimental and numerical approaches

Investigation of viscoelastic properties in composite sandwich panels subjected to low-velocity impact: Experimental and numerical approaches

Spatially Heterogeneous Dynamics in Multi-Shape Memory Polymers Undergoing Broad Glass Transitions

Constitutive Modeling of multi-stimuli-responsive shape memory polymers with multi-functional capabilities

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