A thermodynamically consistent continuum damage model for time-dependent failure of thermoplastic polymers

Khaleghi, Hassan; Amiri-Rad, Ahmad; Mashayekhi, ‪Mohammadreza

doi:10.1016/j.ijplas.2022.103278

Cited by 16 publications

(2 citation statements)

References 66 publications

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“…Mechanical response of a semicrystalline polymer is a complex process, including the cooperative and simultaneous evolution of an amorphous and a crystalline component. − At temperatures, above the glass-transition temperature of the polymer, the initial stage of deformation takes place within the amorphous layers. This is the effect of the differences in stress required to activate the deformation of the amorphous and crystalline component (10–50 times higher in crystals than that in the amorphous phase). − Three basic mechanisms of response of the amorphous component activated in different regions of the hierarchical structure of crystallizing polymers as a result of different orientation of the lamellae with respect to the deformation direction were described: separation of lamellae, interlamellar slips and rotation of lamellae stacks. − …”

Section: Introductionmentioning

confidence: 99%

Plastic Deformation of Polypropylene Studied by Positron Annihilation Lifetime Spectroscopy

et al. 2022

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In this work, positron annihilation lifetime spectroscopy (PALS) was used for the first time to study the plastic deformation of polypropylene. An appropriate methodological approach was proposed in order to analyze the mechanical response of polypropylene in a way similar to the in situ conditions. It was demonstrated that the intermediate lifetime expressed by the τ2 (mean positron lifetime) and σ2 (dispersion) values gives us information about the crystalline component while the longest lifetime was expressed by the τ3 (mean ortho-positronium lifetime) and σ3 (dispersion) about the “porosity” of the amorphous phase. Then, the influence of the polypropylene microstructure (thickness/perfection of lamellar crystals) and the cavitation phenomenon (cavitating/non-cavitating material) on the deformation process in the context of PALS data were analyzed/discussed. Among others, the process of relative slips of crystalline blocks within individual lamellae was detected even at very low strains. The simultaneous use of PALS and volume strain measurements confirmed the deformation-induced changes in the shape of free volume pores of the amorphous phase from isotropic (spherical) to anisotropic (ellipsoidal). The use of PALS and X-ray measurements also allowed us to estimate the initial shape of cavitation pores characterized by an aspect ratio exceeding 50.

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Section: Introductionmentioning

confidence: 99%

Plastic Deformation of Polypropylene Studied by Positron Annihilation Lifetime Spectroscopy

et al. 2022

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“…A capable simulation tool for fatigue must include a capable constitutive and fatigue damage model. Recent ambitious constitutive models for large deformations (without fatigue) are presented in [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. For the investigation of both low- and high-cycle fatigue regimes in highly crystalline and semi-crystalline polymers, References [ 10 , 19 ] provided capable tools based on a hyperelastic–viscoplastic model and an elastic viscoplastic (parallel rheological network) model, respectively.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Short- to Long-Term Cyclic Deformation Behavior and Fatigue Life of Polymers

Barriere,

Carbillet,

Gabrion

et al. 2024

Polymers

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The prediction of mechanical behavior and fatigue life is of major importance for design and for replacing costly and time-consuming tests. The proposed approach for polymers is a combination of a fatigue model and a governing constitutive model, which is formulated using the Haward–Thackray viscoplastic model (1968) and is capable of capturing large deformations. The fatigue model integrates high- and low-cycle fatigue and is based on the concept of damage evolution and a moving endurance surface in the stress space, therefore memorizing the load history without requesting vague cycle-counting approaches. The proposed approach is applicable for materials in which the fatigue development is ductile, i.e., damage during the formation of microcracks controls most of the fatigue life (up to 90%). Moreover, damage evolution shows a certain asymptote at the ultimate of the low-cycle fatigue, a second asymptote at the ultimate of the high-cycle fatigue (which is near zero), and a curvature of how rapidly the transition between the asymptotes is reached. An interesting matter is that similar to metals, many polymers satisfy these constraints. Therefore, all the model parameters for fatigue can be given in terms of the Basquin and Coffin–Manson model parameters, i.e., satisfying well-defined parameters.

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A temperature/strain-rate-dependent finite deformation constitutive and failure model for solid propellants

Lei,

Chen,

Zhao

et al. 2023

Sci. China Phys. Mech. Astron.

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A thermodynamically consistent continuum damage model for time-dependent failure of thermoplastic polymers

Cited by 16 publications

References 66 publications

Plastic Deformation of Polypropylene Studied by Positron Annihilation Lifetime Spectroscopy

Plastic Deformation of Polypropylene Studied by Positron Annihilation Lifetime Spectroscopy

Prediction of Short- to Long-Term Cyclic Deformation Behavior and Fatigue Life of Polymers

A temperature/strain-rate-dependent finite deformation constitutive and failure model for solid propellants

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