Molecular dynamics simulation based size and rate dependent constitutive model of polystyrene thin films

Yang, Fan; Ghosh, Somnath; Lee, L. James

doi:10.1007/s00466-012-0714-x

Cited by 15 publications

(10 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The size dependent mechanical properties of thin PS films are believed to come from the less configurational constraints at the surface and the resulted effect on atomic mobility. As stated in the literature [18,19], the near surface region has a lower density and a larger free volume, allowing for larger atomic mobility compared to the bulk region. In this section, we investigate the variation of local chain mobility along film thickness through the mean square displacement (MSD) and its components, especially under the deformation condition.…”

Section: Fig 2 Stress-strain Curves For Both the Bulk And Film Samplmentioning

confidence: 92%

See 1 more Smart Citation

Surface Effect on Mechanical Properties and Atomic Mobility of Ultrathin Polystyrene Films using Molecular Dynamics Simulations

Yang¹,

Zhong²

2017

Proceedings of the 2017 2nd International Conference on Materials Science, Machinery and Energy Engineering (MSMEE 2017)

Self Cite

View full text Add to dashboard Cite

Thin polystyrene film has shown anomalous properties such as reduced glass transition temperature when the thickness is below 100 nm. However, few attentions have been paid to its mechanical properties, which are important in understanding the stability and reliability of polymer nano-structures. In this work, we aim at elucidating the size dependent mechanical properties of ultrathin polystyrene films using molecular dynamics (MD) simulations. Coarse grained MD samples of free-standing PS films with different thicknesses were generated using the augmented phantom chain growth method. Active deformations were applied by moving two repulsive walls to determine the size dependent mechanical properties of the films. The distribution of local atomic mobility was investigated through partitioning the films into equidistant bins along thickness and calculating the mean square displacement for each bin. The results indicate the existence of a softened surface layer with reduced modulus and enhanced local atom mobility compared to the bulk state. It shows the deformation has an enhancing effect on the local atom mobility, especially along the thickness direction. This work can provide insights into the size dependent mechanical properties of ultrathin polymer films.

show abstract

Section: Fig 2 Stress-strain Curves For Both the Bulk And Film Samplmentioning

confidence: 92%

“…MD simulations, on the other hand, can be useful in understanding the size dependent properties of polymeric nanostructures from the bottom-up viewpoint. A number of researches [8,18,19] have been conducted using MD to investigate the polymer thin films, and obtained useful results.…”

Section: Introductionmentioning

confidence: 99%

Surface Effect on Mechanical Properties and Atomic Mobility of Ultrathin Polystyrene Films using Molecular Dynamics Simulations

Yang¹,

Zhong²

2017

Proceedings of the 2017 2nd International Conference on Materials Science, Machinery and Energy Engineering (MSMEE 2017)

Self Cite

View full text Add to dashboard Cite

show abstract

“…A cutoff distance of 12 Å is used for the non-bonded interactions. For the film samples, the repulsive interactions between the wall and the PS atoms are given by a LJ typed potential following the work by Yang et al (2012).…”

Section: Appendix a Supplementary Materialsmentioning

confidence: 99%

On the energy conservation during the active deformation in molecular dynamics simulations

Yang

Zhong

2015

Journal of the Mechanics and Physics of Solids

Self Cite

View full text Add to dashboard Cite

“…Polystyrene (PS), the polymer that is the subject of this study, is a typical thermoplastic polymer of which the characteristics include hyperelastic behavior, and many studies have been conducted to predict its mechanical behavior by using hyperelastic fitting. 4 This means that the typical constitutive equation described above cannot be used for hyperelastic materials and a new analysis is required to derive an appropriate formula. Therefore, a constitutive equation for hyperelastic polymers is often defined on the basis of parameters derived by differentiating the energy density function of the material because the energy function of a hyperelastic polymer consists of strain terms.…”

Section: Introductionmentioning

confidence: 99%

“…However, certain polymers exhibit different behavior characteristics, for example, nonlinear elastic behavior, and are termed hyperelastic materials. Polystyrene (PS), the polymer that is the subject of this study, is a typical thermoplastic polymer of which the characteristics include hyperelastic behavior, and many studies have been conducted to predict its mechanical behavior by using hyperelastic fitting 4 . This means that the typical constitutive equation described above cannot be used for hyperelastic materials and a new analysis is required to derive an appropriate formula.…”

Section: Introductionmentioning

confidence: 99%

A neural network constitutive model for hyperelasticity based on molecular dynamics simulations

Chung

Cho

2020

Numerical Meth Engineering

View full text Add to dashboard Cite

Numerical analysis of the hyperelastic behavior of polymer materials has drawn significant interest from within the field of mechanical engineering. Currently, hyperelastic models based on the energy density function, such as the Neo-Hookean, Mooney-Rivlin, and Ogden models, are used to investigate the hyperelastic responses of materials. Conventionally, constants relating to materials were determined from experimental data by using global least-squares fitting. However, formulating a constitutive equation to capture the complex behavior of hyperelastic materials was difficult owing to the limitations of the analytical model and experimental data. This study addresses these limitations by using a system of neural networks (NNs) to design a data-driven surrogate model without a specific function formula, and employs molecular dynamics (MD) simulations to calculate the massive amount of combined loading data of hyperelastic materials. Thus, MD simulations were used to propose an NN constitutive model for hyperelasticity to derive the constitutive equation to model the complex hyperelastic response. In addition, the probability distributions of the numerical solutions of hyperelasticity are used to characterize the uncertainty of the MD models. These statistical finite element results not only present numerical results with reliability ranges but also scattered distributions of the solution obtained from the MD-based probability distributions.

show abstract

Molecular dynamics simulation based size and rate dependent constitutive model of polystyrene thin films

Cited by 15 publications

References 50 publications

Surface Effect on Mechanical Properties and Atomic Mobility of Ultrathin Polystyrene Films using Molecular Dynamics Simulations

Surface Effect on Mechanical Properties and Atomic Mobility of Ultrathin Polystyrene Films using Molecular Dynamics Simulations

On the energy conservation during the active deformation in molecular dynamics simulations

A neural network constitutive model for hyperelasticity based on molecular dynamics simulations

Contact Info

Product

Resources

About