# Modeling and Predicting the Stress Relaxation of Composites with Short and Randomly Oriented Fibers

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## Abstract

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## 1. Introduction

## 2. Analytical Model

## 3. Monte Carlo Finite Element Simulations

## 4. Results

## 5. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**The load carried by a fiber in the loading axis can be calculated through a cross-line perpendicular to the loading direction.

**Figure 2.**A comparison of the overall stress relaxation profile of short-fiber composites shows excellent agreement between the predictions of the analytical model (-) and the results obtained from the finite element experiments (■).

**Figure 3.**Comparison of the analytical model predictions to the finite element (FE) simulation results shows good agreement between the two at low volume fraction; however, at volume fractions equal to 30% and greater, the finite element results deviate from the predictions of the analytical model.

**Figure 4.**Good agreement is obtained between the instantaneous (

**a**) and long-term (

**b**) moduli values obtained from the analytical model (-) and the finite element simulations (●).

**Figure 5.**Good agreement is obtained between the relaxation rate constant obtained from the analytical model (-) and the finite element simulations (●).

**Figure 6.**Effect of fiber orientation on the properties of the composite as obtained from finite element experiments.

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**MDPI and ACS Style**

Obaid, N.; Kortschot, M.T.; Sain, M.
Modeling and Predicting the Stress Relaxation of Composites with Short and Randomly Oriented Fibers. *Materials* **2017**, *10*, 1207.
https://doi.org/10.3390/ma10101207

**AMA Style**

Obaid N, Kortschot MT, Sain M.
Modeling and Predicting the Stress Relaxation of Composites with Short and Randomly Oriented Fibers. *Materials*. 2017; 10(10):1207.
https://doi.org/10.3390/ma10101207

**Chicago/Turabian Style**

Obaid, Numaira, Mark T. Kortschot, and Mohini Sain.
2017. "Modeling and Predicting the Stress Relaxation of Composites with Short and Randomly Oriented Fibers" *Materials* 10, no. 10: 1207.
https://doi.org/10.3390/ma10101207