Modeling the temperature dependent ultimate tensile strength of fiber/polymer composites considering fiber agglomeration

A temperature dependent ultimate tensile strength (TDUTS) model of polymer composites reinforced with fibers (FPCs) for a wide range of volume fractions was developed according to the Force-Heat Equivalence Energy Density Principle and combined with the Halpin-Tsai model. This model involved the quantitative evolution of thermo-physical performance of fiber, polymer with temperature, as well as the effects of fiber agglomeration, volume fraction, orientation and geometry. The predictive model was verified by comparing the predictions with the available experimental results of both short and unidirectional fiber/polymer composites for a wide range of temperature and volume fractions. To illustrate the effect of fiber agglomeration on the composite TDUTS, influencing factor analysis was also made. Compared with other classical models, this model predicts more accurate and only basic and easily accessible material parameters are required. This study demonstrates theoretical support to estimate the UTS of FPCs versus volume fractions at elevated temperatures, further provides opinion about the composite preparation and performance improvement.

Automated summary

A temperature dependent ultimate tensile strength model for polymer composites reinforced with fibers was developed based on the Force-Heat Equivalence Energy Density Principle and Halpin-Tsai model, showing accurate predictions with only basic material parameters needed. The model quantitatively describes the evolution of thermo-physical performance of fibers and polymers with temperature, and has been validated through comparison with experimental results for a wide range of conditions. Additionally, an analysis of the effect of fiber agglomeration on composite strength was conducted.