دانلود رایگان مقاله خواص کششی و نسبت شبیه سازی متقاطع همسانگرد ناپیوسته گرمانرم فیبر کربن

Abstract

Discontinuous carbon fiber reinforced thermoplastics (DCFRTPs) are regarded as potential substitutes for metallic materials used in the mass production of automotive parts. For predicting the mechanical properties of these composite materials, the analytical homogenization method as Mori-Tanaka model is one of the most efficient and accurate approaches, but the application of this model is limited because both the aspect ratio of the fibers and their volume fraction in the composite have to be low. In the present study, the tensile properties of two transversely isotropic DCFRTPs, carbon fiber mat reinforced thermoplastics (CMT), and ultra-thin chopped carbon fiber tape reinforced thermoplastics (UT-CTT), were investigated experimentally and analytically. The components and structural properties were evaluated in detail. A comparison between the Mori-Tanaka simulations and the experimental results showed a difference in the trends of the present results from those reported previously. In UT-CTT with a high volume fraction and high aspect ratio, the experimental results and the Mori-Tanaka model simulations were in good agreement. Conversely, a mismatch between the experimental and simulation results was observed in CMT with a wide aspect ratio distribution and low volume fraction. This difference in the predictive power of the Mori-Tanaka model for the two materials could be attributed to the difference in the microstructural regularity between CMT and UT-CTT. The effects of tape length on the tensile properties of UT-CTT were also studied.

5. Conclusions

In the present study, the tensile properties of two kinds of DCFRTPdCMT and UT-CTTdwere investigated experimentally and analytically. Analytical homogenization was conducted using the Mori-Tanaka model. The components and structural properties of the materials were measured in detail to ensure the accuracy of the simulation. The simulation results are different from those of previous researches that the Mori-Tanaka predictions showed good agreement with experimental results, even in materials with high Vf and high aspect ratios. However, the results are contradictory for different materials. The mismatch between the Mori-Tanaka estimations and experimental data is considered to be the result of structural irregularities, such as residual stress, due to the molding process and fiber curves in the material. The effects of tape length on the tensile properties of UT-CTT were predicted using the MoriTanaka model, and the optimal tape length can be calculated based on the predictions. Acknowledgements Research Fellowships of Japan Society for the Promotion of Science, Grant-in-Aid for JSPS Research Fellow Grant Number JP15J09248 support parts of this study. Part of this study was conducted as Japanese METI project “the Future Pioneering Projects/Innovative Structural Materials Project” since 2013 financial year. Authors would like to express sincerely appreciation to the project members who have provided valuable information and useful discussions.