Dynamic pressure control in VARTM: Rapid fabrication of laminates with high fiber volume fraction and improved dimensional uniformity

2018 ◽  
Vol 40 (6) ◽  
pp. 2482-2494 ◽  
Author(s):  
M. Akif Yalcinkaya ◽  
E. Murat Sozer ◽  
M. Cengiz Altan
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Dynamic Pressure ◽  
Pressure Control ◽  
Fiber Volume ◽  
High Fiber ◽  
Rapid Fabrication ◽  
Dimensional Uniformity

A Novel Model for Predicting the Thermal Conductivity of Fiber Reinforced Ceramic Materials

2014 ◽  
Vol 936 ◽  
pp. 154-163
Author(s):  
Rui Xu ◽  
Jun Kui Mao ◽  
Jing Yu Zhang ◽  
De Cang Lou ◽  
Wen Guo
Keyword(s):  
Thermal Conductivity ◽  
Volume Content ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Good Precision ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
High Fiber ◽  
Novel Model ◽  
Thermal Conductivities

The prediction of fiber reinforced ceramic is one of the most important procedure when investigating the application of ceramic composite. Numerical simulations were applied and a novel model was brought out in this paper. Firstly, four different models for predicting thermal conductivities of unidirectional fiber reinforced materials were compared, which include the Rayleigh,LN,ST and TE model,. It shows that Rayleigh model and LN model have good precision only in low fiber volume content cases. There existed big differences between the experimental and numerical results if predicted the high fiber volume content with either these four models. Then a novel model based on LN model was studied with the correction of the representative volume element method. Further comparison results indicate that the error can be reduced as 55.6% with this novel model. At the same time, the longitudinal (k11) and transverse (k22) thermal conductivities predicted by the novel model were also analyzed. It was found thatk11had a linear relationship with fiber volume fraction and thermal conductivity ratio (p). Butk22had a nonlinear relationship with fiber volume fraction, which increased much greatly when fiber volume fraction increasing at high fiber volume fraction andp>1.

Simulation for Composite Forming Infusion from both inside and outside at same Time

2013 ◽  
Vol 329 ◽  
pp. 153-156
Author(s):  
Wei Xiao Du ◽  
Zhong De Shan ◽  
Feng Liu
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Fiber Volume ◽  
New Approach ◽  
High Fiber ◽  
Composite Forming ◽  
Filling Time ◽  
Infusion Method

Impregnation quality is vital to the whole composite. To improve it a new approach-infusion from both inside and outside at same time is supposed. Some comparison simulation studies, based on PAM-RTM software, are performed in this paper about the new composite forming method and traditional infusion method including flow behavior and filling time. Filling time via the two methods are compared, and the following results are obtained-It takes less time to fill the mold with infusion from both inside and outside at same time than traditional one; higher fiber volume fraction is, more favorable the new forming method is. The new infusion method is proved to be an effective and novel forming method about parts with high-thickness or high fiber content in composite forming area. The results will contribute to researches on the whole composite forming and bring prospect to provide more usages of three dimensional composites in high rank field.

Parametric Generation of Random Distribution of Fibers in Long-Fiber Reinforced Composites and Micromechanical FE Analysis

2010 ◽  
Vol 452-453 ◽  
pp. 117-120
Author(s):  
Zhen Qing Wang ◽  
Xiao Qiang Wang ◽  
Ji Feng Zhang ◽  
Song Zhou
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Fiber Volume Fraction ◽  
Random Distribution ◽  
Volume Fraction ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Parametric Generation ◽  
High Fiber ◽  
Damage Initiation

A method for the parametric generation of the transversal cross-section microstructure model of unidirectional long-fiber reinforced composite (LFRC) is presented in this paper. Meanwhile, both the random distribution of the fibers and high fiber volume fraction are considered in the algorithm. The fiber distribution in the cross-section is generated through random movements of the fibers from their initial regular square arrangement. Furthermore, cohesive zone element is introduced into modeling the interphase between the fiber and the matrix. All these processes are carried out by the secondary development of the finite element codes (ABAQUS) via Python language programming. Based on the model generated, micromechanical finite element analysis (FEA) is performed to predict the damage initiation and subsequent evolution of the composites. The results show that this technique is capable of capturing the random distribution nature of these composites even for high fiber volume fraction. Moreover, the results prove that a good agreement with the experimental results is found.

Molding of PBO fabric reinforced thermoplastic composite to achieve high fiber volume fraction

2013 ◽  
Vol 34 (6) ◽  
pp. 953-958 ◽  
Author(s):  
Anchang Xu ◽  
Limin Bao ◽  
Mitsuo Nishida ◽  
Atsuhiko Yamanaka
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Thermoplastic Composite ◽  
Fiber Volume ◽  
High Fiber

A novel algorithm for significantly increasing the fiber volume fraction in the reconstruction model with large fiber aspect ratio

2021 ◽  
pp. 152808372110320
Author(s):  
Zeyang Li ◽  
Zhao Liu ◽  
Yongbo Xue ◽  
Ping Zhu
Keyword(s):  
Aspect Ratio ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Volume ◽  
High Fiber ◽  
Fiber Aspect Ratio ◽  
Large Fiber ◽  
Reconstruction Model

Geometric reconstruction is an important precondition for the computational micromechanics analysis of chopped fiber reinforced composites. When fiber aspect ratio increases, the maximum fiber volume fraction in reconstruction model reduces rapidly because of jamming limit, which greatly limits the application of reconstruction methods. A novel algorithm is proposed to significantly increase the fiber volume fraction in the reconstruction model of the chopped fiber reinforced composites with large fiber aspect ratio. The algorithm is made up of two stages. At the first stage, fibers are packed into the sublayers of initial filling space to preliminarily design fiber orientation distribution. The unidirectional arrangement of fibers is adopted to achieve high fiber volume fraction. At the second stage, a new multi-step fiber shaking strategy is used to introduce randomness into reconstruction model. The high fiber volume fraction over 30% is achieved within the wide range of fiber aspect ratio from 50 to 200 while the results of the existing methods are not more than 10%, showing the remarkable increase of the fiber volume fraction under large fiber aspect ratio. The proposed algorithm is verified by the statistical results of the four representative microstructural characteristics from reconstruction model and realistic material.

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