Three-dimensional finite element models and tensile properties of carbon fiber needled felt reinforced composites

Abstract

In this study, the three-dimensional finite element models of carbon fiber needled felt reinforced composites were built by using the embedded element technique and the virtual yarn method. Three sizes of samples for carbon fiber needled felt reinforced composites were designed and prepared. The tensile properties were investigated by experiments and theoretical methods, and the influences of sample size on tensile modulus were discussed. The results showed that, the longitudinal tensile moduli of carbon fiber needled felt reinforced composites decreased with the increase of sample size. Compared with the rule of mixtures and the inclusion theory, the longitudinal tensile moduli obtained by finite element method were closer to the experimental values. In addition, the transverse tensile moduli obtained by finite element method were greater than that obtained by the rule of mixtures and the inclusion theory. That was due to the orientation of some fibers had a proportion along the thickness. It was concluded that, these three-dimensional finite element models can be used to investigate the elastic properties of carbon fiber needled felt reinforced composites with different sizes.

Numerical and experimental analysis on anisotropic thermal conductivity of carding quartz fiber web based on the reconstruction model

“…Recent studies on the methods of constructing a 3D carding fiber web model (CFWM) mainly included the random sequential adsorption method (RSAM) [10][11][12][13][14][15] and the modified RSAM, 16 deposition method, [17][18][19] Monte Carlo method, 20,21 the forcebiased method 22,23 and reconstructed 3D model method based on the microcomputed tomography image. [24][25][26][27] However, the methods above [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] mainly aimed at establishing the short and straight fibers or the small slenderness ratio fibers to construct the fiber web model, the actual carding fiber web contains not only straight fibers but also curved LSRFs. 2,10 In comparison to the fiber aggregation with short-straight fibers and small slenderness ratio fibers, the carding fiber web with curved LSRFs (slenderness ratio more than 1000) imply the complex space geometry structure.…”

“…In addition, the finite element analysis on the performance of the fiber web focused on the mechanical properties of its composites, 12,[31][32][33] or aimed to simulate the needle-punched process. 34 Few studies 10,35 aimed to establish the 3D model of the carding fiber web containing LSRFs and analyze its detailed AHT (including temperature distribution (TD) and heat flux distribution (HFD)).…”

“…A 3D CFWM is assembled with a solid air model to form the two-phase composite model of heat transmission, and the AHT of the carding fiber web is further analyzed in detail. Compared with the methods mentioned above, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] the method proposed in this paper can not only obtain the detailed temperature and HFD, but also carry out the mechanical analysis of the CQFW and its composites efficiently and precisely. Moreover, compared with the models containing short and straight fibers mentioned above, the CQFW containing LSRFs in this paper can more clearly illustrate the relationship between the fiber orientation and HFD.…”

“…Due to the presence of the randomly distributed fibers and large slenderness ratio fibers (LSRFs) in the carding fiber web, it is difficult to construct the high-fidelity three-dimensional (3D) model of the CQFW. Recent studies on the methods of constructing a 3D carding fiber web model (CFWM) mainly included the random sequential adsorption method (RSAM) [10][11][12][13][14][15] and the modified RSAM, 16 deposition method, [17][18][19] Monte Carlo method, 20,21 the forcebiased method 22,23 and reconstructed 3D model method based on the microcomputed tomography image. [24][25][26][27] However, the methods above [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] mainly aimed at establishing the short and straight fibers or the small slenderness ratio fibers to construct the fiber web model, the actual carding fiber web contains not only straight fibers but also curved LSRFs.…”

I-fiber implantation robot for composite parts

“…After that, its strength will be significantly reduced in both the thickness and plane directions, leading to the loss of its ability in carrying structural loads. 1 In order to overcome the weak mechanical properties in the thickness direction, many effective strengthening methods, such as interlocking between layers, 2,3 z-pins, 4,5 tufting, 6–8 needle-punching, 9–12 traditional stitching 13,14 and nanotechnology, 15–17 have been studied. Moreover, in order to improve the interlayer properties of large-size, irregular shaped preforms or composites, researchers have invented robotic tufting, 18–20 robotic needle-punching 21,22 and robotic stitching technology.…”