Quasi-Disk Type Microbond Pull-Out Test for Evaluating Fiber/Matrix Adhesion in Composites

Abstract

Adhesion strength between epoxy resin and carbon fiber was analyzed using various microbond types adhered onto a single carbon fiber. Experimental pull-out tests were performed for a quasi-disk type, a hemispherical type and a droplet type microbond specimen. The quasi-disk type microbond specimen showed high regression coefficient and low standard deviation in the measurement of interfacial shear strength data as compared with the droplet and hemispherical ones. Average value of interfacial shear strength for quasi-disk type was about 55% as large as those for the other types. Finite element analysis showed that the stress distributions along the interface in the quasi-disk type specimen did not have such drastic stress concentrations susceptible to variations in the specimen geometry as revealed in the cases of droplet and hemispherical types. The experimental data were different according to the kinds of loading device such as the microvise-tip and the pin-holed plate. The use of a pin-holed steel section was useful for testing the quasi-disk type microbond specimens to give low scattering in the measurement of strength data.

A Finite Element Investigation into the Cohesive Properties of Glass-Fiber-Reinforced Polymers with Nanostructured Interphases

“…First, experimental pull-out tests were carried out to calculate the maximum pull-out load (Figure 2, entries 1 and 2, and Figure S3). As reported elsewhere [16], assuming a homogeneous stress distribution along the interface, the IFSS can be calculated as [36]:…”

“…Thus, the failure mechanism in composites can be fairly characterized by a fiber bundle pull-out test. In addition, the IFSS can be directly correlated with adhesion energy between the fiber and matrix, thus providing a characterization of the fiber to matrix interphase in GF-reinforced composites [16].…”

Fiber-Matrix Interface Characterization through the Microbond Test

“…The shear strength measured with this new cylindrical shaped droplet was higher than that obtained by the usual sample preparation method, along with a reduction in data scatter. A quasi-disk type microbond specimen for a carbon fiber-epoxy resin developed by Choi et al [54,55] was shown to have a lower standard deviation in IFSS compared to the droplet (ellipsoid) type specimens. The loading of the quasi-disk droplet is achieved by the microvise tips and a steel section as shown in Figure 4.…”

Fiber bias effect on characterization of carbon fiber-reinforced polymer composites by nanoindentation testing and modeling

“…15 Micromechanical modeling and experimental investigation of the microbond pull-out tests were conducted by pulling a fiber out of a quasi-disk type, a hemispherical type, or a droplet type matrix microbond specimen. [16][17][18][19][20] Nanomechanical imaging technique has been adopted for mapping the dynamic mechanical property around the interphase region. 21 Finite element analysis (FEA) model generation based on stochastic analysis on AFM images was used for fiber-matrix interphase or single fiber pull-out simulations.…”