| Abstract [eng] |
Interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) are important parameters for composite materials that characterize the load transfer between the matrix and the fiber, as well as between individual layers. These experiments allow for the assessment of a material’s structural reliability and the nature of its failure mechanism. The aim of this work is to investigate IFSS and ILSS values and failure modes using glass, carbon, and aramid fibers at the micro-scale using microbond testing, and at the macro-scale using short-beam shear testing. Simulations of the microbond test were also performed to evaluate the influence of different droplet geometries, interfacial thickness, and the distance between knives on the interfacial shear strength. The results showed that the highest interfacial shear strength was observed with carbon fiber (42,06 MPa), followed by glass fiber (37,79 MPa), and the lowest IFSS was observed with aramid fiber (16,71 MPa). The interlaminar shear strength results for woven glass composites fall within the 16–17 MPa range, while the unidirectional glass composite exhibits a significantly lower ILSS value–6,712 MPa–possibly due to a mixed failure mode. The unidirectional carbon composite exhibits better ILSS values (19,77 MPa) than the twill-weave carbon composite (16,02 MPa). It was found that the interphase shear strength is influenced by the length of the embedded droplet, and the simulation provided additional insights into how the plate spacing and interphase thickness affect the stress distribution. |
