Fiber Bundle Testing Technology And Its Application In Performance Evaluation Of FRPs

Fiber reinforced composites are made from fiber material, such as glass fiber, carbon fiber, etc. and matrix material by means of wet winding, substrate material molded or pultrusion molding process. Carbon fiber reinforced composite materials have been widely used in sailing, aerospace,automobile and apparatus, due to its high strength and high stiffness. The contact place of fiber and matricx form a interface by means of Physical or chemical reaction. Because the interface between the fiber and the matrix properties cannot be measured directly, the bonding strength between fiber and matrix material is used in characterization of interface properties usually. The bonding between fiber and matrix plays a crucial role in mechanical properties of the fiber reinforced composites. The weak interface layer between fiber and matrix cannot transfer the load effectively which cause the interface layer stress concentration. The Premature failure of interface affects the ultimate performance of the fiber reinforced composites.In this paper, a developed fiber bundle composites testing technology was used to test the strength of the interfacial bonding between T700 carbon fiber and E51 epoxy resin. The developed fiber bundle composites testing technology was used to simulate transverse tensile experiment and shearing experiment of the unidirectional laminates. By comparing the interface strength test results of fiber bundle composites and unidirectional composite laminates and the failure pattern, a relationship was established between the results of fiber bundle composites and the results of unidirectional laminates mechanics experiments. Based on the theory, the results of fiber bundle tests can be used to assess or predict the interface mechanical properties of corresponding unidirectional laminates.