Bending Failure Behavior of the Glass Fiber Reinforced Composite I-Beams Formed by a Novel Bending Pultrusion Processing Technique

Abstract

The glass fiber reinforced resin matrix composite I-beams were designed and formed via a type of novel bending pultrusion processing technique, and the three-point bending tests were carried out to analyze the mechanical bending performances. The obtained results show that the main failure mode of the composite I-beam under the bending load is the upper structure (top flange) cracks along the length direction of the fibers, and the cracks simultaneously propagate downwards in the vertical direction. The bifurcated cracks can be found at the junction area between the top flange and web. In addition, the main bending failure mechanism of the composite I-beam includes the matrix cracking, propagation of cracks, and final fracture failure. In particular, noting that when the crack reaches the I-shaped neck position, the lateral bifurcation occurs, and the resulting secondary cracks further extend in two directions, which leads to the serious damage between the top flange and web, and the ultimate fracture failure occurs.

The tensile properties and repair behavior of glass fiber reinforced polymer using resin pre-coating technology

“…5 Some composite structures and components are large in size and high in cost, which will inevitably lead to defects or damage during manufacture and transportation, so can only be reduced use or even scrap. [6][7][8] The fabrication method of composite laminates using prepreg is more likely to cause micro-cracks between the layers, which may lead to delamination. The service life of composite materials is largely related to the internal structure of materials, due to surface contact or impact of foreign objects, which may be in the interface between the cracks or delamination.…”