1). Low elastic modulus
The elastic modulus of FRP is twice larger than that of wood, but 10 times smaller than that of steel (E=2.1×106), so it often feels insufficient rigidity in the product structure and is easy to deform. It can be made into a thin shell structure, a sandwich structure, and can also be compensated by high-modulus fibers or reinforcing ribs.
2). Poor long-term temperature resistance
Generally, FRP cannot be used for a long time at high temperature. The strength of general-purpose polyester FRP decreases significantly when it is above 50 °C, and it is generally only used below 100 °C; general-purpose epoxy FRP is above 60 °C, and the strength decreases significantly. However, high temperature resistant resin can be selected, so that the long-term working temperature is possible at 200~300℃.
3). Aging phenomenon
Aging is a common defect of plastics, and FRP is no exception. It is easy to cause performance degradation under the action of ultraviolet rays, wind, sand, rain and snow, chemical media, and mechanical stress.
4). Low interlaminar shear strength
The interlaminar shear strength is borne by the resin, so it is very low. The interlayer adhesion can be improved by selecting a process and using a coupling agent. The most important thing is to avoid shearing between the layers as much as possible during product design.