what property the fiberglass have?

A single structural glass fiber is both rigid and strong in the axial and axial directions. Although it can be assumed that the fiber's resistance to compression is weak, in fact only the fiber's aspect ratio makes it look like this. That is, since typical fibers are long and narrow, they are easy to bend. On the other hand, the shear strength of glass fiber is weak, that is, the shear strength along its axis is weak. Therefore, if the collection of fibers can be permanently arranged within the material in a preferred direction, and if they can be prevented from bending in compression, the material will preferably be strong in that direction.

In addition, by placing multiple layers of fibers on top of each other, with each layer facing a different preferred direction, the overall stiffness and strength of the material can be effectively controlled. In the glass fiber, the plastic matrix permanently restricts the structural glass fiber to the direction chosen by the designer. When using chopped stranded felt, this directionality is essentially the entire two-dimensional plane. For woven fabrics or unidirectional layers, the directionality of stiffness and strength can be controlled more accurately in the plane.

Fiberglass parts are usually thin "shell" structures, sometimes filled with structural foam, like surfboards. The part can have almost any shape, limited only by the complexity and tolerances of the mold used to make the housing.

The mechanical function of the material depends to a large extent on the comprehensive properties of the resin (AKA matrix) and fiber. For example, under severe temperature conditions (above 180°C), the resin component of the composite material may lose its function, partly due to the decrease in the bonding properties of the resin and the fiber. However, GFRP will still show significant residual strength after being subjected to high temperatures (200°C).