Compare the main advantages and disadvantages of fiberglass, carbon fiber and aramid fiber
(1) In terms of tensile strength, the glass fiber board is the lowest, the carbon fiber board is up to 3000~5000MPa, and the aramid fiber can also produce more than 3000MPa in recent years; the aramid fiber is the worst heat resistance of the organic fiber; the glass fiber The lowest cost; glass fiber and carbon fiber are brittle fibers, which are slightly inferior in processing and weaving, and the aramid fiber has good toughness and is easy to weave.
(2) In terms of tensile strength and modulus, carbon fiber CF > aramid KF > glass fiber GF, but the elongation at break of CF is small, sometimes not satisfactory. Density GF>CF>KF. The advantage of glass fiber is that it is cheaper and much cheaper than carbon fiber and aramid. The outstanding feature of aramid is its impact resistance, which can be used as a bulletproof garment, but the aramid is easy to absorb moisture.
(3) Advantages of aramid fiber compared with carbon fiber:
a, aramid fiber is not conductive (carbon fiber conductive). In addition, carbon fiber is used to reinforce concrete structures and must be isolated from steel bars to prevent electrochemical corrosion. The use of aramid fibers is not subject to this limitation.
b. The carbon fiber cloth has low shear strength and is easy to break. This makes the chamfering treatment requirement higher during construction. The chamfer radius is not less than 20mm, and the aramid fiber only needs 10mm.
c. The high elastic modulus of carbon fiber makes it able to withstand long-term static load, which is its most outstanding advantage, and aramid fiber is more competitive for dynamic load and local impact.
d. Carbon fiber has certain advantages compared with aramid fiber cloth when used to limit the deflection of the beam, but aramid fiber is undoubtedly a more suitable material in terms of operability of construction.
e. The failure mode after carbon fiber reinforcement is brittle (small structure deformation, small limit elongation of carbon fiber cloth), and there is no obvious sign. Therefore, as a structural design, a large safety factor must be adopted.