Young's modulus divided by density, E/ρ, also called specific modulus. Steel, aluminum alloys and titanium alloys are all roughly the same, at about 25 GPa/(g/cm³).
Japanese name: 比剛性
Specific stiffness appears in 1 practice question across 1 topic, including Composite materials.
Answer: C. CFRP excels in specific stiffness but conducts electricity, so it readily causes galvanic corrosion in contact with aluminum alloys
Carbon fiber has a density of about 1.8 g/cm³, lower than glass fiber (about 2.5 g/cm³), and a Young's modulus of about 230 GPa or more, over three times that of glass fiber (about 70 GPa), so CFRP excels in specific stiffness and specific strength and is used in aircraft and sporting goods. However, it is expensive, and because carbon fiber conducts electricity and has a noble electrode potential, contact with aluminum alloys readily causes galvanic corrosion of the aluminum; countermeasures include placing a layer of glass fiber between them. It is CFRP that conducts electricity, not GFRP. Transparency to radio waves and high insulation are characteristics of GFRP, which is used for radomes, electrical insulating parts, and inexpensive boat hulls and bathtubs.
Carbon fiber has a density of about 1.8 g/cm³, lower than glass fiber (about 2.5 g/cm³), and a Young's modulus of about 230 GPa or more, over three times that of glass fiber (about 70 GPa), so CFRP excels in specific stiffness and specific strength and is used in aircraft and sporting goods.
Which correctly compares carbon-fiber-reinforced plastic (C…CFRP (carbon-fiber-reinforced plastic) GFRP (glass-fiber-reinforced plastic) Young's modulus Galvanic corrosion Ashby chart (materials selection chart) Life cycle assessment Material index (performance index) Pareto optimality Tramp elements Yield before fracture