图 Georgialnsuitute ⊙Technolosy The evolution of structural materials 10 Strength-Density 50 BC 104 Ceramics Metals and glasses 103 Wrought Bronze Leather /to grain Bone Shell Gold 102 Natural materials Julius Caesar B频 Stone 10 Copper Brick Tin to grain Concrete Cork 0.1 0.0 0.01 0.1 10 100 Density.p (Mg/m3) 材料科学与工程学院 4 School of Materials Science and Engineering材料科学与工程学院 School of Materials Science and Engineering 4