Question

Spider silk is an impressive natural material with a specific strength greater than structural steel. Given a tensile strength of a particular spider silk as 1.2 x 103 MPa with a density of 1.3 Mg/m", calculate its specific strength and compare that result with the value for 1040 steel in the table below. Specific Strengths (Strength/Density) Specific strength mm (in.) Group Material Noncomposites 1040 steel" 2048 plate aluminum Ti-5Al-2.5Sna 9.9 X 10 (0.39 X 10") 16.9 X 10 (0.67 x 10) 19.7 x 10% (0.78 x 10) 6.4 X 10 (0.25 X 10) 77.2 x 106 (3.04 x 10) Epoxyb Composites E-glass (73.3 vol %) in epoxy (parallel loading of continuous fibers) Al2O3 whiskers (14 vol %) in epoxy C (67 vol %) in epoxy (parallel loading)" Kevlar® (82 vol %) in epoxy (parallel loading) Douglas fir, kiln-dried to 12% moisture (loaded in bending) 48.8 X 10(1.92 x 106) 76.9 X 10(3.03 X 106) 112 x 10" (4.42 x 10) 18.3 x 10" (0.72 x 10) Express your answer to three significant figures. VOALIvec o ? The specific strength of spider silk is times the specific strength of 1040 steel. er silk is

Answer 1

Ques) Specific strength = Tensile strength density _ 1.2x103 - 923.0769 1.3 = 923:0769. teden. KN-m = 94.095 5x10 mm:n = 94.0955X106 N . 9.9X106 = 9.5046 times specific strength of 1040 steel is [9.5046] times specific 1040 stel. specific strength strength of Csscanned with CamScanner