1. Make a chart showing modulus E and density ρ. Apply a selection line of slope 1, corresponding to the index ρ/E, positioning the line so that six materials are left above it. What families do they...

1. Make a chart showing modulus E and density ρ. Apply a selection line of slope 1, corresponding to the index ρ/E, positioning the line so that six materials are left above it. What families do they belong to?

2. A material is required for a tensile tie to link the front and back walls of a barn to stabilize both. It must meet a constraint on strength and have as low an embodied energy as possible. To be safe, the material of the tie must have fracture toughness K_1c. 18 MPa m1 /2 . The relevant index is

Construct a chart of σ_y
plotted against Hmρ. Add the constraint of adequate fracture toughness, meaning K_1c. 18 MPa m^{1 /2}
, using a “Limit” stage. Then plot an appropriate selection line on the chart and report the three materials that are the best choices for the tie.