engineering matreials

Assignment 3

1. Determine the material index for following problem. (20 points)

Floor joist beam with strong enough and minimum cost is required.

2. Material index examples in CH 5 (PowerPoint #27) showed that it need to draw the line with slop of 3 (PowerPoint #30) on Modulus-Density graph when material index is

Prove this is true. (20 points)

3. Explain why ductile metallic material is getting thinner in transverse direction when it is elongated in loading direction. Your answer should include entire mechanism of plastic deformation. (30 points)

4. E6.4, E6.5, E6.6 (30 points)

Figure 5.15