A cylindrical pipe with diameter d = 1.0 m is subject to internal pressure p = 5.0 MP a but it is free to expand along the length, so that only hoop stress σ = pd/2t is developed in the wall. Use Tables 1.3-1.4, a resistance factor ∅ = 0.25 and a load factor α = 1.0, i.e., the internal pressure has no variability. Do not consider those materials for which the required data is not available.

(a) What is the optimum orientation for the fibers?, and why?

(b) What is the required wall thickness and material type that yields the minimum thickness?

(c) What is the required wall thickness and material type for minimum weight?

(d) What is the required wall thickness and material type for minimum cost? Assume the following costs ($/kg) for the materials in Table 1.3, from left to right: 1.60, 3.20, 1.50, 5.80, 2.0, 2.0, and for the materials in Table 1.4, from left to right: 10.80, 10.80, 10.80, 15.00, 15.00, 15.00, 20.00, 20.00.