A 3003-H14 aluminum alloy rod with 0.5 in. diameter is subjected to a 2000- lb tensile load. Calculate the resulting diameter of the rod. If the rod is sub- jected to a compressive load of 2000 lb, what will be the diameter of the rod? Assume that the modulus of elasticity is 10,000 ksi, Poisson’s ratio is 0.33, and the yield strength is 21 ksi.

Compare the engineering and true secant elastic moduli for the natural rubber in Example Problem 6.2 at an engineering strain of 6.0. Assume that the deformation is all elastic.

Estimate the transverse tensile strength of the concrete in Problem 12.6.

The frame of a space shuttle type vehicle must have a high yield strength and high stillness, and the most important design factor is weight. Of all the materials presented in this chapter, what material might be the most suitable for the frame of a space shuttle? Assume that there will be both tensile and compressive stresses. For a space shuttle, cost is not a limiting factor. (a) You can eliminate entire classes of materials from consideration with a brief statement about their unsuitability. (b) What material has the highest specific yield strength? Give the yield strength, specific gravity, specific yield strength, elastic modulus, and specific elastic modulus for this material. (c) What material has the highest specific elastic modulus? Give the yield strength, specific gravity, specific yield strength, elastic modulus, and specific elastic modulus for this material. (d) Compare the materials with the highest specific yield strength and highest specific elastic modulus for suitability in the space shuttle frame. (C) Discuss the suitability of the top-rated material for this design from the viewpoint of the ability to produce a frame.

A tensile test was performed on a metal specimen with a diameter of 1 2 inch and a gage length (the length over which the elongation is measured) of 4 inches. The dam were plotted on a load-displacement graph. P vs. L. A best-fit line was drawn through the points, and the slope of the straight-line portion was calculated to be P/L =1392 kips/in. What is the modulus of elasticity?

According to Figure 5-20, is ii possible to completely separate one of the four materials from the other three? Explain your answer.

In Example Problem 12.1, a uniaxial composite material is made into a circular rod Vbith a 1.27-cm diameter from 70 volume percent continuous carbon fibers and 30 volume percent epoxy. The rod is subject to an axial force of 100,000 N. The composite matcrial in Example Problem 12.1 is to be replaced with a less expensive composite made of 70 volume percent continuous E-glass fibers and 30 volume percent epoxy. The elastic moduli are 5 GPa for the epoxy resin and 72.4 GPa fos the E-glass. (a) Compare the elastic modulus, composite strain, fiber and matrix stresses, and density of this composite with the carbon epoxy composite in Example Problem 12.1. Usc the density of UHM carbon, and assume the density of the epoxy is 1.2g/cm3 . (b) Can both the E-glass fiber and matrix withstand the applied force?