A diagonal aluminum alloy tension rod of diameter d and initial length l is used in a rectangular frame to prevent collapse. The rod can safely support a tensile stress of sallow. If d 5 0.5 in, l 5 8 ft, and sallow 5 20 kpsi, determine how much the rod must be stretched to develop this allowable stress.

Respuesta :

Answer:

[tex]\Delta L = 0.1883 inch[/tex]

Explanation:

Given data:

d = 0.5 inch

[tex]L_i = 8 ft[/tex]

[tex]\sigma_{allow} = 20  kpsi[/tex]

we know that change in length is given as

[tex]\Delta L = \frac{PL}{AE}[/tex]

              [tex]= \frac{P}{A}\times \frac{L}{E}[/tex]

              [tex]= \sigma_{allow} \times \frac{L}{E}[/tex]

modulus of elasticity E for aluminium alloy is [tex]10.2 \times 10^6 psi = 10.2 \times 10^3 kpsi[/tex]

[tex]\Delta L = \frac{20 \times 8}{10.2\times 10^3}[/tex]

[tex]\Delta L = 0.01569 ft[/tex]

[tex]\Delta L = 0.1883 inch[/tex]