A pipe is subjected to a tension force of P = 90 kN. The pipe outside diameter is 45 mm, the wall thickness is 5 mm, and the elastic modulus is E = 150 GPa. Determine the normal strain in the pipe. Express the strain in mm/mm.

Respuesta :

Answer:

The strain is [tex]1.79\times10^{-3}[/tex]

Explanation:

Given that,

Force = 90 kN

Outside diameter = 45 mm

Thickness = 5 mm

Elastic modulus = 150 GPa

We need to calculate the inner diameter

Using formula of inner diameter

[tex]D_{in}=D_{o}-t[/tex]

Where, t = thickness

Put the value into the formula

[tex]D_{in}=45-5[/tex]

[tex]D_{in}=40\ mm[/tex]

We need to calculate the area of the pipe

Using formula of area

[tex]A=\dfrac{\pi}{4}(D_{o}^2-D_{in}^2)[/tex]

Put the value into the formula

[tex]A=\dfrac{\pi}{4}((45)^2-(40)^2)[/tex]

[tex]A=333.79\ mm^2[/tex]

We need to calculate the stress

Using formula of stress

[tex]\sigma=\dfrac{P}{A}[/tex]

Put the value into the formula

[tex]\sigma=\dfrac{90\times10^{3}}{333.79}[/tex]

[tex]\sigma=269.63\ N/mm^2[/tex]

We need to calculate the strain in the pipe

Using formula of elastic modulus

[tex]E=\dfrac{stress}{strain}[/tex]

Put the value into the formula

[tex]150\times10^{3}=\dfrac{269.63}{strain}[/tex]

[tex]strain=\dfrac{269.63}{150\times10^{3}}[/tex]

[tex]strain=0.00179[/tex]

[tex]strain=1.79\times10^{-3}[/tex]

Hence, The strain is [tex]1.79\times10^{-3}[/tex]

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