Respuesta :
Answer:
Final diameter = 1.0032 m
Final length =3.0027 m
Explanation:
Given that
P= 15 MPa
r= 0.5 m
L= 3 m
t=10 mm
For A-36 steel ,modulus of elasticity = 200 GPa
Hoop stress
[tex]\sigma _h=\dfrac{Pd}{2t}[/tex]
[tex]\sigma _h=\dfrac{15\times 1}{2\times 0.01}[/tex]
[tex]\sigma _h=750 \ MPa[/tex]
Longitudinal stress
[tex]\sigma _l=\dfrac{Pd}{4t}[/tex]
[tex]\sigma _l=\dfrac{15\times 1}{4\times 0.01}[/tex]
[tex]\sigma _l=375 \ MPa[/tex]
Hoop strain
[tex]\varepsilon _h=\dfrac{\sigma _h}{E}-\mu \dfrac{\sigma _l}{E}[/tex]
Take μ=0.26
[tex]\varepsilon _h=\dfrac{750}{200\times 1000}-0.26\times \dfrac{375}{200\times 1000}[/tex]
[tex]\varepsilon _h=0.0032[/tex]
[tex]\varepsilon _h=\dfrac{\Delta d}{d}[/tex]
[tex]0.0032=\dfrac{\Delta d}{1}[/tex]
[tex]\Delta d=0.0032[/tex]
[tex]d_f=1+0.0032\ m[/tex]
Final diameter = 1.0032 m
Longitudinal strain
[tex]\varepsilon _l=\dfrac{\sigma _l}{E}-\mu \dfrac{\sigma _h}{E}[/tex]
[tex]\varepsilon _l=\dfrac{375}{200\times 1000}-0.26\times \dfrac{750}{200\times 1000}[/tex]
[tex]\varepsilon _l=0.0009[/tex]
[tex]\varepsilon _l=\dfrac{\Delta L}{L}[/tex]
[tex]0.0009=\dfrac{\Delta L}{3}[/tex]
So the final length = 3.0027 m