a pressure vessel of 250-mm inner diameter and 6-mm wall thickness is fabricated from a 1.2-m section of spirally welded pipe AB and is equipped with two rigid end plates. the gage pressure inside the vessel is 2 MPa, and 45-kN centric axial forces P and P' are applied to the end plates. Determine a) the normal stress perpendicular to the weld b) the shearing stress parallel to the weld.

Respuesta :

Missing Diagram is attached.

Answer:

a) 21.43 MPa

b) -14.2 MPa

Explanation:

Given:

[tex]di = 250 mm = 0.25 m[/tex]

[tex]L = 1.2 m[/tex]

[tex]t = 6 mm = 0.006m[/tex]

[tex] d_o = d_i + 2t = 0.25+(2*0.006) => 0.262 m [/tex]

[tex]P_g = 2 mpa[/tex]

[tex]P = 45 KN [/tex]

[tex]Area, A = \frac{pi*(250+2(6)^2-(250)^2)}{4} = 4825.47 mm^2 [/tex]

Calculating the stresses:

[tex] Hoop stress = \frac{Pd}{2t} = \frac{2*250}{2(6)} [/tex]

= 41.667 MPa

[tex] Longitudinal stress, T_L= \frac{Pd}{4t} = \frca{2*250}{4*6}[/tex]

= 20.833 MPa

[tex] Axial stress, T_a= \frac{P}{A} = \frac{-45*10^3}{4825.47} [/tex]

-9.325 MPa

For stress along x axis:

Tx = Tl - Ta

= 20.83 - 9.325

= 11.5 MPa

[tex] Tavg = \frac{Tx+Ty}{2} => \frac{11.5+41.66}[/tex]

= 26.58 MPa

[tex]Tmax = \frac{Tx - Ty}{2} => \frac{11.5 - 41.66}{2}[/tex]

= -15.08 MPa

Mohr's circle angle = 2∅

= 2 * 35°

= 70°

a) for normal stress perpendicular to weld, we have:

Tx' = Tavg + Tmax (cos70°}

= 26.590 - 15.08(cos70°)

= 21.43 MPa

b) shearing stress parallel to weld:

= Tmax (sin70°}

= -15.08 sin70°

= -14.2 MPa

Ver imagen Chrisnando