01.11.2021 Views

Timothy A. Philpot - Mechanics of materials _ an integrated learning system-John Wiley (2017)

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

p15.54 A thin-walled cylindrical pressure vessel of inside

diameter d = 36 in. is fabricated from a material with a tensile yield

strength of 40 ksi. The internal pressure in the cylinder is 1,600 psi.

Assuming that the material obeys the von Mises criterion of yielding,

and that there is to be a safety factor of 3.0 against yielding,

determine the necessary wall thickness remote from the ends of the

vessel.

p15.55 A thin-walled cylindrical pressure vessel of inside

diameter d = 500 mm and wall thickness t = 5 mm is fabricated

from a material with a tensile yield strength of 280 MPa. Determine

the maximum internal pressure p that may be used in the cylinder

according to

(a) the maximum-shear-stress theory.

(b) the maximum-distortion-energy theory.

p15.56 A solid 80 mm diameter circular shaft made of coldrolled

steel is subjected to the simultaneous action of a torque T =

19 kN · m, a bending moment M = 8.5 kN · m, and a compressive

axial force P = 250 kN. The cold-rolled steel has a yield strength of

s Y = 420 MPa, in both tension and compression. On the basis of

(a) the maximum-shear-stress theory and

(b) the maximum-distortion-energy theory,

is the shaft overstressed?

p15.57 A 75 mm diameter solid circular shaft rotating at 800 rpm

transmits 400 kW and carries a tensile axial force P = 140 kN. The

material that makes up the shaft has a tensile yield strength of s Y =

110 MPa. On the basis of

(a) the maximum-shear-stress theory and

(b) the maximum-distortion-energy theory,

is the shaft overstressed? State the factors of safety for each theory.

p15.58 A hollow circular shaft made of an aluminum alloy is

subjected to a bending moment M = 1.2 kN · m and a torque T. The

shaft has an outside diameter of 60 mm and an inside diameter of

40 mm. Assume that the aluminum alloy has a yield strength

s Y = 275 MPa. Use

(a) the maximum-shear-stress theory and

(b) the maximum-distortion-energy theory

to determine the value of the torque T so that the shaft does not fail

by yielding.

p15.59 A 3 in. diameter solid circular shaft made of stainless

steel is subjected to the simultaneous action of a torque T = 6.0 kip · ft,

a tensile axial force P = 55 kips, and a bending moment M. The

stainless steel has a yield strength of s Y = 36 ksi, in both tension

and compression. Use

(a) the maximum-shear-stress theory and

(b) the maximum-distortion-energy theory

to determine the value of the moment M so that the shaft does not

fail by yielding.

p15.60 A solid circular shaft made of steel is subjected to a

torque T = 780 lb · ft and a tensile axial force P = 13,500 lb. Assume

that the steel has a yield strength s Y = 30,000 psi. Use

(a) the maximum-shear-stress theory and

(b) the maximum-distortion-energy theory

to determine the required diameter of the shaft so that the shaft does

not fail by yielding.

p15.61 The stresses on the surface of a machine component will

be in a state of plane stress with s x = s y = −40 ksi and τ xy = 85 ksi.

The ultimate failure strengths for the material that the component is

made of are 100 ksi in tension and 190 ksi in compression. Use the

Mohr failure criterion to determine whether this component is safe

for the state of stress given. Support your answer with appropriate

documentation.

p15.62 The stresses on the surface of a machine component

will be in a state of plane stress with s x = 510 MPa, s y = −140 MPa,

and τ xy = 375 MPa. The ultimate failure strengths for the material

that the component is made of are 700 MPa in tension and 420 MPa

in compression. Use the Mohr failure criterion to determine

whether this component is safe for the state of stress given. Support

your answer with appropriate documentation.

p15.63 The state of stress at a point in a cast iron [s UT = 290 MPa; s

UC = 650 MPa] component is s x = 0, s y = −180 MPa, and τ xy = 200

MPa. Determine whether failure occurs at the point according to (a)

the maximum-normal-stress theory and (b) the Mohr failure criterion.

666

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!