# mechanics of materials

posted by .

A mild steel bar of width 10mm is subjected to a tensile stress of 3,0x105 Pa. Given that Young’s modulus for mild steel is 200 GPa and Poisson’s ration for mild steel is 0.31, calculate the change in width of the bar. Is the width increased or reduced?

• mechanics of materials -

I suggest you review the definition of Poisson's ratio at
http://www.engineeringtoolbox.com/poissons-ratio-d_1224.html

It is the ratio of the transverse strain to the longitudinal strain, with a minus sign stuck on. If a material gets stretched in uniaxial tension, it simultaneously gets thinner in the two perpendicular directions.

In your case, the strain along the direction of the applied tensile force is
dL/L = Stress/E = 3*10^5/200*10^9
= 1.6^10^-6

For mild steel, the dimensionless strain contraction in width is 0.31 times that number, or 4.65*10^-7.
That gets multiplied by 10 mm for the actual width reduction: 4.65*10^-6 mm

## Similar Questions

1. ### mechanical properties of materials

A cylindrical steel bar is required to support a load of 650 N. the required bar must be 0.17 m in length and must not deform by more than 0.015 mm. given that the Young's modulus of steel is 210 GPa, calculate the minumum diameter …
2. ### mechanical properties of materials

A cylindrical steel bar is required to support a load of 650 N. the required bar must be 0.17 m in length and must not deform by more than 0.015 mm. given that the Young's modulus of steel is 210 GPa, calculate the minumum diameter …
3. ### mechanics of materials

A steel bar with a cross sectional area of 25cm2 is found to shear fracture when subjected to a tensile load of 400kN. calculate the limiting shear stress of the bar.
4. ### mechanics of materials

A steel bar with a cross sectional area of 25cm2 is found to shear fracture when subjected to a tensile load of 400kN. calculate the limiting shear stress of the bar.
5. ### mechanics of materials

Select the correct answer.The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using: A. A different material having a Young's modulus half that of steel B half the cross …
6. ### mechanics of materials

The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using:which of the following is correct A. a different material having a Young's modulus half that of steel B half …
7. ### mechanics of materials

a mild steel bar of length 10cm and width of 10mm is extended by 0.01 mm. Which of the following is equal to the change in width of the bar.(The Poisson's ratio of mild steel is 0.31) A 3.1x10-4mm B -3.1x10-4mm C 3.1x10-5mm D -3.1x10-5mm
8. ### mechanics

A mild steel bar of length 10cm and width of 10mm is extended by 0.01 mm. Which of the following is equal to the change in width of the bar.(The Poisson's ratio of mild steel is 0.31) A 3.1x10-4mm B -3.1x10-4mm C 3.1x10-5mm D -3.1x10-5mm
9. ### Physics

Composite bar with end load (two segments) The composite bar BCD in the figure is composed of an inner aluminum cylindrical core of length 2L=2 m and radius R=1 cm and a sleeve of steel of length L=1 m and thickness R=1 cm surrounding …
10. ### physics

A strip of rubber originally 75 mm long is stretched until it is 100 mm long. a.What is the tensile strain b.Why has the answer no units?

More Similar Questions