Simple Strain and Deformation — Worked Examples

The examples move from direct strain calculations to segmented and compatible axial systems. Unless stated otherwise, behavior is linear elastic.

1. Normal Strain from Measured Elongation

A 2.00 m2.00\text{ m} gauge length elongates by 2.00 mm2.00\text{ mm}. Determine the average normal strain.

Step-by-Step Solution

0 of 2 Steps Completed
1

2. Hooke's Law and Elongation

A steel bar is subjected to 120 MPa120\text{ MPa} tensile stress. Take E=200 GPaE=200\text{ GPa} and L=1.50 mL=1.50\text{ m}. Determine the strain and elongation.

Step-by-Step Solution

0 of 2 Steps Completed
1

3. Axial Deformation of a Prismatic Bar

A steel bar carries 80 kN80\text{ kN} in tension. Its length is 3.00 m3.00\text{ m}, area is 500 mm2500\text{ mm}^2, and E=200 GPaE=200\text{ GPa}. Determine the elongation.

Step-by-Step Solution

0 of 2 Steps Completed
1

4. Segmented Bar Deformation

A two-segment steel bar carries the same tensile force P=60 kNP=60\text{ kN} through both segments. Segment 1 has L1=1.0 mL_1=1.0\text{ m} and A1=400 mm2A_1=400\text{ mm}^2; Segment 2 has L2=1.5 mL_2=1.5\text{ m} and A2=600 mm2A_2=600\text{ mm}^2. Take E=200 GPaE=200\text{ GPa}. Find the total elongation.

Step-by-Step Solution

0 of 2 Steps Completed
1

5. Poisson Contraction

A 50 mm50\text{ mm} diameter steel bar is in uniaxial tension at 100 MPa100\text{ MPa}. Take E=200 GPaE=200\text{ GPa} and ν=0.30\nu=0.30. Determine the change in diameter.

Step-by-Step Solution

0 of 2 Steps Completed
1

6. Shear Modulus from E and Poisson's Ratio

For an isotropic linear-elastic material, E=200 GPaE=200\text{ GPa} and ν=0.30\nu=0.30. Determine GG.

Step-by-Step Solution

0 of 2 Steps Completed
1

7. Bulk Modulus from E and Poisson's Ratio

For the same material with E=200 GPaE=200\text{ GPa} and ν=0.30\nu=0.30, determine KK.

Step-by-Step Solution

0 of 2 Steps Completed
1

8. Compression and Sign Convention

An aluminum bar with A=800 mm2A=800\text{ mm}^2, L=1.20 mL=1.20\text{ m}, and E=70 GPaE=70\text{ GPa} carries a 56 kN56\text{ kN} compressive force. Determine its axial deformation using tension-positive signs.

Step-by-Step Solution

0 of 2 Steps Completed
1

9. Effect of Doubling Area

A prismatic elastic bar carries a fixed axial load with fixed LL and EE. Its cross-sectional area is doubled. Determine the ratio of new deformation to original deformation.

Step-by-Step Solution

0 of 2 Steps Completed
1

10. Load Sharing by Compatible Parallel Bars

A rigid plate is supported by a steel bar and an aluminum bar of equal length. The steel bar has As=400 mm2A_s=400\text{ mm}^2, Es=200 GPaE_s=200\text{ GPa}; the aluminum bar has Aa=600 mm2A_a=600\text{ mm}^2, Ea=70 GPaE_a=70\text{ GPa}. A centered load of 100 kN100\text{ kN} causes the plate to translate without rotation. Determine the force carried by each bar.

Step-by-Step Solution

0 of 2 Steps Completed
1