Two bars each of length I and 4 the same material are subjected to th...
For 1st bar,
Stress
Strain energy stored =
2nd bar, AB = F
1Stress energy = AB + BC
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Two bars each of length I and 4 the same material are subjected to th...
Explanation:
Given:
- Two bars of the same material
- Length of each bar = L
- Tensile force applied on both bars = P
- Diameter of the first bar = 2d
- Diameter of the second bar = d for a length of 2d, and 2d for the remaining length
To find:
The ratio of strain energies of the two bars
Strain Energy:
Strain energy is the energy stored in a material when it is deformed under load. It can be calculated using the formula:
Strain Energy (U) = (1/2) * Stress * Strain * Volume
Where:
Stress = Force / Area
Strain = Change in length / Original length
Volume = Cross-sectional area * Length
Calculating Strain Energy for the first bar:
- Diameter of the first bar = 2d
- Radius (r) = (2d)/2 = d
- Cross-sectional area (A) = π * r^2 = π * d^2
- Volume (V) = A * L = π * d^2 * L
Now, let's calculate the strain energy (U1) for the first bar:
- Stress = P / A
- Strain = Change in length / Original length = L / L = 1
Substituting the values into the formula:
U1 = (1/2) * (P / A) * 1 * (π * d^2 * L)
Calculating Strain Energy for the second bar:
The second bar has two different diameters:
- Diameter of the first part = d
- Diameter of the second part = 2d
We need to calculate the strain energy separately for each part and then add them.
For the first part:
- Radius (r1) = d/2
- Cross-sectional area (A1) = π * (d/2)^2 = π * d^2 / 4
- Volume (V1) = A1 * L = (π * d^2 / 4) * L
Now, let's calculate the strain energy (U1) for the first part:
- Stress = P / A1
- Strain = Change in length / Original length = L / L = 1
Substituting the values into the formula:
U1 = (1/2) * (P / A1) * 1 * ((π * d^2 / 4) * L)
For the second part:
- Radius (r2) = 2d/2 = d
- Cross-sectional area (A2) = π * (d)^2 = π * d^2
- Volume (V2) = A2 * L = (π * d^2) * L
Now, let's calculate the strain energy (U2) for the second part:
- Stress = P / A2
- Strain = Change in length / Original length = L / L = 1
Substituting the values into the formula:
U2 = (1/2) * (P / A2) * 1 * ((π * d^2) * L)
Total strain energy for the second bar:
U2 = U1 + U2 = (1/2) *