Calculating Strain Energy of Circular Clamped Plate

In summary, calculating the strain energy of a circular clamped plate requires knowledge of material properties and plate dimensions. The formula for calculating it is U = (1/2) * (E * h^2 * (1 - v^2)) * (pi * r^4). The significance of this calculation is to understand the elastic energy stored in the plate under external forces. It cannot be negative, and factors such as material properties, dimensions, and external forces can affect it. It can also be calculated for non-uniform loading by breaking the plate into smaller sections.
  • #1
harpreet singh
40
0
I need to calculate the strain energy of a symmetrical circular clamped plate using the equillibrium equation in polar coordinates.. Can somebody help me with the method??
 
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  • #2
harpreet singh said:
I need to calculate the strain energy of a symmetrical circular clamped plate using the equillibrium equation in polar coordinates.. Can somebody help me with the method??

Ack..lol. I would recommend getting a copy of "Theory of Plates and Shells" by Timoshenko. Any egr. library should have it.
 
  • #3


Sure, I can help you with the method for calculating the strain energy of a symmetrical circular clamped plate using the equilibrium equation in polar coordinates.

First, let's define some variables for clarity. Let R be the radius of the circular plate, t be the thickness of the plate, and E be the Young's modulus of the material.

To calculate the strain energy of the plate, we will use the strain energy density equation, which is given by:

u = 1/2 * σ * ε

Where u is the strain energy density, σ is the stress, and ε is the strain.

In polar coordinates, the equilibrium equation for a circular clamped plate is given by:

∂^2u/∂r^2 + 1/r * ∂u/∂r + 1/r^2 * ∂^2u/∂θ^2 = 0

We can rewrite this equation in terms of stress and strain using the following relationships:

σ_r = E * ε_r

σ_θ = E * ε_θ

Where σ_r and σ_θ are the radial and tangential stresses, and ε_r and ε_θ are the radial and tangential strains, respectively.

Using these relationships, we can rewrite the equilibrium equation as:

∂^2u/∂r^2 + (1/r) * E * (ε_r + ε_θ) + (1/r^2) * E * (ε_r + ε_θ) = 0

Since the plate is clamped, we know that the radial and tangential displacements must be zero at the edges. Therefore, we can simplify the equation to:

∂^2u/∂r^2 + (2/r) * E * ε_r = 0

Integrating this equation twice with respect to r, we get:

u = (1/4) * E * ε_r * r^2 + c1 * r + c2

Applying the boundary conditions of zero displacement at the edges, we get:

c1 = 0 and c2 = 0

Therefore, the strain energy density equation becomes:

u = (1/4) * E * ε_r * r^2

To calculate the total strain energy of the plate, we need to integrate this equation over the entire plate area. Since the plate is symmetrical, we can integrate from r = 0 to
 

1. How do I calculate the strain energy of a circular clamped plate?

To calculate the strain energy of a circular clamped plate, you will need to know the material properties (such as Young's modulus and Poisson's ratio) and the dimensions of the plate. You can use the following formula:
U = (1/2) * (E * h^2 * (1 - v^2)) * (pi * r^4)
Where U is the strain energy, E is the Young's modulus, h is the thickness of the plate, v is the Poisson's ratio, and r is the radius of the plate.

2. What is the significance of calculating strain energy in a circular clamped plate?

Calculating the strain energy of a circular clamped plate allows us to understand the amount of elastic energy stored in the plate when it is subjected to an external force. This information can be useful in designing structures and predicting their behavior under different loads.

3. Can the strain energy of a circular clamped plate be negative?

No, the strain energy of a circular clamped plate cannot be negative. This is because strain energy is a measure of the elastic energy stored in a material, and it is always positive. A negative value would indicate that energy has been released or dissipated, which is not possible in a clamped plate.

4. What are some factors that can affect the strain energy of a circular clamped plate?

The strain energy of a circular clamped plate can be affected by factors such as the material properties, dimensions of the plate, and the magnitude and direction of the external force applied. Additionally, any imperfections or defects in the plate can also impact the strain energy.

5. Can the strain energy of a circular clamped plate be calculated for non-uniform loading?

Yes, the formula for calculating the strain energy of a circular clamped plate can be modified to account for non-uniform loading. This would involve breaking the plate into smaller sections and calculating the strain energy for each section separately. The total strain energy can then be determined by summing up the individual energies.

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