SN Curve Calculator

Formula

The formula to calculate the SN Curve (N) is:

\[ N = K \cdot S^m \]

Where:

\(N\) is the SN Curve (number of cycles to failure)
\(S\) is the stress range
\(K\) is the material constant
\(m\) is the material constant

What is the SN Curve?

The SN Curve represents the relationship between the cyclic stress amplitude and the number of cycles to failure for a material. It is used in fatigue analysis to predict the lifespan of materials under cyclic loading. The curve is typically plotted on a logarithmic scale, with the stress range on the x-axis and the number of cycles to failure on the y-axis.

Example Calculation

Let's assume the following values:

Stress Range (S) = 100 MPa
Material Constant (K) = 1e12
Material Constant (m) = -3

Using the formula to calculate the SN Curve:

\[ N = 1e12 \cdot 100^{-3} = 1e12 \cdot 1e-6 = 1e6 \text{ cycles} \]

The SN Curve value is 1,000,000 cycles.