The formula to calculate the stress ratio (STR) is:
\[ STR = \frac{MINS}{MAXS} \times 100 \]
Where:
Let's say the minimum stress (MINS) is 50 GPa and the maximum stress (MAXS) is 200 GPa. Using the formula:
\[ STR = \frac{50}{200} \times 100 \]
We get:
\[ STR = 25 \% \]
So, the stress ratio is 25%.