The formula to calculate the Safe Stress (σw) is:
\[ \sigma_w = \frac{\sigma_y}{fs} \]
Where:
Safe Stress is based on the yield strength of the material and is defined as the yield strength divided by a factor of safety.
Yield Strength can be defined as follows: a straight line is constructed parallel to the elastic portion of the stress–strain curve at a strain offset of 0.002.
Factor of Safety expresses how much stronger a system is than it needs to be for an intended load.
Let's assume the following values:
Using the formula:
\[ \sigma_w = \frac{35000000}{2.8} \]
Evaluating:
\[ \sigma_w \approx 12500000 \, \text{Pascals} \]
The Safe Stress is approximately 12500000 Pascals.
| Yield Strength (σy) (Pascals) | Factor of Safety (fs) | Safe Stress (σw) (Pascals) |
|---|---|---|
| 30000000 | 2.5 | 12,000,000.0000 |
| 30000000 | 2.8 | 10,714,285.7143 |
| 30000000 | 3 | 10,000,000.0000 |
| 35000000 | 2.5 | 14,000,000.0000 |
| 35000000 | 2.8 | 12,500,000.0000 |
| 35000000 | 3 | 11,666,666.6667 |
| 40000000 | 2.5 | 16,000,000.0000 |
| 40000000 | 2.8 | 14,285,714.2857 |
| 40000000 | 3 | 13,333,333.3333 |