SS-V: 7000 SN Uniaxial Fatigue
Test No. VF01 Find the Fatigue life when a constant amplitude Stress-Life analysis is performed.
Definition
A stepped shaft with fillet is subjected to axial loading.
The units are SI.
Figure 1.
Dimensions: D = 120 mm, d = 60 mm, r = 3 mm
The material properties are:
- Properties
- Value
- Modulus of Elasticity
- 2.03e11 pa
- Poisson's Ratio
- 0.3
- Ultimate Tensile Stress (UTS)
- 8.63e8 pa
- Fatigue Strength Coefficient (SR1)
- 1.101e9 pa
- First Fatigue Strength Exponent (b1)
- -7.5e-2
- Cycle Limit of Endurance for 1 Segment SN Curve (NC1)
- 1e6 cycles
Loading from structural analysis follows the below variation over time:
| Time [sec] | Amplitude Factor |
|---|---|
| 0 | 0 |
| 1 | 250 |
| 2 | 0 |
| 3 | -250 |
| 4 | 0 |
Figure 2.
No modifying factors (Surface Roughness and Fatigue Strength Reduction factor) are used.
Results
The following image and table show the fatigue life at points A and B.
Figure 3.
Figure 3.
| Coordinates [mm] | Reference [Target Value]* | SimSolid | % Difference | |
|---|---|---|---|---|
| Point A | (-127.586, -2.79319, -1.48875) | 1310 | 1303 | 0.4% |
| Point B | (-85.7703, -16.8757, -1.48566) | 1770 | 1764 | 0.3% |
*The SimSolid results are compared with efatigue calculator.