ASME Elliptic Shaft Diameter Calculator
Diameter (d): -
Stress Concentration Factors (Kf for bending):
- Shoulder fillet:
- Small fillet radius: Kf=1.5−2.5
- Large fillet radius: Kf=1.1−1.5
- Keyways:
- Square-ended: Kf=2.5−3.0
- Round-ended: Kf=1.6−2.0
- Holes in shafts:
- Circular hole: Kf=2.0−3.5
- Grooves:
- U-shaped groove: Kf=2.0−3.0
- V-shaped groove: Kf=3.0−5.0
Stress Concentration Factors (Kfs for torsion):
- Shoulder fillet:
- Small fillet radius: Kfs=1.5−2.2
- Large fillet radius: Kfs=1.2−1.5
- Keyways:
- Square-ended: Kfs=2.0−2.5
- Round-ended: Kfs=1.5−1.8
- Holes in shafts:
- Circular hole: Kfs=2.0−3.0
- Grooves:
- U-shaped groove: Kfs=1.8−2.5
- V-shaped groove: Kfs=2.5−4.0
Distorsion-Energy (Von Mises)
![\[ \sigma_{vm} = \sqrt{\left(\frac{32M_a}{\pi d^3}\right)^2 + 3\left(\frac{16T_a}{\pi d^3}\right)^2} \]](http://pttensor.com/wp-content/ql-cache/quicklatex.com-fc00e3302a7b7688c0142a468131af02_l3.png "Rendered by QuickLaTeX.com")
Goodman
![\[ \frac{\sigma_{\text{alt}}}{S_e} + \frac{\sigma_{\text{mean}}}{S_u} \leq \frac{1}{n} \]](http://pttensor.com/wp-content/ql-cache/quicklatex.com-11c30fbfcadefc531e9ada111746bfec_l3.png "Rendered by QuickLaTeX.com")
Gerber
![\[ \frac{\sigma_{\text{alt}}}{S_e} + \left(\frac{\sigma_{\text{mean}}}{S_u}\right)^2 \leq \frac{1}{n} \]](http://pttensor.com/wp-content/ql-cache/quicklatex.com-ec9618bfbed4613132e9a005581b4680_l3.png "Rendered by QuickLaTeX.com")
ASME Elliptic
![\[ (\frac{\sigma_{\text{alt}}}{S_e})^2 + (\frac{\sigma_{\text{mean}}}{S_y})^2 \leq \frac{1}{n^2} \]](http://pttensor.com/wp-content/ql-cache/quicklatex.com-477914bbefed8ae47bea879e37d208fd_l3.png "Rendered by QuickLaTeX.com")
Soderberg
![\[ \frac{\sigma_{\text{alt}}}{S_e} + \frac{\sigma_{\text{mean}}}{S_y} \leq \frac{1}{n} \]](http://pttensor.com/wp-content/ql-cache/quicklatex.com-61df39fe8c7153890baf407b2cbf4a0f_l3.png "Rendered by QuickLaTeX.com")
The choice of failure criterion for calculating shaft diameter depends on the application, material behavior, and required safety margins:
- Goodman:
- Use When: High-cycle fatigue scenarios with significant alternating stresses and minimal mean stresses.
- Why: Linear, suitable for ductile materials with moderate accuracy. Common in general machine design.
- Gerber:
- Use When: High-cycle fatigue with significant alternating and mean stresses, particularly for ductile materials.
- Why: Nonlinear curve fits material behavior well, especially for components subject to combined stresses.
- ASME Elliptic:
- Use When: Moderate-cycle fatigue with combined bending and torsion stresses, and when yield strength matters.
- Why: Accounts for mean and alternating stresses, providing a balance between conservative and realistic design.
-
Soderberg:
- Use When: High-safety applications where conservative design is critical, especially for brittle or yield-dominant materials.
- Why: Very conservative, ensuring no failure even under lower stress conditions.
Related Module(s):
TensorConnect project 2024 by pttensor.com Author: Caesar Wiratama