I. Single-Point Fatigue Test Method
Application: Suitable for metallic components subjected to rotating bending loads at room temperature, elevated temperatures, or in corrosive environments.
Features:
- Approximates fatigue curves and estimates fatigue limits when sample quantities are limited.
- Typically employs bending fatigue testers or tension-compression fatigue testers.
II. Staircase Fatigue Test Method
Application: A precise and widely used technique to determine the fatigue limit of metallic materials or structures. It is particularly useful when direct measurement of fatigue strength for a specified lifespan is impractical.
Features:
- Indirectly measures fatigue strength by systematically varying stress levels between successive samples.
- Primarily used to characterize random fatigue behavior in medium-to-long lifespan regimes.
- Requires tension-compression fatigue testers.
III. High-Frequency Vibration Fatigue Test Method
Application: Addresses the limitations of conventional fatigue tests (typically <200 Hz) by simulating high-frequency loading conditions (e.g., ≥1,000 Hz) to study fatigue damage in components operating under resonant or cyclic inertial loads.
Features:
- Utilizes electrodynamic shakers to generate high-frequency cyclic inertial forces.
- Ideal for evaluating fatigue performance in military, aerospace, and automotive applications under high-cycle, low-amplitude conditions.
- Equipment includes controllers, charge adaptors, power amplifiers, accelerometers, and vibration shakers.
Conclusion:
Each method serves distinct purposes: single-point tests provide quick approximations, staircase methods refine fatigue limit estimates, and high-frequency vibration tests address extreme operational conditions. The choice of method depends on material properties, loading requirements, and industry-specific needs.
