Ultrasonic bending fatigue testing method for thin sheet materials

To ensure long life reliability of the machine parts made of thin sheet metals, ultrasonic plain bending fatigue test method for thin sheet metals was developed. One end of the sheet specimen is fixed at a loop point of the bar oscillating at a frequency of 20kHz and the other end is set free. As a result, resonance occurs in the specimen due to vibration at the fixed end and long life fatigue strengths (e. g., fatigue strength at (10)^9 cycles) can be obtained in a short time. This method can be applied to the sheet specimens up to 1.0 mm thick.