Design and Assembly of an Ultrasonic Fatigue Testing Machine

The lifetime approach in fatigue design based on S_N curves establish an infinite life when the cyclic stress applied is below than the endurance limit. Results in this field revealed fatigue failures beyond 10e7 cycles, indicating that there´s no endurance fatigue limit, however obtaining this data with servo-hydraulic testing machine can be very timeconsuming and expensive. Ultrasonic fatigue testing machines are a new generation of devices designed to perform VHCF tests in a very short time. This paper describes the design and assembly of an ultrasonic fatigue testing device working at 20 kHz.