Modeling of Ultrasonic Fatigue-Life Testing Machine
D. Dimitrov1 V. Mihailov1 B. Kostov1
1Technical University of Varna, Varna, Bulgaria
Usually fatigue-life tests of materials are long, time-consuming and expensive. With the development of high power piezoceramic actuators nowadays it is possible to provide at very high cycles 10e10 fatigue tests (VHCF) for reasonable times, at high frequency. The ultrasonic fatigue machine consists of piezoceramic transducer, booster, horn and specimen made of tested material. System works in axial resonant regime. The most used working frequency is 20kHz due to some limitation of minimal specimen length. The response of ultrasonic system is modeled, using Structural Mechanic and Piezoelectric interfaces in the following sequence. First eigenfrequencies of the system are determined, second displacement amplitudes and stress distribution in frequency domain. Determined eigenfrequensy is similar to the experimental, if a proper values (experimentally determined) of material constants is used.