Residual stress or applied stress measurements using the ultrasonic technique is based on the difference between the propagation velocity of ultrasonic waves in the stressed and relaxed state of the material tested.
The ultrasonic waves are emitted from a piezoelectric transducer into the steel. They are propagated in a specific area of the steel and are detected by one or two receivers. The mean stress is measured in the area where the waves are propagated.
The results of this non-destructive stress measurement method can be used for improving of the accuracy of FEA-Models as well as for better understanding of the exact locations of high stresses and/or areas to be treated by Ultrasonic Peening.
The Ultrasonic measurment method can be used to measure:
- external/applied stresses in order to correlate these against FEA models;
- residual stresses previous and subsequent to Ultrasonic Peening treatment;
- residual stresses due to heat treatment;
- residual stresses due to manufacturing process.
