Ultrasonic Technique for Assessment of the Rim Tightness of Hydro Generator Rotor

At the hydroelectric unit No. 11 of the Nizhnekamsk hydroelectric power plant, the filling wedges of a rotor were investigated by ultrasound in the free st     

Fatigue life prediction of structural steel using acoustic birefringence and characteristics of persistent slip bands

Nondestructive evaluation methods provide additional information about the material fatigue behavior and enhance the comprehension of damage evolution thanks to relationship between microstructure and physical properties. This paper deals with optical and ultrasonic investigations of structural steel specimens tested for low-cycle fatigue. The development of persistent slip bands observed on the surface with an optical microscope was quantified using a previously trained neural network and fractal analysis. A surface damage parameter was defined as the ratio of total area of detected slip bands to the area of observed surface. Relationships between the rate of change and critical value of the damage parameter, the strain range, and the fatigue life were established. A single square relationship between relative number of cycles and ratio of the surface damage parameter to its critical value was obtained. Acoustic birefringence was measured by the echo method. The effect of the strain range on the rate of change in acoustic birefringence was investigated. A single linear relationship between relative number of cycles and change in acoustic birefringence was established. An algorithm for predicting the material remaining life, combining optical and ultrasonic data, was proposed.     

Use of Texture-Dependent Ultrasonic Parameter as Indicator of Degradation of Hot-Rolled Thin-Sheet Steel Under Uniaxial Tension

Journal of Nondestructive Evaluation - Centrifugal pumps (CPs) are mainly composed of impeller and bearings. The operation of the CPs is disturbed if any of its components is faulty. Bearings...     

Monitoring the State of Stainless Steel under Cyclic Deformation by the Acoustic and Eddy Current Methods

Measurement Techniques - The effect of the amplitude of deformation on the intensity of the change of the elastic and magnetic properties of austenitic stainless steel 12Kh18N10T was studied. It is...