Ultrasonic methods are widely applied for nondestructive evaluation of structural components during both the manufacturing process and subsequent field inspections. The field inspections often require expensive teardown in order to access the back surfaces of critical components. Active ultrasonic methods are also a subject of ongoing research for structural health monitoring whereby transducer...

The in-situ testing of early age concrete strength is crucial for determining the time of form removal from concrete elements, opening highways to traffic or applying of prestress to steel reinforcement. A nondestructive ultrasonic technique, which measures the reflection loss of ultrasonic transverse waves at a concrete-steel interface, is presented in this paper. The focus is to compare wave ...

The effects of microstructures during creep on the ultrasonic attenuation have been investigated for Ni based superalloy (IN738LC). The cuboidal γ′ precipitates in the virgin material became coarsened preferentially in the direction perpendicular to the applied stress axis as creep time increased. The length of γ′ precipitates increased with creep time, while the width increased slightly. The i...

In this research, the performance of ultrasonic pulse velocity (UPV) in concrete is examined as a nondestructive experiment in order to estimate mechanical (compressive and tensile strength) and durability (water absorption) properties of fiber-reinforced self-compacted concrete For this purpose 11 mixture designs containing 3 types of fibers (steel: 0.1, 0.2, 0.3 and 0.4 percent by volume, Pol...

Fire damage to concrete causes contact-type defects that degrade its durability through impaired mechanical properties. Various nondestructive tests are used to evaluate defects induced by fire damage. Recently, nonlinear ultrasonic methods such as the nonlinear resonance vibration method and nonlinear modulation method have been introduced. These nonlinear methods are more sensitive to fire-in...

This paper describes a threefold method of testing the performance of an array-based ultrasonic tool for nondestructive testing of spot welds. The tool is described in its capabilities, use, and advantages over existing counterparts. Performance testing for and the results from carrying out the testing are described. The three performance testing methods include 1) the use of calibrated samples...