Experimental Validation and Applications of a Phased Array Ultrasonic Testing Probe Model

Abstract: New manufacturing technologies are developed to facilitate flexible product designs and production processes. However, the quality of the final products should not be compromised. The assessment of product quality and integrity lies on various inspection methods. Ultrasonic testing, among other nondestructive testing methods, is widely used as an effective and cost-efficient approach. The phased array technique in the field of ultrasonic testing shows more advantages over conventional technique and is revealing more benefits to industrial applications. To incorporate new technique into practice, it needs to be qualified with experiments. Due to the extensive costs and considerable challenges in experiments, the necessity of researching on reliable numerical models arises and several models had therefore been developed. The mathematical model implemented in the software, simSUNDT , developed at the Scientific Center of NDT (SCeNDT) at Chalmers University of Technology is one of these models for ultrasonic inspection. However, the validity of the models should be proved before supporting or replacing some of the experiments, which should ultimately be accomplished by experiments. In this thesis, the main purpose is thus to further validate the phased array probe model in simSUNDT by comparing simulation with corresponding experiments. An experimental platform is built to fully control the operation conditions and the set of testing results. Well-defined and representative artificial defects in test specimens are manufactured and inspected under some inspection cases in both simulations and experiments. Comparisons in the end show good correlations. Upon validation of the probe model, it is used in several application attempts for possible technique developments. This includes optimization of the generated sound field from a phased array probe and verifying the validity of the used log-normal probability of detection model. The basic ability of generating full matrix capture inspection dataset is also explored. This could provide a simulation scheme for parametric studies to investigate an ultrasonic imaging algorithm, total focusing method, in terms of its defect characterization capabilities.