Investigation on complex shaped aerospace structure: Reliability and Cost balance

The objective of this work is to identify different types of defects in carbon fiber reinforced polymer (CFRP) specimen provided along ‘Student Challenge’ by using different nondestructive techniques, mostly focused on ultrasonic inspection. Due to complex geometry of the sample the aim of the team is to compare the performance of suitable non-destructive techniques in order to detect, locate, and size the defects. Factors affecting the performance of NDT techniques are sample structure, geometry, dimension, layer thicknesses, material characteristics and their capabilities due to physical phenomena. For each technique, most suitable measurement parameters have been selected: 10 MHz, 32 element transducers for phased array ultrasonic inspection, 15 MHz focused single element transducers for immersion tank inspection, 50 MHz focused transducers with acoustic microscope, and 200 kV voltage along with 600 mA current for X-ray tomography investigations. The results has been compared according to detectability of defects, cost, and time for the inspections. The five different inclusions are identified using different NDT techniques and the size of the defects has been measured. The team reported the quantified performance comparison for the different type of ultrasonic inspections along with the visual inspection and X-ray tomography NDT techniques