Damage Detection Methodology Using Ultrasonic Non-destructive Testing for Composites Structures

Damage detection methodology utilizing A-scan and C-scan concept for detecting flaws for composite structure has been presented Ultrasonic bulk wave has been used for non-destructive testing of the composite specimen. Carbon fiber composites have been tested for different types of damages using longitudinal waves. Two sample specimens consisting of a de-lamination, a through hole, and resin rich region have been made using vacuum assisted resin transfers molding (VARTM) process. Signals from various regions of sample specimen have been acquired and processed for studying the features/patterns for various types of damages. A-scan based code for visualizing damage has been developed to qualitatively identify damage in the structure. Various features such as peak amplitude, energy, and time of flight in the selected time window of A-scan signal have been used to assess damage. Reference signal from healthy region can be selected by the user for quantitative analysis. Damage detection methodology is to manually A-scan the structure with the developed software so as to ascertain damage location qualitatively and then perform complete Cscan around selected region. Inspection is carried out using contact testing. By using developed A-scan software it is possible to identify damaged region in the least possible time.