Holistic Approach for Structural Integrity Evaluation of Composite Main Rotor Blades

This work presents modern approach for damage detection in the composite main rotor blades MRB of helicopters. All inspections were made with the use automated systems based on Personal Computer – acquisition and database collection. Non Destructive Testing Methods used for the purpose of that work were the following: • qualitative: shearography, DAIS; • quantitative: Mechanical Impedance Analysis, Pitch – Catch, Ultrasonic. In the article results inspection of specimens with artificial defects made from composite specimens: carbon and glass fiber with sandwich and multilayer and honeycomb structure are presented. Results describe detectability and Possibility of Detection (PoD) for flaws of different size, shape and different kind. Moreover estimation of size was delivered with the use of measurement tools included in the software of automated systems. For comparison of accuracy and reliability of those system software used Kernel of Mathematica Library was created. This software is based on criteria defined for the user and makes possible automatic calculating size of the defect. That software enables much faster and much accurate size estimation of defects. Moreover for the future purposes possibility of automated procedures for flaw estimation could be developed. On the basis of that measurements (and results describing PoD of selected techniques) further tests were applied on the samples of composite main rotor blade of W-3 helicopter. The specimens were prepared with some defects and inspection was performed with the use of selected techniques. Moreover behavior of composite blade structure under low energy impact test of mechanical object was determined. That work proved necessity of the use Non Destructive Testing methods for the quality control and maintenance procedures of composite main rotor blades.