Systematic Fatigue Test Spectrum Editing Using Wavelet Transformations

Global Technology Connection, Inc., in collaboration with its academic and industrial partners, proposes to develop a software tool that will incorporate systematic wavelet-analysis-based approach for addressing fatigue in a rotary H-60 helicopter (and aerospace applications in general). This fatigue spectrum editing tool will preserve fatigue damage and minimize testing times and costs as well as account for load interaction effects and minimize clipping. The approach will utilize wavelet analysis which offers a very promising avenue for achieving accelerated fatigue testing using maximum fatigue signal compression. We will leverage advances in using wavelet analysis in automotive and wind turbine fatigue testing. Significant opportunities exist for extending these ideas to aerospace fatigue testing, particularly in multiaxial loading configurations. A systematic wavelet-analysis-based approach is possible for aerospace fatigue spectrum editing that preserves fatigue damage, minimizes testing times and costs, accounts for load interaction effects, and minimizes clipping. In Phase II, we will develop and demonstrate a prototype spectrum editing tool that will use reduced length spectra for many available aerospace fatigue profiles as well as multiaxial, non-proportional loading conditions that are validated in laboratory tests on aluminum samples and test articles. These tests will verify damage equivalency with edited and full spectra loading