Flutter analysis: Using piecewise quadratic interpolation with mode tracking and wind-tunnel tests

A study on the flutter analysis using piecewise quadratic interpolation (PQI) with mode tracking and wind tunnel tests was conducted. As the first step of the study, the modal analysis of the wing model was made through the conventional finite-element method and the ground vibration test. In the ground vibration test, the plastic foam covering the wing model makes it difficult to measure the dynamic response of the wing model via accelerometers fixed on the foam or excite the wing model through a hammer impacting on the foam. A laser interferometer was used to measure the dynamic responses, subject to a hammer impact, at different locations on the wing model. Two ground vibration tests were performed. The wind-tunnel tests performed by the authors for a flexible wing model verify the efficacy of the revised PQI method. The experimental results show that the proposed method provides accurate predictions of flutter velocity and frequency of the wing model.