Non-linear aeroelasticity and health monitoring of anisotropic curved structures

点击翻译按钮获取中文摘要

The proposed work involves both fundamental and applied research. It is a continuation of the aforementioned research study by integrating more realistic and complex aspects of structure and flow, in which nonlinear aspects of structure as well as fluid nonlinearity and non-proportional damping will be considered. PROGRESS OF RESEARCH. In recent years, our team has studied two major areas: numerical analysis of fluid structure systems and signal processing methods for vibration. These studies led to the publication of numerous scientific articles and our results were used by companies such as IREQ, Spar Aerospace/EMS Technologies, CAE Electronics the NRC aerospace research institute's structure, materials and propulsion group, Bombardier and P&WC. These studies produced the following results: Numerical simulation of vibration of cylindrical and conical shells subjected to compressible or incompressible fluid flow. Since these shell elements are used widely in aerospace structures, predicting the dynamic instability of shells subjected to flow is a challenging subject that aeronautical engineers are confronted with. For such a problem that contains complex structures, boundary conditions, materials and loading, an analytical model becomes very complicated when undergoing a change of factors affecting the flutter boundaries. Therefore, a numerical package based on a hybrid finite element method has been developed to describe the aeroelastic behavior of curved shells. It provides very fast and precise convergence compared to existing commercial FEM software at less computational time and cost. The results of these works have been presented at an international conference and published in international journals [1, 2]. The linear theory developed is adequate to predict the onset of flutter, however nonlinear shell theory required to capture the actual limit cycle amplitude of the flutter is left for this proposed research.  ***OBJECTIVES. The main goal of this research is to provide new insights on the subject of flutter of curved structures such as cylindrical and conical shells. Particular attention is paid to the influence of parameters such as dynamic pressure, flow angles and panel curvature on aeroelastic behavior. Consistent nonlinear hybrid finite element formulations and efficient solution procedures are developed and presented. The short-term objectives will address the following points: A) Bifurcation and nonlinear dynamic analysis of curved structures. B) Nonlinear aeroelastic analysis of shells of revolution subjected to supersonic flow. C) Sloshing effect on the aeroelastic stability of curved structures. D) Development of a nonlinear method to predict the response of anisotropic curved structures subjected to a turbulent boundary-layer-induced random pressure field.**