Non-linear aeroelasticity and health monitoring of anisotropic curved structures

拟议的工作涉及基础研究和应用研究。它是上述研究的延续，通过整合结构和流动的更现实和复杂的方面，其中将考虑结构的非线性方面以及流体非线性和非比例阻尼。研究进展。近年来，我们的团队研究了两个主要领域：流体结构系统的数值分析和振动信号处理方法。这些研究导致了许多科学文章的出版，我们的结果被IREQ，Spar Aerospace/EMS Technologies，CAE Electronics，NRC航空航天研究所的结构，材料和推进组，庞巴迪和P&WC等公司使用。这些研究产生了以下结果：圆柱壳和圆锥壳振动的数值模拟受到可压缩或不可压缩流体流。由于这些壳单元在航空航天结构中的广泛应用，预测壳体在流动作用下的动力失稳是航空工程师面临的一个具有挑战性的课题。对于这样一个包含复杂结构、边界条件、材料和载荷的问题，当影响颤振边界的因素发生变化时，分析模型变得非常复杂。因此，基于混合有限元法的数值软件包已被开发来描述曲壳的气动弹性行为。与现有的商业有限元软件相比，它提供了非常快速和精确的收敛，计算时间和成本更少。这些工作的结果已在国际会议上发表，并发表在国际期刊上[1，2]。开发的线性理论足以预测颤振的发生，然而，非线性壳体理论需要捕获的实际极限环振幅的颤振是留给这个拟议的研究。

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.