Nonlinear force appropriation in the presence of mode interactions

存在模式相互作用时的非线性力分配

• 批准号: 2846973
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2846973
• 关键词: Nonlinear; force; appropriation; presence; mode

The constant drive to make aeronautic systems more efficient is leading to structures that are increasingly nonlinear. The development and validation of mathematical models predicting the behaviour of such structures requires new experimental testing methods that can extract the adequate nonlinear vibration data. The objective of this project is to develop such methods. We will first derive geometrically nonlinear models (Von Karman kinematics) of conceptually simple academic structures (cantilever and cross beams) before modelling an aero-engine blade with a simplified geometry (free from any intellectual property). With the help of analytical and numerical methods, such as Normal Forms andnumerical continuation, we will study the developed models to determine the appropriate distribution of the excitation that must be used in experimental tests to extract nonlinear vibration modes. The project will then develop new real-time control algorithms, such as adaptive and proportional-integral-derivative (PID), to adjust directly during tests the excitation frequency and the multi-harmonic, multi-point excitation amplitudes required to reach nonlinear resonance. Following the theoretical investigations, the beam and blade structures will be manufactured and the proposed methods validated experimentally. Controllers will be implement using MATLAB/Simulink and deployed on the dSpace real-time controller platform. The structures will be excited using electrodynamic shakers and their response measured using accelerometers. Collected data will be compared with model predictions and help with model validation.

为了使航空系统更有效，不断的驱动导致结构越来越非线性。预测这种结构行为的数学模型的开发和验证需要新的实验测试方法，可以提取足够的非线性振动数据。本项目的目标是发展这种方法。我们将首先推导出概念上简单的学术结构（悬臂梁和横梁）的几何非线性模型（Von Karman运动学），然后用简化的几何形状（不含任何知识产权）对航空发动机叶片进行建模。借助分析和数值方法，如规范形式和数值延拓，我们将研究开发的模型，以确定在实验测试中必须使用的激励的适当分布，以提取非线性振动模式。然后，该项目将开发新的实时控制算法，如自适应和比例积分微分（PID），以在测试期间直接调整激励频率和达到非线性共振所需的多谐波、多点激励振幅。在理论研究之后，将制造梁和叶片结构，并通过实验验证所提出的方法。控制器将使用MATLAB/Simulink实现并部署在dSpace实时控制器平台上。这些结构将使用电动振动器激励，并使用加速度计测量其响应。收集的数据将与模型预测进行比较，并有助于模型验证。