大型旋转机械稳定运行机理及智能诊断研究
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项目结题报告(全文)
1.热环境下纤维增强复合圆柱壳非线性振动模型
- 关键词:
- 非线性振动;纤维增强复合材料;圆柱壳;材料和几何非线性;热环境
- 李晖;吕海宇;罗忠;孙伟;韩清凯;秦朝烨;闻邦椿
- 《第十八届全国非线性振动暨第十五届全国非线性动力学和运动稳定性学术会议(NVND2021)》
- 0年
- 中国广东广州
- 会议
本文提出了热环境下纤维增强复合圆柱壳的非线性振动分析模型,该模型能够预测不同激励幅值和环境温度下结构的固有频率、阻尼比和振动响应。首先,基于Jones-Nelson材料非线性理论和复模量法,结合多项式拟合技术,给出了考虑振幅和温度依赖性的纤维增强复合材料的非线性杨氏模量、剪切模量和损耗因子的显示表达式。在此基础上,结合Love壳体理论、能量法和von-Karman非线性应变-位移关系,推导了热环境下结构系统的振动微分方程,还详细介绍了非线性杨氏模量、剪切模量和损耗因子拟合系数的确定方法。最后,基于自行搭建的热振实验平台,对CF120碳纤维/环氧复合材料圆柱壳试件开展了测试,验证了所提出的理论模型和分析结果的正确性,并对该类型结构的非线性振动现象进行了实验评估。测试结果表明,随着激励幅值的增大,复合材料壳试件的前3阶固有频率呈现先减后增的趋势,且当环境温度从20℃上升到200℃时,这种变化趋势变得更加显著,固有频率的最大变化程度为8.2%。另外,随着激励幅值和温度的增大,结构的阻尼性能和共振响应都呈现不断增大的趋势。但相对于激励幅值的增大,环境温度的升高对阻尼特性的影响更为显著,结构阻尼的最大变化程度可达到300.5%。
...2.Dynamic gas turbine condition monitoring scheme with multi-part neural network
- 关键词:
- Deterioration;Learning systems;Condition monitoring;Gases;Failure (mechanical);Health management systems;Industrial processs;Integrated networks;Machine learning methods;Performance parameters;Physical mechanism;Sensing performance;Traditional approaches
- Li, Zhouzheng;Feng, Kun;Yan, Binbin
- 《ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, GT 2020》
- 2020年
- September 21, 2020 - September 25, 2020
- Virtual, Online
- 会议
Gas turbines are high value industrial assets with significant roles in various kinds of industrial processes, health management systems are therefore important for helping maintaining gas turbines' stability in long-term operations. With more and more performance data able to be collected by sensors and the new machine learning methods developed, researchers are able to build more powerful digital models to monitor the gas turbine. This paper introduces a performance parameters alarm scheme for gas turbine using an adaptive state following model. The proposed scheme consist of 3 parts: Part 1, a dynamically adaptive multi-part neural network trained using performance data that can simulate different parts of gas turbine and output "normal" sensor data to make comparison with the actual data collected; Part 2, a group of thresholds set according to system noise that flags sudden failures by sensing performance parameter outliers, this also decides which data should be used to update the neural network; Part3, a recorder for "reference point" outputs that can reflect change of the gas turbine's status and detect long-term degradation. Unlike traditional approaches, the proposed adaptive states following model separates long term degradation and short term sudden failure, therefore both faults can be detected more accurately. The core of the proposed method is that physical properties are embedded into the neural network as constraints to regulate training and make the model more interpretable. In our scheme, a gas turbine is divided into 4 parts referencing the equipment's physical mechanism, they are simulated digitally by 4 sub corresponding networks, which are then combined into the proposed integrated network. The proposed scheme achieves an overall pleasing result and shows potential in gas turbine fault analysis. Copyright © 2020 ASME
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