针对高转速、高温升、大载荷等持续复杂的工况波动引起的航空发动机高速轴承故障诊断问题,提出了一种新型的深度图迁移学习算法,以及波动工况下基于图迁移卷积网络(graph transfer convolutional networks,简称GTCNs)的航空发动机高速...针对高转速、高温升、大载荷等持续复杂的工况波动引起的航空发动机高速轴承故障诊断问题,提出了一种新型的深度图迁移学习算法,以及波动工况下基于图迁移卷积网络(graph transfer convolutional networks,简称GTCNs)的航空发动机高速轴承故障智能诊断方法。首先,利用阶比分析对波动工况下航空发动机高速轴承振动信号进行重采样,将其转化为阶次谱信号作为目标域与源域数据集;其次,采用训练好的一维图卷积网络(onedimensional graph convolutional networks,简称1dGCNs)作为特征提取器,对其高层敏感特征计算其动态多核-最大均值散度(dynamic multiple kernel-maximum mean discrepancy,简称DMKMMD)距离,同时匹配高层与低层特征的边缘分布差异;然后,将对齐后的特征输入到分类器softmax中进行智能故障诊断;最后,在航空发动机高速轴承故障数据上验证了所提方法的有效性与先进性。结果表明,该方法具有更高的诊断准确率与鲁棒性,可以消除大波动工况下健康状态样本分布的差异性,提高诊断可迁移性。展开更多
A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.T...A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.展开更多
基金supported by the National Science and Technology Major Project,China(No.2017-II-0006-0019)the National Natural Science Foundation of China(No.52375266)the Shaanxi Science Foundation for Distinguished Young Scholars,China(No.2022JC-36)。
文摘A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.
