共查询到20条相似文献,搜索用时 15 毫秒
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为了研究发动机的突加不平衡故障,建立了航空发动机低压转子模型,完成了转子实验器的模态校核。在此基础上对突加不平衡下实验器的转子件响应进行了理论分析与实验对比。进一步建立了转子-支承-机匣分析模型,完成了响应的分析与实验结果对比。结果表明:建立的转子-支承-机匣模型考虑了发动机实际运转过程中的角加速度项和挤压油膜阻尼器瞬态项,分析结果与实验结果相符,突加不平衡位置处振动位移响应的分析结果与实测结果之间的相对误差为2.1%。在校核转子件响应后,将转子件载荷作为支承-机匣模型的载荷输入,考虑发动机结构特征,建立支承-机匣模型进行响应分析,分析结果与实验结果基本一致,对于靠近突加不平衡位置的振动速度响应,其分析结果与实测结果之间的相对误差不超过4.7%。分析结果能够体现突加不平衡后转子响应的冲击特征和转子-支承-机匣响应层层减弱的过程,所建立的计算方法具有较好的推广性。 相似文献
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王伟 《航空精密制造技术》2011,47(2):9-11
通过对轴向车铣薄壁回转体工件有限元模拟结果的分析,得出振幅随刀具转速的变化,验证了有限元方法进行薄壁回转体工件动力学分析的合理性.分析结果表明,车铣加工过程中应合理选择铣刀转速,使切削频率避开共振频率. 相似文献
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仿真结果检验和状态分析方法 总被引:1,自引:1,他引:0
提出了一种仿真结果检验和状态分析方法,不仅可以有效地判断仿真结果正确与否,而且当仿真结果不正确时,可以进一步对仿真结果进行状态分析,确定哪些状态的仿真结果正确,哪些状态的仿真结果错误,从而指导仿真软件系统的编制和修改.此外,还给出了仿真结果检验表和状态分析表,便于工程应用. 相似文献
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《中国航空学报》2021,34(10):220-236
Research on the transition phase of tail-sitter Unmanned Aerial Vehicles (UAVs) is crucial for trajectory planning and performance analysis. This study focuses on the analysis of the transition characteristics and path of a small dual-rotor tail-sitter UAV, including static and dynamic computations. The system input time delay and actuator dynamics are specifically considered during the dynamic analysis, and these actual physical properties ensure that the computation results are reliable and reasonable. The UAV steady-state limit is obtained through static analysis, which is also adopted to verify the correctness of the dynamic results. In regard to the dynamic analysis, several typical transition approaches are computed based on different initial states and optimization objective functions, and the different computations are applicable under specific task conditions. The off-line dynamic results of the transition path and actuator output sequence could also be adopted as reference values for the transition process during real flight. A comparison of the static and dynamic results illustrates the necessity of combining these two methods for UAV transition characteristic analysis. Furthermore, the UAV conceptual parameters related to the transition path are also studied, and the obtained quantitative characteristics provide feedback for the UAV conceptual design. 相似文献
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This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine. Compared with local sensitivity analysis results, global sensitivity analysis could provide more information on parameter interactions, which are significant in complex system safety analysis. First, a deterministic aviation reciprocating engine thermodynamics model is developed and parameters of interest are defined as random variables. Then, samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution. Eventually, results from engine model are generated and importance indices are calculated. Based on the analysis results, design is improved to satisfy the airworthiness requirements. The results reveal that by using global sensitivity analysis, the parameters could be ranked with respect to their importance, including first order indices and total sensitivity indices. By reducing the uncertainty of parameters and adjusting the range of inputs, safety criteria would be satisfied. 相似文献
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V. A. Mikheev S. D. Smol’nikov S. V. Surudin D. V. Savin 《Russian Aeronautics (Iz VUZ)》2016,59(1):145-150
The results of shaping process were obtained by the process scheme of serial stretching for biconvex skin of workpieces using the ANSYS/LS-DYNA software. The analysis is based on different flow material characteristics during plastic deformation at solid friction. A statistical analysis of the calculation results for disturbing factors assessment is carried out. 相似文献
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A fixed frequency LCL-type series resonant converter (SRC) which uses an inductive output filter is proposed. Steady-state analysis of the converter is presented using complex ac circuit analysis. Based on the analysis, a simple design procedure is given. Detailed space integrated control experiment (SPICE) simulation results are presented to evaluate the performance of the designed converter under varying load and supply voltage conditions. Also, detailed experimental results obtained from a metal-oxide-semiconductor field-effect transistor (MOSFET) based 500 W converter are presented to verify the analysis and SPICE simulation results. The results obtained from the analysis, SPICE simulation and the experimental converter are compared. The proposed converter requires a narrow variation in pulsewidth while maintaining lagging power factor mode of operation for a very wide variation in the load as well as supply voltage 相似文献
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针对结构热试验非均匀热环境模拟的精细化需求,以石英灯阵热流分布理论解析方法为基础,建立了基于线性分析模型的石英灯阵功率快速优化方法,对石英灯阵模拟非均匀气动加热的功率优化问题进行了分析研究。结果表明:线性分析方法可以快速有效地优化石英灯阵功率,对于比较平缓的热流分布可以获得较好的优化结果,对于大梯度热流分布也能获得与遗传算法较为一致的热流优化结果和规律;模拟非均匀气动加热的功率优化结果对热流输入比较敏感,需要通过优化来选择合适的测点范围和测点数量得到相对稳定的系数矩阵。相关研究结果对模拟非均匀气动加热的石英灯阵功率优化设计具有重要参考意义。 相似文献
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以确定性疲劳裂纹扩展分析为基础,推出了一种多裂纹扩展分析的新方法———变量优化法.给出了两种典型结构细节多裂纹扩展分析结果,结果表明:变量优化法比工程试凑法更有效,精度更高,比解非线性方程组法更符合工程实际,更容易被人们所接受。 相似文献
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安全性分析是适航符合性验证的重要方法。对马尔可夫分析在系统安全性评估中的应用进行了深入研究,阐明了马尔可夫分析的作用与应用时机,结合功能危险状态“V1速度后起落架无指令收起”分别给出了在初步系统安全性评估与系统安全性评估中进行马尔可夫分析的一般方法,将马尔可夫分析与故障树分析的结论进行了对比,袁明了本文方法的适用性。 相似文献
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We compare the results of analyzing the stress strain state for the tubular skid landing gear with regard for the physically and geometrically nonlinear scheme of deformation; the analysis is carried out by the finite element method and with the aid of a special beam-type design model. The analysis has been performed for a real helicopter design. The peculiarities of deforming the aircraft structures of the type under study are shown based on the comparison results. 相似文献