囊式空气弹簧(convoluted air spring,CAS)的结构参数是影响其力学特性的重要因素,解决结构参数的辨识难题是计算囊式空气弹簧承载、刚度特性的关键途径。采用几何与力学分析方法,以单曲曲囊弧长和盖板有效法兰半径为关键设计参量,建立...囊式空气弹簧(convoluted air spring,CAS)的结构参数是影响其力学特性的重要因素,解决结构参数的辨识难题是计算囊式空气弹簧承载、刚度特性的关键途径。采用几何与力学分析方法,以单曲曲囊弧长和盖板有效法兰半径为关键设计参量,建立了基于关键设计参量的囊式空气弹簧统一结构参数预测模型。搭建了结构参数测试装置,试验验证了统一结构参数模型的正确性。揭示了CAS有效容积及其变化率、有效面积与关键设计参量均正相关,但有效面积变化率与曲囊弧长正相关、与有效法兰半径呈负线性相关特性,为设计刚度更低的CAS提供指导;进一步指出有效法兰半径对CAS结构参数的影响比曲囊弧长更为显著,增大有效法兰半径能够明显增大有效面积而显著提升CAS的承载特性,为保证工作气压不变前提下提升CAS承载能力提供了设计指引。研究结果为设计阶段准确计算囊式空气弹簧的结构参数、力学特性奠定基础,也为其结构参数设计与优化提供理论支撑。展开更多
The current work is concerned with modelling and analysis for a pilot relief valve, thus successfully bringing a systematic method for designing and analyzing similar valves. The essence of the work is to solve two im...The current work is concerned with modelling and analysis for a pilot relief valve, thus successfully bringing a systematic method for designing and analyzing similar valves. The essence of the work is to solve two important problems, one for positions of the pilot valve influenced by flow force and the other is for the opening of the relief valve governed by a thin annular plate. The computational fluid dynamics(CFD) method is used to present the flow force. Using a series of experiments, the flow rate versus pressure drop shows the rationality of the CFD results. In order to obtain the opening of relief valve with higher accuracy, the large deflection theory of thin plates is adopted. An equivalent method for replacing the concentrated force is innovatively proposed so that all of the loads of the plates can be given by a unified expression, which reduces the number of the governing equations and intermediate boundary conditions. For presenting a very simple and reliable method for solving the governing equation, an unconstrained nonlinear optimization is innovatively introduced to solve the deflection of the thin annular plate. Being verified by finite-element method(FEM) of the relief valve, the equivalent method and optimization can solve deflection of thin plates rapidly and accurately. Reflected through a complete model for the pilot relief valve, the theoretical flow rate of the pilot relief valve is consistent with experimental conclusion. Once again, the comparisons bring us insight into the accuracy of the method adopted in the current work.展开更多
文摘囊式空气弹簧(convoluted air spring,CAS)的结构参数是影响其力学特性的重要因素,解决结构参数的辨识难题是计算囊式空气弹簧承载、刚度特性的关键途径。采用几何与力学分析方法,以单曲曲囊弧长和盖板有效法兰半径为关键设计参量,建立了基于关键设计参量的囊式空气弹簧统一结构参数预测模型。搭建了结构参数测试装置,试验验证了统一结构参数模型的正确性。揭示了CAS有效容积及其变化率、有效面积与关键设计参量均正相关,但有效面积变化率与曲囊弧长正相关、与有效法兰半径呈负线性相关特性,为设计刚度更低的CAS提供指导;进一步指出有效法兰半径对CAS结构参数的影响比曲囊弧长更为显著,增大有效法兰半径能够明显增大有效面积而显著提升CAS的承载特性,为保证工作气压不变前提下提升CAS承载能力提供了设计指引。研究结果为设计阶段准确计算囊式空气弹簧的结构参数、力学特性奠定基础,也为其结构参数设计与优化提供理论支撑。
文摘The current work is concerned with modelling and analysis for a pilot relief valve, thus successfully bringing a systematic method for designing and analyzing similar valves. The essence of the work is to solve two important problems, one for positions of the pilot valve influenced by flow force and the other is for the opening of the relief valve governed by a thin annular plate. The computational fluid dynamics(CFD) method is used to present the flow force. Using a series of experiments, the flow rate versus pressure drop shows the rationality of the CFD results. In order to obtain the opening of relief valve with higher accuracy, the large deflection theory of thin plates is adopted. An equivalent method for replacing the concentrated force is innovatively proposed so that all of the loads of the plates can be given by a unified expression, which reduces the number of the governing equations and intermediate boundary conditions. For presenting a very simple and reliable method for solving the governing equation, an unconstrained nonlinear optimization is innovatively introduced to solve the deflection of the thin annular plate. Being verified by finite-element method(FEM) of the relief valve, the equivalent method and optimization can solve deflection of thin plates rapidly and accurately. Reflected through a complete model for the pilot relief valve, the theoretical flow rate of the pilot relief valve is consistent with experimental conclusion. Once again, the comparisons bring us insight into the accuracy of the method adopted in the current work.
