Flexibility Analysis And Experiment Research Of The Hydrogen Main Value Bellows Compenents

The stability and reliability of the entire system is affected directly by the flexibility of hydrogen main valve bellows assembly in a good or bad condition, which plays an important role in a rocket engine. Bellows parametric modeling and finite element simulation are important parts of the bellows flexibility analysis. Collection and analysis of the flexibility data is one of the important module, which directly affects the determination of the bellows assembly flexibility.Currently, the hydrogen main valve bellows assembly is mainly relied on the detection of flexibility inspected by human hands and eyes. The detection efficiency is definitely low and there is a large human error. Meanwhile, there is no data about the motion characteristics of the bellows to support qualitative analysis of its flexibility good or not. Owing to the important operating characteristics and structural shape of metal bellows, strength, stiffness, stability and fatigue life affect the flexibility of its movement. The metal bellows are formed complexly. When the structural parameters change, the phase of the project for design and validation experiment occupy higher research and development costs. In such a condition, longer development cycle, the urgent need to solve is to develop a set of metal bellows parametric modeling and simulation software platform.Firstly, the research is focused on the working process of the hydrogen main valve bellows assembly. For structural properties of the metal bellows and reliability issues, a simplified model of the bellows forming process is established using the ANSYS, a kind of finite element simulation software. The study includes the axial stiffness, deformation mechanism and fatigue life for large bellows and small ripple of the hydrogen main valve, providing a theoretical basis for the engineering design and bellows assembly flexibility assessment standards. A complete set of bellows analysis PC system is consist of the user login module, data acquisition module, flexibility analysis module and bellows parametric modeling and simulation modules. Visual C ++ is applied on ANSYS for secondary development to achieve the bellows parametric modeling and simulation software. The platform is set up with the function module of the parametric modeling, static analysis, modal analysis, transient dynamics analysis and post-processing modules. The presence of the parametric modeling platform is convenient to summarizing the stress distribution for various bellow parameters of axial, radial and wall thickness in specified load, which provides data support for engineering design. Users can manage the user information and product information via login module. The data acquisition module is designed for parameter setting and lower computer data collection. The flexibility analysis module provides the deviation image, histograms of the deviation distribution, velocity analysis, determined limit range and many other flexible detection methods. Meanwhile, the presence of ACCESS database data provides a variety of ways to achieve the data interaction between the PC system and the database.Lastly, an air pressure-motor revolution characteristic equation of the detection system is obtained through experiments. A pneumatic linearization scheme is put forward, and a kind of semi sine wave signal shows the algorithm is of good traceability. The pneumatic linear scheme meets the system requirements. Owing to the established evaluation criteria of bellows assembly flexibility, assessment results are obtained for different products of bellows assembly flexibility.