Analysis Of Mechanical Performance And Optimum Design On Pulsating Vacuum Sterilizer

Pulsating Vacuum Sterilizer, belonging to the category of pressure vessel, has been used widely in medical, pharmaceutical, biological products, laboratory animals and food industries. As a special equipment prone to explosion, it must be monitored by the State Department supervision. Lumen cracks are found in periodic testing by the Institute of special equipment in Beijing. Considering the working pressure, temperature and environmental factors during sterilization process, failure of its destruction is a highly nonlinear process.In this paper, a fairly systematic study about the pulse vacuum sterilizer was made through numerical simulation technology and methods of structural optimization. The main researches are summarized as follows:(1) Using finite element software as the platform, the finite element analysis model is established, and a large number of numerical simulation on cracking cavity, including the focus of analysis and structural parameters, are executed. Combined with experiment testing, the environment is identified as an incentive for corrosion, and fatigue play the role of aggravating damage after cracks in micro-generated.(2) Researches on the cost of container welding structure problem (including the sheet materials forming processing, assembly, welding and painting, etc) are discussed. Container stiffener thickness and the number of stiffeners are taken as design variables; designing constraints is to meet the strength requirements, using response surface method to make it explicit; establishing the most economical structure optimization model. The model contains an optimization model with discrete-continuum mixed variables which are more difficult to solve. Hierarchical optimization strategy is adopted in this paper. Internal circulation is high order contraction for dealing with continuous variables function, sequential quadratic programming to solve optimization model, and the outer circulation applies the Fibonacci sequence to deal with the number of stiffener optimization, whose program is stable and of high efficiency for solving.(3) Response surface modeling method, based on the structure of the sample points the finite element analysis, is the explicit model of function. Considering that the sample points of the explicit fitting function is independent of each other, this paper, based on Windows platform, built the master-slave parallel environment, prepared the parallel algorithms, and achieved parallel structure optimization. (4) In the specialized area of software design, MSC.Nastran, Fortran and Visual C++ are used together in order to realize a fully automated optimization process and to improve the optimization efficiency. It also prepared friendly user form, to facilitate the input of the the parameters of structure and enhance the application of the software efficiency and utility.