Finite Element Analysis And Reliability Design Of Package Dyeing Machine Vat

Package dyeing machine is a kind of yarn dyeing machine, which dyes spindles by the circulation pump to control the circulation flow of the dye in the dye vat. The main structures of package dyeing machine are vat, creel, circulation pump, heat exchanger and control system, and the vat is a kind of tooth-lock quick opening pressure vessel which is composed of cylinder head and cylinder body. As the main bearing structure of package dyeing machine, the safety and reliability of vat are affected by many factors, including structural design, manufacturing, technology, material properties, management and environment. The quick opening structure and head are important bearing contactors of vat, which play a determinant role for reliability of vat. This paper took GF241XL-21type package dyeing machine as the research object and used the method combining the theoretical analysis and finite element simulation to study the force and contact condition of the meshing part of quick opening structure. Meanwhile, parametric modeling, optimization design and failure probability analysis were carried out for dished head to improve the safety and reliability of package dyeing machine. The main research contents are as following:Firstly, chapter1briefly stated the background and significance of the study, introduced the classification, application and design of pressure vessel, analyzed the main failure of pressure vessel, summarized the research status of pressure vessel design methods at home and abroad, and presented the basic theory of pressure vessel design.Secondly, chapter2introduced the vat material requirements and calculating cases, and determined the vat material and related parameters for calculating. The contact mechanical model for the quick opening structure of vat was established, and the stress distribution of the quick opening structure was analyzed based on this model. According to the related standards of pressure vessel design and calculation, the results of theoretical calculation were judged to meet the design requirement.Thirdly, chapter3introduced the finite element software ANSYS contact analysis steps and methods, established the finite element contact model of quick opening structure meshing part, and carried out simulation analysis for this model. The dangerous sections of quick opening structure was obtained, and the stress on the dangerous sections was equivalent linearized. The equivalent stress was checked based on stress classification method of pressure vessel stress. Meanwhile, the contact strength and slip state were studied to provide a reference for the design of tooth-lock quick opening structure.Fourthly, chapter4designed the structure size for dished head which was an important bearing contactor of vat, used the optimization module of finite element analysis software ANSYS Workbench to parametric model and finite element analyze for dished head. The key parameters affecting the equivalent stress and total deformation were obtained through sensitivity analysis. The structure size of dished head was optimized by using the design of experiments method and goal-driven optimization method. The reliability calculation model was established by considering the correlation between stress and deformation. Using six sigma design criteria and latin hypercube sampling method, the probability distribution of maximum stress and total deformation were obtained. The result of the reliability calculation before and after optimization showed that the reliability was improved obviously after optimization.Finally, chapter5summarized the research contents and pointed out the future research content of package dyeing machine vat.