Finite Element Analysis And Strength Design For Pressure Vessel With Large Openings

Due to the requirements of technology and structure, pressure vessels often need to have various large openings which go beyond the application of Design by Rules. What can be done is to try to design by making comparative analysis through experiments and experience, so that its safety and reliability can not be guaranteed. However, stress analysis based on the finite element method is a good design method, especially for the structural design of products. Its effect, such as saving design cost and shortens design cycle, is very significant. It has been favored by many designers in recent ten years.This paper complies with the principle of Design by Analysis, i.e. elastic stress analysis and plastic failure criterion, and uses finite element method and ANSYS software to perform stress analysis for the reinforced structures of Pressure Vessel of thin wall with large openings, in order to provide effective reference for product design. In order to examine the function of some variables, a series of three-dimension finite element models are established and then elastic stress analysis is performed, therefore, the characteristics of stress distribution are determined, and the general conclusions are made as follows:The high stress will be produced at the area of opening for pressure vessel with large openings. It is much securer to use Finite element analysis than pressure area method. It is available to make a comprehensive stress analysis for reinforced area and then evaluate the security by theory of Design by Analysis, so that a better reinforced structure can be designed. According to the verification of finite element method, when pressure area method is used to design, a certain space allowance should be kept, in order to ensure the structural safety and cost saving. By comparing a series of finite element models with different thickness ratio of shell and pipe, the influence on stress that made by the thickness ratio is worked out, so that a reasonable range of thickness ratio is inferred.