Stress Classifications For Design By The Finite Element Analysis

This article analyses some typical parts of pressure vessels and calculates their stress intensity through finite element analysis methods on the basis of analysis standards of design.In this thesis, research works are done as follows.Firstly, according to classical mechanical principles, Typical parts of certain pressure vessels are analyzed and stress classification as well as the evaluation criteria of pressure vessels are discussed. Secondly, These parts are simplified reasonably and the finite element models are built through the software ANSYS. After defining all parameters and working conditions, general primary membrane stress, local primary membrane stress, primary bending stress, secondary stress and peak stress are obtained respectively from analyzing linear elasticity. Thirdly, stress intensity of these parts is analyzed in the elastic plastic case by using the same software to determine the self-controllable stress. Finally, By making comparison and analysis the calculations of analytical solutions, linear elastic and plastic solutions, it would draw the definite conclusions.Based on the above, the linearization results based upon accurate model parameters and proper grid density can completely satisfy requirements of stress classification. The linear tools within ANSYS could be easily accessible for evaluating strength of pressure vessels.This article also has discussed the effects of different finite element grid densities and structural geometry models on calculation results and stress classifications.This research will contribute from some extent to the design by analysis and the stress evaluation of pressure vessels using finite element method.