Research Of Critical Pressure Calculation Method In External Pressure Slant Conical Shell Vessel Without Hem

The stability is the primary problem that should be considered in the design of external pressure vessel. In the ASMEⅦ-2010and GB150-2011, they are according to methods and theory of the cylinder and conical shell. There is not independent design calculation method for slant conical shell. This paper is about with analysis and research for external pressure slant conical shell, including of rationality of design method, the problems existing in the design method, the improved design method, and fitting the function relational expression between critical pressure and structural parameters. There are three parts of research content in this paper.1. Verify the reliability and rationality of design method in external pressure slant conical shell. According to the GB150, the slant conical shell is designed on the calculation method of conical shell. After analysis this method, we found the equivalent conical shell was subjected less external pressure than the slant conical shell, resulting in the design thickness of slant conical shell was thicker.2. Improve design method of external pressure slant conical shell, making design thickness more reasonable. Find a conical shell is subjected similar external pressure with the slant conical shell, namely the conical shell having different cone angle with slant conical shell. The new equivalent conical shell is subjected similar external pressure with the slant conical shell, thus improved the original design method. It can meet the design requirements and save material.3. Fitting the critical pressure calculation formula. Through compare the relationship between critical pressure and various parameters, use multiple linear regression method to establish relationship of function between critical pressure and influence factors, established the linear regression model. Use the least square method to solve coefficient, and use Origin software to solve multiple linear analysis results, estimation and test the significant of fitting equation, get the function relational expression between critical pressure and influence factors.At home and abroad, there isn’t too much research for slant conical shell. This research is just a part of slant conical shell. And many aspects need to fill. These researches will be a huge help to slant conical shell design and calculation.