Calculation of sealing joints with elastic edge in PTC MathCAD

Abstract

The article touches upon the issues of the development of engineering methods of calculating a thin-walled shell-plate seat for valve and flange sealing joints, followed by the formulation of tasks using modern automated calculation software. To achieve the purpose, the authors used Parametric Technology Corporation MathCAD (PTC MathCAD) with subroutines for the search for extremum of functions and the computational block ‘Given - minimize’. The calculation is presented in the form of algorithms consisting of three logically interrelated parts: 1) stiffness calculation; 2) strength calculation; 3) the calculation of rational dimensions. The obtained results of the calculation of geometric dimensions are tested, which eliminates a probable error in the calculated block ‘Given’ of PTC MathCAD. Among the developed engineering methodologies, the article describes the following ones: a method for calculating the rational geometrical dimensions of a shell-plate valve seat, operating under shock loading at an uncertain maximum dynamic load. It ensures that the allowable stresses in a thin-walled shell-plate seat are not exceeded. Another is a method for testing the stress-strain state of a shell-plate valve seat under static loading with a force of sealing and pressure of the working medium. The last one is the method of calculating rational geometrical dimensions of the shell-plate seat of a flange connection, which minimizes the unit stiffness (minimizing sealing force), provided that the shell-plate seat strength is ensured.