Calculation of a thin-walled seal of reduced stiffness

Abstract

The variety of occurring constructive solutions using thin-walled metal seals indicates the interest of valve manufacturers in joints of this type. As a rule, in such connections, the metal seal has the form of a thin-walled cylindrical shell. Along with a number of advantages, seals of this type are sensitive to loading conditions. When designing, the dimensions of the thin-walled shell are unknown (first of all, its thickness), which makes it impossible to determine the dynamic force that occurs when the valve is actuated. Experimental selection of the dimensions of a thin-walled shell is associated with significant financial and time costs. The area of rational dimensions for a thin-walled shell under certain operating conditions is quite narrow and can lead either to a loss of strength or to a loss of positive qualities (for example, the choice of shape deviation) by such a seal. One of the ways to improve such seals is to lower the reduced stiffness of the shell. Structurally, this can be done by connecting the shell and the plate (shell-plate saddle), or by giving it some other more complex geometric shape. However, the lack of scientific methods for choosing rational geometric dimensions, especially under conditions of dynamic (impact) loading, hinders the widespread use of such seals. The presented article is devoted to the issues of choosing the optimal geometric dimensions (thickness), provided that the strength of thin-walled metal seals (shell-plate) is ensured and the positive qualities inherent in metal-polymer compounds are preserved. In order to reduce labor and time costs, the calculation of the geometric dimensions of a thin-walled seal (plate and shell thickness) was automated in MathCAD.