Features of the study of threaded joints using the finite element method

Abstract

A significant number of computer programs exist today for various engineering calculations, research and development of equipment elements. The SolidWorks software has become widespread for such work, which allows you to minimize time, facilitate the performance of the necessary work, as well as analyze the strength, stiffness, stability and endurance of products of a wide range of complexity and purpose. The program uses the finite element method, which has both a number of advantages and certain disadvantages.

To investigate the possibilities of such a program, a model of a threaded connection of sucker rods has been built. Simulation of make-up torque for threaded connections remains problematic when modeling in SolidWorks Simulation. There are several ways to simulate the make-up moment during the study of the stress-strain state of threaded connections. To solve problems in an axisymmetric setting, the optimal method is to overlap the ends of the nipple and coupling by the required amount. The use of an axisymmetric model in the process of simulation does not impair the results obtained in comparison with 3D models. But it speeds up the calculation process, allows you to build a fine mesh of finite elements and get more accurate results.

The paper presents an algorithm for calculating the tension of the threaded connections of sucker rods, which can be applied to threaded connections of drill string elements with some adjustments. The only difference will be in the formula for determining the make-up moment, from which the value of the pre-tightening force and the areas of dangerous sections are derived. Also, in the work, a simulation study was carried out using the selected method using the example of a threaded connection of sucker rods with a diameter of 19 mm. A diagram of displacements and distribution of equivalent stresses in a threaded connection was obtained and the possibility of determining specific parameters at certain points of the model under study was shown with subsequent automated construction of their graphical dependencies.