Mathematical modeling of the strength of the stud connection of assembly plates of the crystallizer of CCM

The most critical unit when casting steel in a continuous casting machine is the mold. The most widespread are composite molds, convenient in operation and manufacture, consisting of a copper working wall with slotted channels and a steel outer casing. In industrial designs of composite molds, the connection of copper and steel plates is carried out by means of many steel pins, and they are extremely unevenly located along the surface of the plate due to the presence of cooling channels, dowels and a seal. The aim of the work is to create a mathematical model to determine the coefficient of uneven loading of the studs and the safety factor of the connection of copper and steel plates for a given design of the prefabricated mold and the selected typical parameters of the stud connection. The unequal loads on the studs were taken into account by calculating the coefficient of unevenness. It was believed that the maximum tensile force per stud is proportional to this coefficient and the average tensile force. For each hairpin, a cluster was identified, including a given number of hairpins closest to it. The average distance in the cluster, the average value of the distance across all clusters, and the relative distance for the cluster associated with a particular hairpin were determined. The load on the threaded connection is proportional to the area of the connected plates, which are held by the stud, therefore, it was assumed that the coefficient of unevenness of the load for a given stud is proportional to the square of the relative distance. An example of calculating the load non-uniformity coefficient for the considered design of an industrial prefabricated crystallizer is shown. A mathematical model is presented to determine the safety margin of the stud connection of the copper and steel plates of the mold, as well as the required tightening torque of the stud, which ensures the joint will not open. The calculations took into account the maximum test pressure of water and the maximum external shear force during friction of the ingot against the wall of the mold. A computer program has been created that makes it possible to analyze the reliability of the connection between the steel and copper walls of the mold of the continuous casting machine when simulating various situations, including force majeure and emergency situations.