Kozlova O. Effect of residual stresses on the stability of compressed elements of trusses made of steel pipes

The purpose of these studies is to carry out experimental tests on the stability of compressed tubular bars with adjustment of the residual stress state by surfacing idler rolls along a cake. The results of theoretical and experimental studies in the field of RSS determination and its influence on the bearing capacity and deformability of compressed elements from steel pipes are analyzed and summarized. The method is developed and experimental researches are carried out on the influence of RS, which arise in the elements of pipes after the regulation of RSS, on their stability and deformability. Adjustment of the RSS of the compressed elements of the pipes gives an opportunity to increase the stability to an average of 20%. The method of determination of welding parameters for RSS regulation, as well as determination of the necessary amount of heat supply for surfacing of idle rollers, taking into account the RD for the elements of pipes, is developed. The samples after surfacing the blank rollers had virtually no initial deflections. The method of calculating the stability of compressed elements from steel pipes with the consideration of regulation of RSS by the surfacing of the idle rollers by the creature was developed. The proposals on the technology of fabricating metal constructions made of steel pipes with rational, from the position of increasing the bearing capacity, RSS, as well as the reinforcement of the elements of trusses from pipes in existing building metal structures have been developed.