The stability of elastic elements in a deformed state with initial structural form imperfections for truss elements with rigid nodes was studied

Abstract

Abstract. Goal.The stability of elastic elements in a deformed state with initial imperfections of the structural form for truss elements with rigid and elastic nodes was studied. Method. The operation of compressed elastic elements of trusses with rigid welded joints is most accurately described by a model in which one support is rigid and the other has elastic resistance conditions. According to the methodology of the initial parameters, the analytical method from the solution of the differential equation of rod stability, a system of algebraic equations was obtained, which describes the stability of an elastic rod with initial imperfections and deviations. The results. Numerical studies of the deformed state of the elastic rod at various initial imperfections and deviations, force impact parameters, and support elasticity parameters were carried out. The impact on the deformed state of the elastic rod of the displacement of the supports, and the initial imperfections - angle of rotation of the support, as well as different stiffness characteristics of the elastic support, were studied. Numerical studies of the influence of the loading factor on the deformed state of the elastic rod have been carried out. The non-linear nature of the growth of calculated bending moments and maximum rod deflections has been established. In the case of longitudinal bending, the growth of the maximum bending moments when adopting the rod model occurs faster than the increase in the maximum deflections. Regularities between the deformed axis of the rod and the loading factor at different initial deviations of the rigid support are established. The developed and improved methodological approach makes it possible to determine the deformation state of centrally compressed rods with maximum deviations, obtained during the construction, installation, or operation of the structure.Scientific novelty. On the basis of generalized theoretical studies of the deformed state of a centrally compressed elastic rod, taking into account the initial imperfections and conducted numerical studies, the method of identifying regularities between the load-bearing capacity of the rod and the influence of maximum initial imperfections, Metod has been improved. Practical significance. The obtained results and the developed methodology make it possible to clarify the stress-strain state of elastic elements of trusses with rigid nodes, taking into account the revealed imperfections of the various initial imperfections and deviations, force impact parameters, and elasticity parameters supports.