Buckling Analysis and Stability of Compressed Low‐Carbon Steel Rods in the Elastoplastic Region of Materials

Abstract

is paper presents new approaches for solving a problem of the stability of compressed rods in the elastoplastic working region of materials. It is known that the columns of buildings, supports of engineering devices, drill rods of oil, and gas extraction industry may be subjected to significant risk of stability loss. Nowadays, there are design methods based on test results defining the relations (e.g., critical stresses-slenderness) to avoid this risk due to stability loss, but the precision and limits of definition are not always known. e main objectives of the study were to develop new approaches that would allow specifying the values of critical stresses of compressed elements beyond the proportional limit. e problem of stability of the compressed elements in the elastoplastic region was studied according to the stability theory. e authors suggested an original approach to the issue; in particular, the determination of values of the critical stresses and the finding of the points of the bifurcation were carried out by the tangent established by experimental results and by the approximation of the so-called double modulus. Comparative analysis showed the advantage of the proposed approach, particularly that the new critical curves were located below the curves of Engesser-Karman and Shanley and above the critical curves established by building codes. A new approach for the determination of critical stresses in the elastoplastic region was developed through which the structural reliability and economic efficiency was increased by almost 12% compared to the existing approaches.

3D Printed Hollow Off-Axis Profiles Based on Carbon Fiber-Reinforced Polymers: Mechanical Testing and Finite Element Method Analysis

“…Under compressive loading, it is difficult to maintain a uniform tension throughout the test specimen throughout the test. Changing the wall thickness of the sample leads to differences in resistance to loss of stability [ 47 , 48 ]. A combination of pressure and bending is used to calculate the critical force of off-axis hollow sections, so-called geometrically imperfect rods.…”

“…The buckling test is one of the commonly used mechanical tests, which are based on the deformation of a test specimen by pressure to determine the critical force of stability failure. The test specimen is clamped in the jaws of the tensile testing machine, where it is loaded with a constant force, usually until failure (collapse of the structure) [ 48 ].…”

Heuristic Optimization of a New Type of Prestressed Arched Truss

“…The primary structure is an arched truss and represents a rod system. It has an upper chord (1)(2)(3)(4)(5)(16)(17)(18)(19)(20), a lower chord (6-7-8, 21-22-23), a lattice-vertical and diagonal elements (9)(10)(11)(12)(13)(14)(15)(24)(25)(26)(27)(28)(29), support nodes (1,14), strut nodes (7,16) and loading nodes (2)(3)(4)(5)(6)(16)(17)(18)(19)(20). The slender part is a tie member-cable (30).…”

“…Thus, prestressed steel structures are widely used to disperse seismic energy in earthquake zones, decrease the structure's mass, and raise the fatigue strength of the system. These considerations are especially relevant in long-spanning elements and high buildings, considering the challenging technological load [3,4].…”

“…It describes how problems with the prestressing might manifest themselves and whether anything could be monitored to determine whether corrosion was occurring. In the literature [3], authors considered buckling analysis of columns out of the elastic region of the material. The behavior of prestressed trusses has also been explored [22,[32][33][34][35][36][37].…”