Numerical Simulation of Plastic Buckling in Steel Cylinders Subjected To Cyclic Bending

Abstract eng:
Steel cylinders are used in numerous structural engineering applications, such as members of tubular lattice structures, or pipeline segments. The structural behavior of steel cylinders subjected to strong cyclic bending loading conditions (e.g. in the course of a strong earthquake event) is examined in the present study, through a rigorous numerical simulation, with special emphasis on the constitutive modeling of the steel material. Under bending loading conditions, the cylinder exhibits cross-sectional distortion, in the form of ovalization, combined with excessive plastic deformations, leading to instability in the form of local buckling (wrinkling) and, eventually, failure of the loaded member. Depending on the geometrical characteristics of the cylinder (D/t ratio), the instability phenomena may take the form of elastic or plastic buckling. The present study focuses on relatively-thickwalled cylindrical members, which exhibit local buckling in the plastic range of the steel material, with the use of advanced nonlinear finite element models able to describe both geometrical and material nonlinearities. Special attention is given in the cyclic plasticity material modeling. An advanced plasticity model that adopts the so-called “Bounding Surface” concept is employed. The model is calibrated through special-purpose material testing that describe the cyclic behavior of the steel material under reverse loading conditions, and it is implemented within the commercial finite element code ABAQUS. The numerical results refer to cylindrical members made of high-strength steel, and are compared with the corresponding results of other material models available in ABAQUS (e.g. linear and nonlinear kinematic hardening). An extensive parametric analysis is also conducted, aimed at determining the effects of geometrical characteristic of the cylinder on its plastic buckling performance. Finally, the validity of the numerical models is verified by comparison of the numerical results with relevant experimental evidence of cyclic bending tests on cylindrical members, conducted elsewhere.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket