Analytical Prediction and Finite Element Simulation of Steel Tubular Pier with Stiffener

Hollow steel tubular members are extensively used in multi storey car parks, bridge piers, building columns, offshore structures and subway columns. An earthquake of moderate intensity can result in extensive damage and potential collapse of bridges. During a large earthquake, traditional seismic lateral resisting system can experience significant damage and it cause residual drifts. Thus, a suitable strengthening or retrofitting technique needs to be developed for minimising structural damage and human casualty due to imposed lateral impact loading. The steel shell acts as longitudinal and transverse reinforcement. The primary role of stiffeners is to prevent local buckling prior to overall buckling and to increase overall buckling strength. In seismic applications, an additional, yet equally important role of stiffeners is to increase ductility of the cross section under cyclic loading. Stiffeners are the secondary plate or sections which are attached to web or flanges to stiffen them against out of plane deformation. This paper presents the research work on analytical prediction and finite element simulation of steel tubular pier with stiffeners. A non-liner 3D model was developed using ANSYS programme.

Numerical investigation of post-critical resistance of hollow circular cross-section bars under bending and axial compression

Analysis results of hollow circular cross-section bars under bending and axial compression by the finite element method in different formulations with considering of overall buckling described. Qualitative comparison of the data obtained with the data of laboratory tests is made. Analysis parameters allowing achieving an optimal balance between analysis accuracy and speed are given.

Overall buckling prediction model for fibre reinforced plastic laminated tubes with balanced off-axis ply orientations based on Puck failure criteria

Fibre reinforced plastic tubes with balanced off-axis ply orientation exhibit excellent mechanical properties and are widely used in various types of structures. In this study, a theoretical prediction model was proposed to determine the overall buckling load and the failure mode of fibre reinforced plastic laminated tubes with off-axis ply orientation under axial compression. This model considers the transverse shear effect and adopts Puck failure criteria to perform an analysis based on deduced three-dimensional stress and strain fields. A series of carbon fibre reinforced plastics tubes with varying off-axis ply orientations and lengths were designed and prepared. Axial compression tests with effective end-reinforcement and hinge support were performed to validate the proposed prediction model. The results indicated that the predicted model results were in good agreement with the test results, with respect to ultimate loads, failure modes, and locations of failure. Parametric analysis on the influence of transverse shear effect was also conducted, which further explained the influencing degree of transverse shear effect considering different tube lengths, ply sequences, and initial deflection.

Finite Element Modeling of Back-to-Back Built-Up CFS Un-Lipped Channels under Axial Compression

A finite element model is described in this paper, which investigates the behavior of CFS built-up un-lipped channel sections, connected back to back with the help of intermediate web fasteners, subjected to axial load. Finite element package ABAQUS was used to develop the model for built-up columns, which were validated against the test results reported by the authors recently on another paper. Material non-linearity and initial imperfections were included in the FEA model. A parametric study was conducted using the validated FEA model to investigate the effect of screw spacing on axial strength. Axial strengths obtained from the FEA model were compared against the AISI&AS/NZS design strengths; obtained comparisons showed that the AISI&AS/NZS standards were un-conservative for stub and short columns which failed by local buckling whereas the standards were over-conservative for columns failed through overall buckling.