STRUCTURAL BEHAVIOUR OF TRUSSED-COLUMN BUILT UP USING THIN-WALLED STEEL PIPE

The availability of high strength steels leads to the use of metal steel pipe in truss-column
structure. The use of trussed column is not only restricted to beam support, but also
extends to various uses such as road sign, transportation of petroleum and gas product,
huge exhibition and many more. However, the use of thin walled steel pipes in composite
built-up truss-columns gives a rise to a certain major problems such as local buckling that
would appreciably reduce the strength and ductility performance of the members. This
paper describes an experimental study on the compressive strengths of built-up trusscolumn
using steel pipe sections. As the use of trussed column have gained momentum
due to its strength and aesthetic value, two types of trussed column were analyzed,
namely the triangular and rectangular trussed column, with different loading conditions
and depth variation. Investigated is the static structural behavior of such columns when
loaded by purely axial compressive concentrated forces acting at the supports. Geometric
and material nonlinear analyses are performed to investigate the critical local and postlocal
buckling strengths of steel plates under compression and in-plane bending. Initial
geometric imperfections and residual stresses presented in steel pipes, material yielding
and strain hardening are taken into account in the nonlinear analysis. Result were
tabulated and interpreted according to several parameters, such as weight,
compression/tension ratio, magnitude of forces and its distribution, along with deflection
of the trussed column. Comparison among the two trussed column (triangular and
rectangular) were presented and discussed.