This study conducted centrally and eccentrically axis compression test of H-shaped steel column with bonding methodology for unification of the H-shaped steel and the strengthened section as a main variable when strengthening the flange section of the H-shaped steel with poor member force by steel plate. The study examined structural characteristics such as behaviors, maximum stress, and deformation of the compressed column depending on eccentricity and applicability of H-shaped steel flange bonding methodology. And the result is as following.
1) As a result of H-shaped steel column test, the non-strengthened specimen compressed with the central axis showed brittle failure by buckling after having maximum load. But specimen of flange strengthened with steel plate showed increase of yield load, deformation in maximum load and failure by compression and buckling
The non-strengthened specimen compressed with the eccentric axis showed buckling from the initial compression because of eccentricity and failure in maximum load showing plastic moment. The specimen of flange strengthened with steel plate showed increase of stiffness according to strengthening, despite eccentricity, and bucking was shown and after the buckling, it showed plastic moment and failure with plastic buckling.
2) The maximum load of the strengthened specimen increased by 12.4~75% in the central axis and by -5.4~103.3 in the eccentric axis than the standard specimen.
3) The section area maximum stress of strengthened specimen decreased by 6.8~40.1% in the central axis and by 50.4% in the eccentric axis in high tension bolt jointing than the standard specimen. And it increased by 0.2~8.3% in specimen strengthened by other methods.
When compared specimen compressed with the central axis to specimen compressed with the eccentric axis, the stress is considered to decrease by eccentricity as the section area stress decreased by 39.2% in standard specimen, by 30.2%, in A type, by 26.8% in B type, by 57.4% in C type, and by 29.3% in D type for specimen compressed with the eccentric axis than for specimen compressed with the central axis.
4) As for ductility, strengthened specimen compressed with the central axis increased by 36.2~162.2 and strengthened specimen with eccentric axis increased by 115.7~361.2% than standard specimen. And ductility was the highest in the specimen strengthened by high tension bold jointing.
5) As for stiffness, the initial stiffness of the strengthened specimen compressed with the central axis increased by 12.4~63.3% than standard specimen, but stiffness of plastic region tended to decrease. The stiffness of strengthened specimen compressed with the eccentric axis was reduced by 6.9% as for initial stiffness and by 44.1% for stiffness of plastic region when the specimen was strengthened by high tension bolt joining. But the initial stiffness increased by 145.9~369.3% and the stiffness of plastic region increased by 37.2~144.3% in other strengthened specimen.
6) Exceeding the maximum load, the specimen compressed with the central axis showed fracture after maximum load in jointing methods combining welding and bolts other than high tension bolt joining, but the specimen compressed with the eccentric axis showed brittle failure by buckling presenting plastic moment. As for the strengthening effect on H-shaped steel according to strengthening methods, combining joining by welding at both extremes and joining high tension bolts(D type) was the best, and followed joining by welding at both extremes and center(B type), and joining by welting at both extremes(A type), and joining by high tension bolts(C type) because of the distance between strengthened joining and joined part.
Consequently, when strengthen a flange section of H-shaped steel column, the methods of combining joining by welding and by high tension bolts can most increase stress. And to apply this result to real structure, further study according to various slenderness ratios will be necessary.