Buckling of Cracked Beam-Columns Due toRepetitive Axial Loads

The strength of a component or structure can be significantly reduced by the presence of cracks. This kind of structural damage will accumulate over time, leading to significant decrease in ultimate load carrying capacity of structural members. In this paper, a parametric study is implemented in order to evaluate buckling load of fatigue degraded beam-columns. For this purpose, the cracked beam-column is considered as two separate elastic columns connected by a rotational spring at the cracked section. The critical load of a cracked rectangular beam-column is calculated and simplified equations are provided for different end conditions. Considered end conditions include: pinned-pinned, fixed-pined, fixed-free and fixed-fixed. The effect of different parameters are evaluated on the buckling load of cracked beam-columns. Finally, the effect of repetitive loads on axial load carrying capacity of such columns is studied. Results show that the critical buckling load of cracked beam-columns decreases under repetitive loads.

کلیدواژه ها:

Beam-Column ، Crack ، boundary condition ، repetitive loads.