Residual bending bearing capacity assessment of reinforced concrete column under cyclic loading based on fiber-beam element

Most damaged reinforced concrete (RC) frame structures still can be used after earthquake, it is important to assess the residual performance of damaged structures. However, quantitatively evaluate the residual performance of damaged structures still presents difficulties due to the lack of suitable indicators. For studying and estimating the residual bending bearing capacity (RBC) of RC columns under cyclic loading properly, a new method is proposed, which is characterized based on fiber-beam element damage in section. Firstly, two quantitative indexes, fiber damage index (FDI) and section damage index (SDI) based on fiber-beam elements, are suggested. Weak section (the most damaged part on column) of RC column can be determined utilizing the SDI. Moreover, based on comparison between test and calculation, the section damage status of RC column can be described by FDI. And then a procedure for obtaining RBC considering the damage of the RC column is also introduced, and taking a RC column specimen as an example to realize and examine the whole calculation procedure proposed. Furthermore, for determining RBC of testing specimen, a rule for determining the failure point of RC columns under cyclic loading is proposed and verified. By comparing the RBC determined by the experiment and the calculation of 21 RC columns in the Pacific Earthquake Engineering Research Center structural performance database(PEERSPD), our suggested method of computing the RBC is verified too, which proves that new method can quantitatively assess the performance of the members under cyclic loading.

Automated summary

A new method based on fiber-beam element damage in section is proposed to evaluate the residual bending bearing capacity of damaged RC columns under cyclic loading. Quantitative indexes FDI and SDI are suggested to determine weak section of RC columns, describe section damage status, and calculate RBC. Experimental verification shows that the new method can accurately assess the performance of members under cyclic loading.