# Damage Analysis of Reinforced Concrete Columns Based on Fiber Beam-Column Element
## 4 Analysis of the Seismic Damage Process of the Reinforced Concrete Column  
In order to study the failure process of the specimen mentioned above and increase the damage response of the specimen, the amplitude of the ground motion was adjusted to 1.2 times of the ground motion record for input.  
The displacement response is shown in Figure 15. Due to the increasing amplitude of ground motion, the displacement response of the specimen also increased greatly. At 2.58 s, the displacement in the X-direction reached a maximum value of 174.50 mm. At 2.71 s, the displacement in the Y-direction reached the peak value of \(-244.51\) mm.  
Figure 14: Final damage distribution of the specimen. (**a**) Tensile damage; (**b**) Compression damage; (**c**) Test result [31].  
The tensile damage of concrete at different times is shown in Figure 16. The ordinate represents the height of the specimen. At 0.67 s, tensile damage occurred at all positions of the bottom of the specimen. The damage on the right side was greater than on the left side. The damage at the bottom of the specimen was the largest. At 1.10 s, the bottom of the specimen was fully damaged by tension. The height of the local damage reached 600 mm. At 2.04 s, the tensile failure occurred at a height of 500 mm at the bottom of the specimen. The most severe damage area changed from the middle lower part of the specimen to the right lower part. At 2.58 s, the displacement in the X-direction reached the maximum. Tensile failure occurred at a height of 600 mm at the bottom of the specimen. The height of tensile failure of the lower right part of the specimen reached 800 mm. At 2.71 s, the displacement in the Y-direction reached the maximum. The tensile failure range of the lower right part of the specimen increased slightly on both sides. The damage gradually developed to the upper part of the specimen. After that, although the specimen was still subjected to the earthquake, only the local tensile damage of the specimen increased slightly. At 7.75 s, the tensile damage of the specimen reached the final state. Although the ground motion continued, the damage did not continue to develop. At this time, the damage index in most areas of the specimen exceeded 0.5, and only a very small area at the top had less damage.  
The compression damage of concrete at different times is shown in Figure 17. The ordinate represents the height of the specimen. At 1.05 s, compression damage occurred in all areas of the bottom of the specimen, but the degree of damage was small. Only the small area on the lower right had large compression damage. At 2.04 s, compressive failure occurred in the middle of the bottom of the specimen and in the edges of both sides. The damage height was within 200 mm. At 2.58 s, the displacement in the X-direction reached maximum. The bottom compression failure areas increased in a wide range. The height of some compression failure areas was close to 500 mm. At 2.71 s, the displacement in the Y-direction reached maximum. The range and degree of compression damage only increased slightly. After that, the damage of the specimen slowly developed. At 5.43 s, only compressive damage in the lower left region of the specimen increased slightly. At 7.75 s, the damage of only a small part of the specimen increased slightly. At this time, the compressive damage of the specimen reached the final state. Although it was still subjected to ground motion, the damage did not continue to develop.  
Figure 15: Time history of displacement. (**a**) X-direction; (**b**) Y-direction.  
Figure 16: The tensile damage of concrete. (**a**) At 0.67 s; (**b**) At 1.10 s; (**c**) At 2.04 s; (**d**) At 2.58 s; (**e**) At 2.71 s; (**f**) At 7.75 s.  
Figure 17: The compression damage of concrete. (**a**) At 1.05 s; (**b**) At 2.04 s; (**c**) At 2.58 s; (**d**) At 2.71 s; (**e**) At 5.43 s; (**f**) At 7.75 s.  
The damage of the steel bars was found to be very small and the maximum damage index is only 0.05, which was not analyzed separately.