Seismic energy dissipation finite element analysis and damage quantitative evaluation of reinforced concrete frame structure system

The damage of reinforced concrete (RC) frame structures during seismic events is frequently severe, potentially resulting in significant casualties and substantial economic losses. Therefore, the investigation of collapse mechanism and quantitative damage assessment for frame structures subjected to earthquakes is of great significance. Using ABAQUS software, a three-dimensional solid finite element (FE) model of a 3-story, 2-span reinforced concrete plane frame structure was established. Based on good verification with pseudo dynamic tests, a full-scale model of the 5 and 10 story 3×3 span reinforced concrete space frame structure system was subsequently developed for seismic wave elastic-plastic time history analysis. The critical thresholds for "energy damage" and "stiffness damage" corresponding to the five states of "small earthquake elasticity", "moderate earthquake elastic-plastic", "large earthquake small plasticity", "maximum earthquake large plasticity", and "failure". The results show that: (1) as the local seismic wave acceleration increases, the absolute displacement of floors, the displacement angle between floors and the total plastic energy dissipation value of the frame structure all increase, and the energy dissipation ratio of columns gradually increases while that of beams and slabs decreases; (2) under the influence of ultimate seismic wave, plastic hinges initially appear at the column end and then at the beam end in both frames. The failure mode is that the concrete is crushed when it reaches the axial compressive strength, and the reinforcement is pulled off when it reaches the ultimate strain; (3) the damage assessment method used can accurately and quantitatively evaluate the extent of seismic damage to concrete frame.