Study on Damage Diagnosis of Steel Grid Structure after Fire

The space grid structure is one of styles in largespace buildings. The damage analysis of space grid structure is an important part for repairing and strengthening after fire. A practical engineering was taken as the research object, and the development of members´ plastic strain during fire was studied by using ABAQUS. In addition, the paper defines three damage indexes D₁, D₂ and D₃, which were calculated based on equivalent plastic strain, displacement and the equivalent displacement separately. Through comparing the analysis results with the evaluation in the field after fire, the results show that D₃ is better to judge the damage of structures after fire.