The project established, for the first time, a damage identification method and damage severity criteria for steel structural members after fire, and proposed a method for determining the fire exposure temperature of members through metallographic analysis as well as a quantitative assessment method for the safety of steel structures after fire, filling the gap in the field of damage identification and safety assessment of steel structures after fire. Expert appraisal concluded that the research results are generally up to the international advanced level, with some reaching the international leading level.

　　Through fire exposure temperature determination of individual members, mechanical property analysis, chemical property analysis, and microstructure analysis, the research conducts damage identification and determines member damage grades. At the same time, based on the quantitative assessment method, it calculates the importance coefficient of each member and thereby derives the safety of the overall structure. It can achieve quantitative assessment of the damage condition and structural safety of steel structures after fire, providing a scientific and reasonable reference basis for their reinforcement and renovation.

　　In addition, based on the above assessment method, the project developed Android-based software for evaluating the residual load-bearing capacity and damage of steel structures after fire. The software can be installed on Android smartphones and enables real-time analysis of data collected at the fire scene, allowing rapid assessment of the residual load-bearing capacity and damage condition of steel structural members after fire. On the one hand, this improves work efficiency; on the other hand, it can guide technical personnel in promptly adjusting and refining appraisal plans, helping to improve the accuracy of assessment conclusions. The software has obtained a computer software copyright.