火灾后空间混凝土框架结构的受力性能模拟

Numerical Simulation of Mechanical Performance of Spatial Concrete Frames after An Experienced Fire

为了分析火灾后空间混凝土框架结构损伤、修复和加固后的力学性能,基于纤维单元模型和分层壳单元模型,将梁、柱构件截面划分成多个纤维,将板沿截面厚度方向划分成多个层,可以考虑各个构件截面的不均匀温度场分布以及受火损伤或修复、加固后材料力学性能的变化。以ABAQUS通用有限元软件为开发平台,利用Python脚本语言对其进行二次开发,建立混凝土框架火灾受损分析系统(ASFCF)。进一步以一个多层多跨空间混凝土框架结构为例,利用该系统对框架在受火损伤、修复和加固后的力学反应进行了研究和对比分析。结果表明,ASFCF系统可以较为准确地进行火灾后空间混凝土框架的损伤、修复与加固后的力学性能分析。研究成果可作为评估混凝土整体框架结构火灾后的残余力学性能及修复、加固后的力学性能的理论参考。

In order to analyze the mechanical performance of damaged,rehabilitated and strengthened spatial reinforced concrete frames after an experienced fire,two classical numerical models,i.e.the fiber element model and the layered shell element model are adopted in this paper to divide the cross section of beams or columns into concrete or steel fibers and the cross section of slabs into several layers in the direction of section thickness.These models can simulate the nonuniform temperature distribution across the section and the change of the mechanical properties of fire-damaged,rehabilitated and strengthened materials.Based on the platform of ABAQUS Software,the further development is promoted with the language of Python to build the Analytical System of Fire-damaged Concrete Frame（ASFCF）.A multi-story,multi-span spatial reinforced concrete frame after fire is taken as a case to analyze by use of ASFCF to research the mechanical responses of the concrete frame under three conditions of fire-damage,rehabilitation and strengthening.The results indicate that ASFCF can soundly analyze the mechanical properties of damaged,rehabilitated and strengthened spatial reinforced concrete frames after fire and it provides theoretical references for evaluating the residual mechanical properties and the mechanical behaviors of rehabilitated and strengthened concrete frames after fire.