钢筋混凝土柱火灾后偏压力学性能有限元分析
Finite element analysis of eccentrically compressed performance of reinforced concrete columns after fire
林晓康1
作者信息
- 1. 健研检测集团有限公司 福建厦门 361004
- 折叠
摘要
建立钢筋混凝土柱温度场和火灾作用后偏压受力性能的有限元分析模型,有限元计算的破坏形态、荷载-变形曲线、承载力和试验结果吻合良好.同时,分析了圆形截面和方形截面偏压柱的温度变化和受力特性.结果表明,与外表面相同距离点的方形截面温度比圆形截面温度低;受高温和应力作用,偏压柱混凝土最大压应力和拉应力不在截面最外边缘,而是出现在左右半部中间附近,并且随着挠度增加,最大压应力位置向受拉侧偏移;受火时间小于90 min时,钢筋混凝土柱承载力和刚度随受火时间增加快速下降,而后下降平缓;火灾后剩余刚度系数小于火灾后剩余承载力系数,受火时间90 min时,钢筋混凝土柱火灾后剩余承载力和刚度系数分别约为0.45和0.37.
Abstract
Finite element(FE)analysis models were established for the temperature filed and eccentrically compressed performance of rein-forced concrete columns after fire exposure.The failure mode,load-deformation curve,bearing capacity calculated by FE method were in good agreement with the experimental results.An analysis was conducted on temperature changes and mechanical characteristics of circular and square eccentrically loaded columns.The results indicate that the temperature of the square section at the same distance from the outer surface is lower than that of the circular section.Under the influence of high temperature and stress,the maximum compressive stress and tensile stress of concrete in the eccentrically loaded column do not occur at the outermost edge of the section,but near the middle of the left and right halves.As the deflection increases,the position of the maximum compressive stress shifts towards the tensile side.When the fire exposure time is less than 90 min,the bearing capacity and stiffness of reinforced concrete columns decrease rapidly with increasing fire ex-posure time,and then decrease gently.The residual stiffness coefficient after fire is smaller than the residual bearing capacity coeffi-cient.After a fire exposure of 90 min,the residual bearing capacity and stiffness coefficients of reinforced concrete columns are about 0.45 and 0.37 respectively.
关键词
钢筋混凝土柱/火灾后/有限元分析/温度场/承载力Key words
Reinforced concrete columns/After fire/Finite element analysis/Temperature field/Bearing capacity引用本文复制引用
出版年
2024
NETL
NSTL
万方数据