摘要
钢材高温蠕变是钢材在高温和应力作用下的塑性应变。高温蠕变会导致钢柱变形增大,耐火极限降低。为了考察高温蠕变对冷弯薄壁型钢柱抗火性能的影响程度,建立了考虑高温蠕变的抗火分析有限元模型,通过试验结果对有限元模型进行验证。利用模型研究了在不同荷载比、轴向约束刚度比、升温速率和火灾场景下,高温蠕变对冷弯薄壁型钢柱抗火性能的影响。研究表明,在有限元模型中考虑蠕变因素后,对于钢柱抗火性能的预测更为准确,更符合真实情况;在中等升温速率的火灾场景中,荷载比为0.3左右的无轴向约束钢柱因高温蠕变而引起的耐火极限的降低最为显著。
Creep is a plastic strain of steel under high temperature and stressed conditions.Creep can aggravate the deformation of steel column, and then reduce the fire resistance.In order on study the influence of high temperature creep on the fire resistance of cold-formed steel columns, a fire resistance finite element model considering creep is established, and the finite element model is validated using related test data.Finally, the effects of creep on the fire resistance of cold-formed steel columns under different load ratios, axial restraint stiffness, heating rates and fire scenarios are studied.The results show that after creep is included in the finite element model, the prediction on the fire resistance of steel columns is more accurate.In a fire with medium heating rate, the fire resistance of unrestrained steel columns with a load ratio of 0.3 decreases most significantly due to high temperature creep.
作者
杨竞杰
王卫永
YANG Jingjie;WANG Weiyong(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)
出处
《建筑钢结构进展》
CSCD
北大核心
2021年第7期67-75,共9页
Progress in Steel Building Structures
基金
国家自然科学基金(51878096)。
关键词
冷弯薄壁型钢
抗火
高温
蠕变
有限元分析
cold-formed steel
fire resistance
high temperature
creep
finite element analysis
