钢管混凝土柱—钢梁平面框架抗火性能数值模拟-结构工程专业论文.docxVIP

西南科技大学硕士研究生学位论文 第1页 摘 要 随着钢管混凝土组合结构在工程上的广泛应用，其抗火性能也受到越 来越多的关注。目前对钢管混凝土组合结构抗火性能的研究大都集中在单 独构件上，对整体结构的研究较少，现有研究表明构件的抗火性能与整体 结构抗火性能的差别较大，很难反应整体结构的抗火性能。 本文采用数值模拟方法，利用有限元软件ANSYS计算分析了无保护 层的3层3跨钢管混凝土柱一钢梁平面框架在局部受火条件下的抗火性能。 运用顺序耦合方法对结构进行了热一结构耦合分析，得到了梁柱温度场分 布规律、结构的耐火极限及临界温度。同时还对影响结构抗火性能的因素 进行了分析。 计算结果表明，钢梁在三面受火情况下，腹板温度最高，上翼缘温度 最低。由于热传导作用，梁整个截面的温度逐渐趋于一致。单面受火的钢 管混凝土柱，其截面温度分布为单轴对称，因柱外围钢管升温速率大于混 凝土，从而使柱截面温度场分布呈凹形。 竖向位移对结构是否达到抗火极限状态起控制作用。结构受火达到极 限状态时，钢梁除产生过大挠度，同时会产生一定的扭转变形，梁端下翼 缘会出现局部屈曲，塑性铰首先出现在梁端；柱水平位移较小，可有效降 低结构发生整体倒塌的可能性。 结构不同受火位置、荷载比以及长细比对结构整体抗火性能影响较 大，柱含钢率对整体结构抗火性能无明显影响。 关键词：钢管混凝土 组合平面框架 温度场 抗火性能 数值模拟  西南科技大学硕士研究生学位论文 第1I页 Ab st r act Nowadays，with the widespread use of the concrete filled steel tube composite structure in the engineering，its fire resistance performance has received more and more attention．Now most researches of fire resistance performance have been implemented for the isolated component rather than the whole structure．However，the research showed that the fire resistance performance of the isolated component iS different from that of the whole structure，thus the fire resistance performance of the isolated component cannot describe that of the whole structure． In this paper，the fire resistance performance of a three．1ayer and three-cross planar frame without fire protection material，which is composed of concrete filled steel tubular columns and steel beams，was analyzed under local fire by ANSYS．After analyzing the structure with the method of thermal —structural coupling，the regularity of temperature field distribution of beams and columns，the fire endurance and critical temperature of the structure were obtained．Meanwhile，the factors of the fire resistance performance of the whole structure were studied in the paper． The results indicate that the highest and lowest temperature appeared at the top flange and the bottom flange for the steel beams in three．side fire， respectively．Because of the effect of heat conduction，the temperatures of the steel beams becom