摘要
随着钢结构在建筑工程中发挥着日益重要的作用,其防火问题成为一个不可回避的重大课题。因此,钢结构在火灾温度场下的破坏机理研究显得尤为重要。本文假设火灾温度场为ISO834曲线,考虑热辐射和热对流共同作用的四面受火情况,通过有限元数值方法模拟了H型钢柱随时间变化的温度场分布。根据热传导得到的瞬态温度场,并且考虑到钢材物理特性随温度变化引起的材料非线性及几何非线性,进行了受压钢柱在不同约束条件下的热应力分析。论文分别对两端铰支、两端铰支且限制轴向位移等情况下,H型钢柱随温度变化的应力、位移等热响应进行了模拟计算。结果表明,轴向约束的提高在一定程度上降低了高温下钢柱的极限承载力及极限温度承载力。
As steel structures play more and more important roles in the constructional engineering, the fire safety problem turned to be an inevitable and significant subject. Thus, it was especially important to carry out the research on the failure mechanism of steel structures in fire. Based upon the assumption that the varying temperature field on the steel component is described in ISO834 temperature curves, and considering the interaction of radiation and convection in fire, the finite element method was used to simulate the temperature field of H-steel column. Then, based on the temperature field, and considering the influence of material nonlinearity and geometric nonlinearity on the thermal response of steel component, the thermal-stress analysis of compressive steel column under the different constraints was carried out. The thermal response of steel components are discussed, including the model of failure, the stresses and displacements of the component with the constraints that the both ends are hinged, and one end hinged and the other restrained axially, respectively. The results show that the enhancement of axial constraint contrarily brings down the ultimate bearing capacity and the critical temperature of the steel column in fire to a certain extent.
出处
《华中科技大学学报（城市科学版）》
CAS
2008年第4期70-72,80,共4页
Journal of Huazhong University of Science and Technology
基金
浙江省科技计划重点项目(2008C23013)
宁波市自然科学基金(2007A610060)
关键词
不同约束
H型钢柱
火灾行为
非线性分析
nonlinear analysis
different constraint
H-steel column
behavior in fire
