Q345钢轴心受力构件高温下设计参数与可靠度分析

我国现行的钢结构设计规范中提出了各类钢材常温下设计指标，但尚未有高温下的设计指标。为了分析高温下钢材的设计指标，收集了152组Q345钢材高温材料性能数据，得到Q345钢材高温下材料性能不定性的统计参数；利用ABAQUS建立有限元模型，计算高温下Q345轴心受力构件承载力360组，从而获得Q345钢轴心受力构件高温下计算模式不定性的统计参数；基于统计结果采用一次二阶矩法，通过MATLAB编制程序提出了Q345钢轴心受力构件高温下抗力分项系数。对提出的系数进行可靠度校核分析，结果表明，满足建筑火灾下的可靠度要求，具有较好的可靠性。

Design parameters and reliability analysis of Q345 steel axial loading member under high temperature

In current Chinese code for design of steel structures, the design values of all kinds of steel at mbient temperature have been listed, but there is no design value for steel at high temperature. In order to analyze the design values of steel under high temperature, 152 groups of mechanical properties of Q345 steel at high temperature were collected and the statistical parameters of material property uncertainties of Q345 steel under high temperature were obtained. The finite element model was established in the general finite element software ABAQUS to calculate the ultimate loading capacity of 360 groups of Q345 steel axial loading member under high temperature and the statistical parameters of model uncertainties of Q345 steel axial loading member under high temperature were generated. The partial factors for resistance of Q345 steel under high temperature were proposed by using the first-order second-moment reliability method which was programmed through Matlab and the reliability of the proposed resistance partial factors were checked. The result meets the reliability requirement of building in fire and have sufficient reliability.