【摘要】 对国内进行的恒高温下C20~C80强度等级的混凝土单轴受压力学性能的试验资料进行了重分析,提出了恒高温下C20~C80强度等级混凝土轴心抗压强度、受压弹性模量、受压峰值应变等力学性能指标统一计算公式和混凝土轴心受压应力-应变全曲线计算公式。并进一步建议了恒高温下钢材的多轴弹塑性本构模型和混凝土轴对称三轴受压本构模型,应用连续介质力学建立高温下钢管混凝土同时受压的同心圆柱体计算模型,采用弹塑性全过程分析理论,编制相应的计算程序,对恒高温下钢管混凝土轴压短柱受力性能进行全过程分析,计算结果与试验结果符合较好。更多还原

【Abstract】 Based on test results of compressive mechanical properties of C20～C80 concrete under unaxial compression and at high temperature,a formula for stress-strain curves of C20～C80 concrete and several empirical calculation formulas for axial compressive strength,elastic modulus and peak strain at high temperature were suggested.Furthermore,the constitutive models of steel under multiaxial stress conditions and plain concrete under axisymmetric triaxial stress conditions of axial compression and lateral confinement at high temperature was suggested.The calculation model of concentric cylinders of circular steel tube with concrete core under simultaneous compressive loading and high temperature was presented based on continuum mechanics.Applying elasto-plastic analysis theory,a FORTRAN program was developed and the concrete filled steel tubular(CFST) stub columns at high temperature were analyzed,and the analysis results were in good agreement with the experiment ones from references.更多还原