三面受火钢筋混凝土梁温度场非线性分析

根据三面受火钢筋混凝土梁离散体积单元的能量守恒原理，建立了有限差分平衡方程，在合理确定混凝土热工参数基础上，采用增大混凝土质量热容的方法，考虑混凝土中自由水与结合水的物理化学反应对混凝土温度场的影响。通过编制三面受火钢筋混凝土梁截面温度场非线性有限差分程序，并结合火灾情况下钢筋混凝土梁温度场的试验结果，合理地确定了混凝土质量热容放大系数和混凝土表面换热系数的计算式。结果表明：三面受火钢筋混凝土梁温度场的计算结果与试验结果符合较好，为进一步研究火灾情况下钢筋混凝土梁力学性能和耐火极限提供了条件。

Nonlinear analysis of temperature field of reinforced concrete beam with three surfaces exposing to fire

The finite difference equation was built by using elemental energy balance of reinforced concrete beam with three surfaces exposing to fire based on the thermal properties of concrete.The influence of the physical or chemical reaction of free or combined water in concrete on the temperature field of concrete was considered by magnifying the specific heat of concrete.The program for drawing up the nonlinear finite difference analysis of the temperature field within reinforced concrete beam with three surfaces exposing to fire was developed,and the magnifying coefficient of the specific heat of concrete and the formula for the thermal capacity of concrete were determined by matching the numerical results with experimental results from references.The results show that the calculated results accord with the experimental results and it is possible for further researches on the behaviors and fire resistance of reinforced concrete beam under fire condition.