木梁温度场及受火后力学性能数值模拟

Numerical simulation of temperature field and mechanical properties after fire of timber beams

运用有限元软件ABAQUS建立四面受火下木梁温度场模型和热-力耦合模型,对截面的温度分布、炭化速率、受火后剩余承载力进行分析并与试验对比。结果表明,木梁的温度场模型能较好地模拟出拐角处呈圆弧状的现象;四面受火下水平方向平均炭化速率为0.87 mm/min,竖直方向平均炭化速率为0.86 mm/min且含水率对炭化深度影响不大;木梁的受火时间对受火后剩余承载力影响较大。

The finite element software ABAQUS was used to establish the temperature field model and the thermo-mechanical coupling model of the four-sided fired timber beams. The temperature distribution, carbonization rate and residual bearing capacity of the fire were analyzed and compared with the test. The results showed that the temperature field model of the timber beam simulates the arc at the corner;the average carbonization rate in the horizontal direction is 0.87 mm/min under four sides, and the average carbonization rate in the vertical direction is 0.86 mm/min;the water content has little effect on the carbonization depth;the fire time of the wooden beam has a great influence on the residual bearing capacity after the fire.