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木材是可燃性材料,研究木构件的抗火性能具有重要意义。受火后木材表面发生炭化,由于炭化层的导热系数较低,木材表面的炭化层能减缓热量传递并延缓木材燃烧,因此木材受火后传热是一个非常复杂的问题。采用ABAQUS较系统地研究了木构件的截面温度场分布规律,为木构件抗火性能研究提供基础。模型中木构件采用二维平面单元模拟,材料的热工特性参数根据欧洲规范(EN 1995-1-2)取值。分别采用三面受火木梁和四面受火木柱试验结果对数值模型的可靠性进行验证,并进一步研究了木材干密度和含水率对木构件温度场分布的影响。研究表明,材料密度越大,截面相同位置处的温度越低,截面温度上升越慢;而含水率对截面温度分布影响较小。
Wood is a flammable material, research fire resistance of wood components of great significance. Due to the carbonization of the surface of the wood after the fire, due to the low thermal conductivity of the carbonized layer, the carbonized layer on the surface of the wood can slow the heat transfer and delay the burning of the wood. Therefore, the heat transfer of the wood after being exposed to fire is a very complicated issue. ABAQUS more systematically studied the temperature distribution of the cross-section of wood components of the law of fire-resistant wood components to provide the basis for the study. The wood components in the model are modeled using two-dimensional planar elements and the thermal properties of the material are to be in accordance with the European directive (EN 1995-1-2). The reliability of the numerical model was verified by the test results on three sides of firewood beams and four sides of firewood columns. The effects of wood dry density and moisture content on the temperature field distribution were also studied. The results show that the higher the material density, the lower the temperature at the same cross-section, the slower the cross-section temperature rise, while the smaller the moisture content has little effect on the cross-section temperature distribution.