燃烧条件下格构增强泡桐木夹芯板热传导模型

Heat Conduction Model of Unidirectional Lattice Reinforced Sandwich Panels Exposed to Fire

以单向格构增强泡桐木夹芯板为火灾试验的研究对象,建立了夹芯板的一维热传导模型,并用有限差分法计算了夹芯板的温度梯度;同时,通过夹芯板火灾试验进行了模型验证.结果表明:夹芯板在不同时间段内沿厚度方向存在明显的温度梯度;夹芯板在承受60 min的火灾或者高温时,其受热面板与芯材均发生了不同程度的热分解,材料炭化并形成炭化层,阻止了热量传导;夹芯板中性轴以上部分的变化较小,性能稳定,具有一定承载能力.另外,通过分析受热过程中芯材与格构的温度变化,验证了芯材对格构性能的影响.

The unidirectional lattice reinforced paulownia wood sandwich board was studied in the fire test,and its one-dimensional heat conduction model was established.The finite difference method was used to compare the calculated results of the heat conduction model with the experimental results.It shows that the two results are in good agreement.According to the fire test and finite element simulation of sandwich panels,it is found that the sandwich plate has obvious temperature gradient along the thickness direction in different time periods.When the exposure time is larger than 60 min,the heat decomposition of skins and core materials occurs,meanwhile the heat transfer is blocked due to the charring effects.Moreover,the influence of core material on lattice performance is verified by analyzing the temperature change of core material and lattice structure during heating process.