In recent years, the synthetic cores of sandwich panels have experienced an increase in demand to be replaced by environmentally friendly materials. Furthermore, with the stringent fire protocols introduced in the building codes due to recent fire incidents around the world, it is imperative to conduct fire performance studies for all structural materials. The mechanical performances of the different core structures in sandwich panels have been extensively studied and documented in the literature, although the influence of those core structures on the fire reaction properties has not yet been fully understood. The aim of this work is to experimentally investigate, for the first time, the effects of the core structures, namely, corrugated and honeycomb cores manufactured from flax reinforced polymeric composites and radiata pine plywood, on their flammability. A bench-scale cone calorimeter has been employed to measure the fire reaction properties of the two types of materials along with the subsequent effects of the core structures. The orientations of the cores were observed to significantly impact the performances of the samples under fire. The honeycomb cores, with the open cells exposed to the heat flux, generally had better fire performance compared to those of the corrugated cores with higher time to ignition (10 s or more) and time to peak heat release (65 s or more), having almost similar initial masses and peak heat release rates. Furthermore, among the two material systems, the plywood cores outperformed the flax-FRPP cores, specifically in ignition time, smoke production, total heat release and peak heat release rate. The results helped in confirming that the honeycomb cores have overall better fire performance and the use of plywood as the core material is viable even when fire is involved.

近年来，夹心板的合成芯已经经历了由环保材料代替的需求增加。此外，由于世界范围内最近发生的火灾事件，建筑法规中引入了严格的防火规程，因此必须对所有结构材料进行防火性能研究。尽管还没有完全了解夹芯板中不同芯结构的机械性能，但在文献中已对其进行了记录，尽管这些芯结构对着火反应性能的影响尚未得到充分认识。这项工作的目的是首次实验研究由亚麻增强聚合物复合材料和辐射松胶合板制成的瓦楞芯和蜂窝芯的结构，的易燃性。台式锥形量热仪已被用于测量两种材料的着火反应性能以及核心结构的后续影响。观察到芯的取向显着影响着火样品的性能。与开孔时间较长（10 s或更长）和峰值放热时间（65 s或更长）的瓦楞芯相比，蜂窝芯的开孔暴露于热流中，通常具有更好的防火性能，具有几乎相似的初始质量和峰值放热速率。此外，在两种材料系统中，胶合板芯的性能优于亚麻-FRPP芯，特别是在点火时间，烟雾产生，总热量释放和峰值热量释放率方面。