炭化层是绝热材料烧蚀过程中物理、化学和力学相互耦合作用的桥梁和纽带,其结构和力学性能的表征是绝热材料烧蚀预示数值计算的关键因素。文中针对三元乙丙绝热材料炭化层结构进行了分析,并基于炭化层多孔介质特性,利用固体多孔介质理论建立了炭化层关于孔隙率为参数的力学表征模型;根据炭化层强度测定结果,确定炭化层强度表征系数,建立炭化层破坏准则,从而为绝热材料烧蚀预示数值计算提供炭化层力学性能参数。

The coupling effect of physics, chemistry and mechanics is through charring layer in the process of ablation of the insulation material. Description of the structure and mechanical properties of charring layer are the critical factor to numerical computation for foretelling the ablation of insulation material. The characteristics of charring layer structure of EPDM insulation under sorts of ablating conditions were analyzed, and based on characteristic of porous medium of charring layer, the mechanical model with porosity as parameter was modeled by using theory of solid porous medium. According to the intensity determination of charring layer, the coefficient of intensity model was determined, then, the failure criterion of charring layer was set up, which can provide mechanical parameters of charring layer for numerical computation to foretell the ablation of insulation material.