Research on Mechanical Model of EPDM Insulation Charring Layer

Abstract

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 is the critical factor to numerical computation for foretelling the ablation of insulation material. The characteristic of charring layer structure of EPDM insulation at sorts of ablating condition 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 the mechanical parameters of charring layer for numerical computation to foretell the ablation of insulation material.

Performance of EPDM Composites Under Thermal Plasma Ablative Tests

“…Ethylene propylene diene monomer (EPDM) composite is a type of carbonized ablation material; its low density, high elongation, and good ablation resistance have led to its wide application as internal insulation in solid rocket motors (SRMs) [1][2][3] . Additionally, EPDM possesses the lowest density among elastomers (0.85 g/cm 3 ); this is an essential property; for these reasons, EPDM is the ideal candidate matrix for elastomeric ablatives [4][5][6] . EPDM rubber is a non-crystalline reinforcement rubber showing low mechanical strength, making it necessary to use reinforcement agents such as silica to improve its mechanical properties 4,[7][8][9][10] .…”