橡胶最大主伸长率对堵盖开裂性能影响研究

Effect of maximum principal elongation of rubber material on cracking performance of nozzle closure

针对某型号固体火箭发动机用橡胶堵盖承压状态下开裂的问题,基于开裂能密度对于橡胶材料的开裂机理及准静态拉伸载荷下的力学行为开展研究,得出橡胶材料的开裂性能主要与材料的最大主伸长率有关,且橡胶材料在准静态拉伸载荷作用下主要呈现超弹性,在150%应变范围内,Ogden超弹性本构模型可以较好地表征其力学行为;基于Abaqus有限元软件及承压试验对不同最大主伸长率橡胶材料承压状态下橡胶堵盖的应力场分布规律展开研究,得出其最大应力区域为内型面根部,且橡胶材料的最大主伸长率提高13%,最大应力降低4.5%,当最大主伸长率提高94%,其最大应力降低约29%,即相同工况下,橡胶材料最大主伸长率越高,堵盖中最大应力越小,因此通过调整橡胶材料的最大主伸长率可以有效地降低橡胶堵盖结构的开裂风险。

Aiming at the problem of cracking of a certain Type of rubber nozzle closure under pressure,based on the cracking energy density,the cracking mechanism of rubber materials and the mechanical behavior under quasi-static tensile load were studied,and it was consluded that the cracking energy density of rubber materials is mainly related to the maximum principle elongation of the material,and the rubber material is mainly hyperelastic under quasi-static tensile load,in the 150%strain range,the Ogden hyperelastic constitutive model can fit its mechanical behavior well;Based on the Abaqus finite element software and pressure-bear test,the distribution law of the stress distribution of nozzle closure in different maximum main elongation rubber materials is carried out,and the maximum stess mainly distribute in the root of the inner surface,moreover,when the maximum main elongation of the rubber material increase 13%,the maximum stress reduce 4.5%,when the maximum main elongation of the rubber material increase 94%,the maximum stress reduce 29%,that is,under the same conditions,the larger the maximum principal elongation of rubber material is,the smaller the maximum stress of the nozzle closure is,so the risk of cracking of nozzle closure structure can be effectively reduced by adjusting the maximum main elongation of the rubber material.