HTPB 推进剂细观损伤及载荷传递行为数值模拟

In order to study the micro-damage and transmission characteristics of hydroxyl-terminated polybutadiene(HTPB) propellant,a representative volume element(RVE)model of the propellant was established based on viscohyperelastic material constitutive and bilinear cohesive force models,combined with DIGIMAT.The load transfer and stress concentration between particles and matrix were quantitatively analyzed by stress concentration factor and load transfer coefficient.The research results show that the random position of particles did not have a significant effect on the mechanical properties,but the change of particle position due to dewetting may affect the crack propagation path.The greater the aspect ratio of the particle,the more obvious the stress concentration phenomenon,and circular particles are more likely to experience dewetting damage than elliptical particles.The higher the particle content,the greater the initial stage stress concentration of the particle;the smaller the stress concentration of the matrix,and the higher the efficiency of load transfer.The trend is reversed after dewetting,and the increase in the content of large particles will accelerate the process of interface damage and exacerbate the degree of interface damage.The larger the volume fraction of particles, the higher stress concentration factor of particles and matrix;the lower the efficiency of load transfer in the initial stage,the higher the efficiency of load transfer after dewetting.