Micromechanics equivalent modeling method for composite solid propellant

The invention discloses a composite solid propellant mesomechanics equivalent modeling method, and belongs to the technical field of spaceflight. The method specifically comprises the following steps: firstly, dividing oxidant particles in an actual formula of the composite solid propellant into small particles and large particles; then, in combination with a molecular dynamics method, inputting particle sizes and volume fractions of small particles, and establishing an equivalent matrix model; through finite element simulation calculation, fixed strain is loaded at the two ends of the model, and a stress relaxation curve of the equivalent matrix model is output. Similarly, inputting the particle size and the volume fraction of the large particles, taking the stress relaxation curve as a material parameter of an equivalent matrix material, and establishing an equivalent mesoscopic model as a physical model; and finally, calculating the macro-performance of the physical model in combination with commercial num