Experimenal Study And Numerical Simulation On The Mechanics Characteristic Of Multi-Perforated Propellant

To evaluate and detect accurately mechanics characteristic of a new type multi-perforated propellant and assure safety design of the internal ballistics charge, the paper studies the stress-strain behavior of multi-perforated propellant grain using experimental study and numerical simulation. Main work are as follows:(1) The quasi-static compressive test on propellant grain was conducted by using universal material machine and experimental platform which was designed and assembled by myself. The results prove that the mechanical characteristic of propellant grain were greatly influenced by the temperature under quasi-statistic pressing. Characteristic of ideal elastic-plastic material to linear reinforced plastic behavior was presented at ordinary temperatures and characteristic of brittle materials was presented at low temperatures. The elasticity modulus and yield limit of propellant grain were higher and the poisson’s ratio and yield strain were lower at low temperatures. The mechanical parameters of propellant were less influenced by loading rate under quasi-statistic condition.(2) The dynamic impact test of propellant grain was conducted by using fatigue-testing machine and Split Hopkinson Pressure Bar. The results prove that viscoelasticity characteristic and power-law hardening on stress-strain curve were presented under dynamic impact at intermediate strain rate such as 5s-1 and high strain rate from355 s-1 to 1129 s-1 under dynamic impact process. Linear strain-hardening of stress-strain curve was presented on plastic deformation stage. The dynamic mechanical characteristics of propellant were greatly influenced by the strain rate. The bearing capacity, elasticity modulus and the maximum stress during the impacting were higher under the higher strain rate. The propellant grain was wispily ruptured when the strain rate reached 1129 s-1.(3) Numerical simulation of the quasi-static compressive process was done on propellant grain by using the software of finite element analysis (ANSYS). The results prove that the results of numerical simulation on propellant grain under quasi-static compressive process proved that the MISO model in ANSYS was suit to the mechanics characteristic of propellant grain under the situation of quasi-static contraction, and the results of simulation agreed well with the test results. The results of simulation prove that volumetric rupture mode was presented under the situation of quasi-static contraction on propellant grain.(4) Numerical simulation of the dynamic impact process was done on propellant grain by using the software of dynamic analysis(LS-DYNA). The results prove that the results of numerical simulation on propellant grain under dynamic impact process proved that the Piecewise Linear Plasticity model in LS-DYNA was suit to the mechanics characteristic of propellant grain under the situation of dynamic impact, and the results of simulation agreed well with the test results. The results of simulation prove that contact rupture mode was presented under the situation of high strain rate dynamic impact on propellant grain.