A Uniaxial Nonlinear Viscoelastic Constitutive Model With Damage for M30 Gun Propellant
Final rept. Sep 1991-Jul 1992
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
The nonlinear viscoelastic mechanical response of a conventional tank gun propellant, M30, is modeled using a modified superposition integral which incorporates the effects of microstructural fracture damage. Specifically, a linear, time-dependent kernel is convolved with the first-time derivative of a power-law function of stress and a damage softening function which accounts for damage evolution by a microcrack growth mechanism. The microcrack damage function is a master curve formed from shifted isothermal, compressive, uniaxial constant strain rate .01 1s to 420 1s data on solid, right-circular cylinders of M30 gun propellant. An attractive feature of the model is its ability to predict work-softening behavior under conditions of monotonically increasing deformation. Time-dependent predictions of stress versus time, failure stress versus failure time, and failure stress versus strain rate, quantitatively agree with experimental results from constant strain rate tests on the propellant. Theoretical predictions of time-dependent stresses for Heaviside and ballistic-like strain histories are also provided.... Constitutive modeling, M30 Gun propellant, Continuum damage mechanics, Nonlinear viscoelasticity, Uniaxial compression testing, Viscoelasticity, Continuum mechanics.
- Ammunition and Explosives