Detailed simulations of propellant slumping in the titanIV SRMU PQM-1

We utilize our tightly-coupled fluid/structure/combustion solid propellent rocket simulation package ("Rocstar") to study the unexpectedly large deformation of propellant at the center joint slot in a prequalification version of the Titan IV SRMU booster, which exploded on the test stand En 1991. We describe and demonstrate recent enhancements to our mesh modification scheme, which enable Rocstar to handle very large geometrical changes. With the use of rigorous composite-material homogenization theory, we describe a macroscopic constitutive model that accounts for continuous void nucleation and growth upon straining. This model is calibrated using stress-strain curves derived from uniaxial tension experiments. We present preliminary results from Titan simulations employing these new capabilities.