A temperature/strain-rate-dependent finite deformation constitutive and failure model for solid propellants

A constitutive model of solid propellants considering aging and confinement pressure

“…Overall, the predicted stressÀ strain curves are in good agreement with the experimental results, indicating that the developed model can accurately capture the effects of aging. It should be noted that the model framework is consistent with the 3D case [1] when combined with finite element methods and ultimate failure predictions [26]. As such, this model framework can be utilized in modeling the response of solid propellants under a range of loading conditions.…”

“…The initial linear stage is triggered by viscoelastic deformation [25]. It has been shown that the plateau phase of HTPB-APÀ Al solid propellants is caused by viscous flow and damage growth [26].…”

“…Consequently, the dilatation decreases, and the stress increases. The determination details of the damage-dependent parameters can be found in our previous works [1], and the parameters were chosen as the same as in the work [26]. After obtaining these parameters, we used the uniaxial tensile results of HTPB-APÀ Al solid propellants before aging to show the effectiveness of the model parameters, as shown in Figure 11 relaxation under a small strain of 0.03 can well predict the initial linear stage of the stress-strain curves.…”

“…Since the current experimental setup regulates the confined pressure within the confined tube, it is not feasible to measure volume dilatation directly. Therefore, there may be discrepancies between the predictions with and without confinement pressure [26]. In the future, a new experimental setup will be developed to precisely measure the volume dilatation during uniaxial tensile tests under confinement pressure.…”