Influence of prestrain on mechanical properties of highly-filled elastomers: Measurements and modeling

Abstract

The influence of prestrain on viscoelastic properties E Ã and tan d of four different HTPB composite propellants was measured using Dynamic Mechanical Analysis (DMA). Nonlinear behaviour in terms of prestrain was observed and then modelled using a modified generalized Maxwell model. Prestrain was introduced as a variable of the stiffness of each Maxwell element using simple two-parameter relationships. An algorithm was proposed and numerically implemented to identify the model parameters from the measurements. The performance of the identification method is discussed in terms of accuracy and robustness. The good match between the predictions and the experimental measurements shows that the dependence on the uniaxial prestrain of the complex modulus of the studied composite propellants can be described with few Maxwell elements but with good accuracy.

Prestrained biaxial DMA investigation of viscoelastic nonlinearities in highly filled elastomers

“…One can further remark that the model proposed here is different from the model developed in [9] or [10] where elements are added step by step in a Generalized Maxwell model, as a function of the increasing prestrain. The model here is described by the continuous spectrum H(t) with only one prestrain dependent parameter, and is not directly related to a Generalized Maxwell model [25].…”

“…Recently, an experimental exploration of the outcome of a uniaxial and biaxial prestrain on the viscoelastic properties of highly filled elastomers has been proposed (see [9] and [10]). …”

“…In [9], uniaxial experiments have been described using a simple phenomenological model. The model was able to represent the measured logarithmic evolution of the complex modulus using a generalized Maxwell model.…”

Microstructure and deformation mechanisms of a solid propellant using 1 H NMR spectroscopy

“…The relations between the nonlinear mechanical behavior at the macroscopic scale and the microstructure at the scale of the fillers or the polymer chains have been explored [1][2][3][4][5][6]. However, direct experimental evidence of the physical mechanisms of deformation at the scale of the polymer network is difficult to obtain.…”

Whisker-like sensors with tunable follicle sinus complex for underwater applications

“…However, for viscoelastic polymers this is not necessarily the case as both static (pre-strain) and dynamic loading conditions can have effects on bulk material properties. 20,21 In this analysis the relationship between both modulus of elasticity and viscosity and strain conditions is assumed to be piece-wise linear. The modulus E * F SC and viscosity µ * F SC of the membrane at a given strain state * are given by,…”