Effect of Pre‐strain Aging on the Damage Properties of Composite Solid Propellants based on a Constitutive Equation

Liu

Propellants Explo Pyrotec

et al. 2022

Self Cite

To study the tensile properties of GAP/CL-20/HMX (GCH) propellant, a new generation high energy solid propellant, uniaxial tensile test and dynamic mechanical analysis (DMA) test were performed at different temperatures (233.15-333.15 K) and strain rates (0.000476-0.9524 s À 1 ). The experimental results show that, unlike Hydroxyl-terminated Polybutadiene (HTPB) and Nitrate Ester Plasticized Polyether (NEPE) propellants, GCH propellant have special arc section in the initial tensile stage at room temperature and high temperature. This phenomenon may be caused by the stretching of the curled molecular chains. The variation of mechanical properties shows that the maximum tensile strength and initial elastic modulus increase with the decrease of temperature and the increase of strain rate. The variation of maximum elongation is complex, which increases with the increase of strain rate at room temperature and high temperature, and first increases then decreases with the increase of strain at low temperature. The constitutive model of the GCH propellant was established by introducing the chain extension and the debonding damage thresholds. Both of which show a linear double logarithmic increasing trend with the increase of strain rate at room and high temperature. The latter shows a linear double logarithmic decrease trend with the increase of strain rate at the low temperature.

Section: Resultsmentioning

confidence: 99%

Section: Constitutive Model Theorymentioning

confidence: 99%

Study on Tensile Mechanical Properties of GAP/CL‐20/HMX Propellant

Liu

Propellants Explo Pyrotec

et al. 2022

Self Cite

“…The related parameters of the maximum tensile strength ( σ m ), initial modulus ( E 0 ), elongation at maximum tensile strength ( ε m ), and elongation at break ( ε b ) were calculated by the stress–strain curves. 24 …”

Section: Methodsmentioning

confidence: 99%

Synthesis of two novel neutral polymeric bonding agents to enhance the mechanical properties of composite solid propellants

Xu³

et al. 2022

RSC Adv.

Propellants Explo Pyrotec

“…Based on statistical theory, the Weibull probability distribution function [48] can be used to characterize the local failure strength of these materials [49–52]. Assuming that damage evolution is dependent on the tensile strain and damage strain threshold, the damage probability density function of microelements can be expressed as follows:…”

Section: Constitutive Modelmentioning

confidence: 99%

Experimental Investigation and Modeling the Compressive Behavior of NEPE Propellant under Confining Pressure

Chen

Hou

et al. 2021

In order to study the effects of confining pressure and strain rate on the mechanical properties of the Nitrate Ester Plasticized Polyether (NEPE) propellant, compressive tests were conducted under various confining pressure conditions and strain rates using a new‐designed active gas confining pressure testing machine. The stress‐strain curves and mechanical properties of the NEPE propellant under varying confining pressure conditions and strain rates were obtained. The results show that the compressive mechanical properties of the NEPE propellant are remarkably influenced by the confining pressure and strain rate. The compressive strength under confining pressure is obviously larger than those without applied confining pressure. With the coupled effects of the confining pressure and strain rate, the compressive strength under 5.4 MPa and 6.67×10−2 s−1 is 2.17 times of its value at room condition and 6.67×10−4 s−1. Then, based on previous tensile results, the quantified comparisons of tensile and compressive mechanical properties under different experimental conditions were presented. Finally, a nonlinear constitutive model with damage was constructed to model the effect of pressure. The statistical damage model parameters were defined as ExpDec1 function of pressure P. The calibrated model can accurately predict the mechanical behaviour of the NEPE propellant under different confining pressure conditions and strain rates.