Effects of Low Temperature and High Strain Rate on the Tensile Behaviors of High-Performance Energetic Composite

Zhe Jun Wang,Hong Fu Qiang,Zhao Jun Zhu,Guang Wang,M Jawaid,El-R Kenawy

doi:10.1051/matecconf/20166706013

Abstract

To further study the effects of low temperature and high strain rate on the tensile behaviors of hydroxyl-terminated polybutadiene (HTPB) propellant, an INSTRON testing machine was applied for carrying out the uniaxial tensile tests at low temperatures and room temperature after storage at low temperatures. The strain rates are in the range of 0.40 to 85.71 s −1 . Scanning electron microscope (SEM) was used for examining the failure mechanisms of HTPB propellant under the test conditions. The results reveal that HTPB propellant is still capable of large deformation at lower strain rates and low temperatures in the glass transition and glass state. The characteristics of stress-strain curves at room temperature after storage at low temperatures are the same with that directly obtained at room temperature. The effect of strain rate on the elastic modulus E at various temperatures is almost the same. However, the effect of strain rate on the maximum tensile stress σ m becomes weak with decreasing temperature. Furthermore, the strain e m is nearly independence of the strain rate at higher strain rates and the lowest test temperature in glass state. Continuously decreasing temperature can more easily cause the extensive brittle fracture of AP particles, even at lower strain rates. The temperature changes from room temperature to low temperature and then from low temperature to room temperature in a short time cannot influence the failure mechanism of HTPB propellant at room temperature and high strain rate.

Highlights

Solid propellant is the typical high-performance energetic composite and its mechanical properties and failure mechanisms are sensitive to strain rate and temperature [1]
hydroxyl-terminated polybutadiene (HTPB) propellant is still capable of large deformation at lower strain rates and low temperatures in the glass transition and glass state
The characteristics of stress-strain curves at room temperature after storage at low temperatures are the same with that directly obtained at room temperature (Figure 2(a)), which is different from that under quasi-static tensile tests in previous research [7]

Summary

Introduction

Solid propellant is the typical high-performance energetic composite and its mechanical properties and failure mechanisms are sensitive to strain rate and temperature [1]. The influence of components on the low temperature mechanical properties of solid propellants under quasi-static conditions had been investigated by Mohamed et al [5,6]. Further investigation is required to study the effects of low temperature and high strain rate on the tensile behaviors of HTPB propellant. Uniaxial high strain rate tensile tests at low temperatures and room temperature after storage at low temperatures were performed to further study the behaviors of HTPB propellant. Based on the test results, the effect of the different loading conditions on the mechanical properties and failure mechanisms of HTPB propellant was discussed. The correlation between the mechanical properties and failure mechanisms of HTPB propellant was analyzed

Material and Test Methods

Results and Discussion

Summary