scholarly journals Compressive mechanical properties of HTPB propellant at low temperatures and high strain rates

2017 ◽  
Vol 7 ◽  
pp. 4079-4084 ◽  
Author(s):  
Xiangdong Chen ◽  
Jianwei Lai ◽  
Xin-long Chang ◽  
Youhong Zhang ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Htpb Propellant

A method for determining the main mechanical properties of soft soils at high strain rates (103–105 s−1) and load amplitudes up to several gigapascals

2005 ◽  
Vol 31 (6) ◽  
pp. 530-531 ◽  
Author(s):  
A. M. Bragov ◽  
A. K. Lomunov ◽  
I. V. Sergeichev ◽  
W. Proud ◽  
K. Tsembelis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Soft Soils

INVESTIGATING THE INFLUENCE OF ENVIRONMENTAL CONDITIONING ON EPOXY RESINS AT QUASISTATIC AND HIGH STRAIN RATES FOR MATERIAL OPERATING LIMIT

2021 ◽  
Author(s):  
SAGAR M. DOSHI, SAGAR M. DOSHI, ◽  
NITHINKUMAR MANOHARAN ◽  
BAZLE Z. (GAMA) HAQUE, ◽  
JOSEPH DEITZEL ◽  
JOHN W. GILLESPIE, JR.
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Yield Stress ◽  
High Strain ◽  
Operating Conditions ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Wide Range ◽  
Environmental Aging

Epoxy resin-based composite panels used for armors may be subjected to a wide range of operating temperatures (-55°C to 76°C) and high strain rates on the order of 103-104 s-1. Over the life cycle, various environmental factors also affect the resin properties and hence influence the performance of the composites. Therefore, it is critical to determine the stress-strain behavior of the epoxy resin over a wide range of strain rates and temperatures for accurate multi-scale modeling of composites and to investigate the influence of environmental aging on the resin properties. Additionally, the characterization of key mechanical properties such as yield stress, modulus, and energy absorption (i.e. area under the stress-strain curve) at varying temperatures and moisture can provide critical data to calculate the material operating limits. In this study, we characterize mechanical properties of neat epoxy resin, SC-15 (currently used in structural armor) and RDL-RDC using uniaxial compression testing. RDL-RDC, developed by Huntsman Corporation, has a glass transition temperature of ~ 120°C, compared to ~ 85°C of SC-15. A split Hopkinson pressure bar is used for high strain rate testing. Quasistatic testing is conducted using a screw-driven testing machine (Instron 4484) at 10-3 s-1 and 10-1 s-1 strain rates and varying temperatures. The yield stress is fit to a modified Eyring model over the varying strain rates at room temperature. For rapid investigation of resistance to environmental aging, accelerated aging tests are conducted by immersing the specimens in 100°C water for 48 hours. Specimens are conditioned in an environmental chamber at 76 °C and 88% RH until they reach equilibrium. Tests are then conducted at five different temperatures from 0°C to 95°C, and key mechanical properties are then plotted vs. temperature. The results presented are an important step towards developing a methodology to identify environmental operating conditions for composite ground vehicle applications.

Microstructural and Dynamic Mechanical Characterization of Biodegradable Magnesium-Calcium Alloy for Orthopedic Implants

2014 ◽  
Author(s):  
V. S. Brooks ◽  
Y. B. Guo
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Orthopedic Implants ◽  
Strain Rates ◽  
High Strain Rates ◽  
Static Compression ◽  
Metallic Biomaterial

Magnesium-Calcium (Mg-Ca) alloy is an emerging metallic biomaterial for manufacturing biodegradable orthopedic implants. However, very few studies have been conducted on mechanical properties of the bi-phase Mg-Ca alloy, especially at the high strain rates often encountered in manufacturing processes. The mechanical properties are critical to design and manufacturing of Mg-Ca implants. The objective of this study is to study the microstructural and mechanical properties of Mg-Ca0.8 (wt %) alloy. Both elastic and plastic behaviors of the Mg-Ca0.8 alloy were characterized at different strains and strain rates in quasi-static tension and compression testing as well as dynamic split-Hopkinson pressure bar (SHPB) testing. It has been shown that Young’s modulus of Mg-Ca0.8 alloy in quasi-static compression is much higher than those at high strain rates. Yield strength and ultimate strength of the material are very sensitive to strain rates and increase with strain rate in compression. Strain softening also occurs at large strains in dynamic compression. Furthermore, quasi-static mechanical behavior of the material in tension is very different from that in compression. The stress-strain data was repeatable with reasonable accuracy in both deformation modes. In addition, a set of material constants for the internal state variable plasticity model has been obtained to model the dynamical mechanical behavior of the novel metallic biomaterial.

Fracture of Laminated and In Situ Niobium Silicide-Niobium Composites

1996 ◽  
Vol 434 ◽  
Author(s):  
J. D. Rigney
Keyword(s):  
Low Temperatures ◽  
Fracture Resistance ◽  
Fracture Behavior ◽  
High Strain ◽  
Theoretical Models ◽  
High Yield ◽  
Strain Rates ◽  
High Strain Rates ◽  
Ductile Phase

AbstractThe mechanisms contributing to the fracture resistance of refractory metal intermetallic composites containing a BCC metallic phase (niobium) were investigated using model Nb-Si laminates and in situ composites. The controlling influence of ductile phase yield strength and fracture behavior were investigated by varying laminate processing parameters, and/or altering temperatures and applied strain rates during fracture experiments on all materials. The fracture behavior of “ductile” constituents were found to be influenced by phase grain size, solid solution content, constraint (as influenced by interfacial bond strengths), and the testing condition (high strain rates and low temperatures). The measured fracture resistance, when compared to theoretical models, was shown to be controlled by the “toughness” of the “ductile” phase and independent of the fracture behavior promoted (cleavage and ductile). The loss in ductility due to cleavage by high constraint, high strain rates and/or low temperatures was compensated by high yield and cleavage fracture stresses in order to provide a level of toughening similar to that contributed by ligaments which failed with lower yield stresses and greater strains.

Study of mechanical properties of aluminum, AMg6M alloy, and polymethyl methacrylate at high strain rates under the action of picosecond laser radiation

2012 ◽  
Vol 57 (2) ◽  
pp. 64-66 ◽  
Author(s):  
S. A. Abrosimov ◽  
A. P. Bazhulin ◽  
V. V. Voronov ◽  
I. K. Krasyuk ◽  
P. P. Pashinin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Radiation ◽  
Polymethyl Methacrylate ◽  
High Strain ◽  
Picosecond Laser ◽  
Strain Rates ◽  
High Strain Rates

Dynamic mechanical properties of whisker/PA66 composites at high strain rates

Polymer ◽  
2005 ◽  
Vol 46 (10) ◽  
pp. 3528-3534 ◽  
Author(s):  
Xiangyang Hao ◽  
Guosheng Gai ◽  
Fangyun Lu ◽  
Xijin Zhao ◽  
Yihe Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strain ◽  
Dynamic Mechanical Properties ◽  
Strain Rates ◽  
High Strain Rates ◽  
Dynamic Mechanical
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