Determination of stress-strain characteristics at very high strain rates

1970 ◽  
Vol 10 (9) ◽  
pp. 370-376 ◽  
Author(s):  
C. K. H. Dharan ◽  
F. E. Hauser
Keyword(s):  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Very High

scholarly journals Modelling and simulation of dynamic recrystallization (DRX) in OFHC copper at very high strain rates

2017 ◽  
Author(s):  
G. Testa ◽  
N. Bonora ◽  
A. Ruggiero ◽  
G. Iannitti ◽  
I. Persechino ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Strain ◽  
Modelling And Simulation ◽  
Ofhc Copper ◽  
Strain Rates ◽  
High Strain Rates ◽  
Very High

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.

Identification of constitutive equations at very high strain rates using shock wave produced by laser

2021 ◽  
pp. 104432
Author(s):  
R. Seddik ◽  
A. Rondepierre ◽  
S. Prabhakaran ◽  
L. Morin ◽  
V. Favier ◽  
...  
Keyword(s):  
Shock Wave ◽  
Constitutive Equations ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Very High

A Dynamic Mechanical Analysis of T2 Copper at High Strain Rates

2019 ◽  
Vol 812 ◽  
pp. 38-44
Author(s):  
Shuai Chen ◽  
Wen Bin Li ◽  
Xiao Ming Wang ◽  
Wen Jin Yao
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Pure Copper ◽  
Dislocation Slip ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Shpb Test

This work compares the pure copper (T2 copper)’s stress-strain relationship at different strain rates in the uni-axial tension test and Split Hopkinson Pressure Bar (SHPB) test. Small samples were utilized in the high strain rate SHPB test in which the accuracy was modified by numerical simulation. The experimental results showed that the T2 copper’s yield strength at high strain rates largely outweighed the quasi static yield strength. The flow stress in the stress-strain curves at different strain rates appeared to be divergent and increased with the increase in strain rates, showing great strain strengthening and strain rate hardening effects. Metallographic observation showed that the microstructure of T2 copper changed from equiaxed grains to twins and the interaction between the dislocation slip zone grain boundary and twins promoted the super plasticity distortion in T2 copper.

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