Spall damage of a mild carbon steel: Effects of peak stress, strain rate and pulse duration

2016 ◽  
Vol 660 ◽  
pp. 139-147 ◽  
Author(s):  
C. Li ◽  
B. Li ◽  
J.Y. Huang ◽  
H.H. Ma ◽  
M.H. Zhu ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Strain Rate ◽  
Pulse Duration ◽  
Peak Stress ◽  
Stress Strain ◽  
Mild Carbon Steel ◽  
Spall Damage

AN EXPERIMENTAL STUDY ON THE IMPACT DEFORMATION AND THE STRAIN RATE SENSITIVITY IN SOME STRUCTURAL ADHESIVES

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5590-5595 ◽  
Author(s):  
TOSHIMASA NAGAI ◽  
TAKESHI IWAMOTO ◽  
TOSHIYUKI SAWA ◽  
YASUHISA SEKIGUCHI ◽  
HIDEAKI KURAMOTO ◽  
...  
Keyword(s):  
Strain Rate ◽  
Inelastic Deformation ◽  
Strain Softening ◽  
Peak Stress ◽  
Stress Strain ◽  
Structural Adhesives ◽  
Strain Behavior ◽  
Impact Deformation ◽  
The Impact ◽  
Softening Stage

The impact deformation behavior and the strain sensitivity of structural adhesives are experimentally investigated by using INSTRON-type universal testing machine and split Hopkinson pressure bar apparatus. The experimental results show some fundamental features of the typical compressive stress-strain behavior of polymers with linear elastic and nonlinear inelastic deformation stages. In the inelastic deformation, the peak stress, and the strain-softening stage after the peak can be observed at the entire range of strain-rate from 10-4 to 103 /s. In addition, it can be found that the relationship between the peak stress at the strain-softening stage and strain-rate for a semi-logarithm curve is linear in a range of low strain rate, however, that becomes nonlinear at high strain rate. Finally, some constitutive models try to be applied for to describe the stress-strain behavior of structural adhesives.

scholarly journals Uniaxial Dynamic Compressive Behaviors of Hydraulic Asphalt Concrete under the Coupling Effect between Temperature and Strain Rate

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5348
Author(s):  
Rui Tang ◽  
Zhenpeng Yu ◽  
Guoqing Liu ◽  
Furong Li ◽  
Wenbin Tang
Keyword(s):  
Quantitative Analysis ◽  
Strain Rate ◽  
Temperature Effect ◽  
Asphalt Concrete ◽  
Brittle Failure ◽  
Failure Modes ◽  
Strain Softening ◽  
Coupling Effect ◽  
Peak Stress ◽  
Stress Strain

To investigate the compressive dynamic properties of hydraulic asphalt concrete under various temperatures, four temperatures and four strain rates have been set to perform the uniaxial compression experiments using hydraulic servo machine in this paper. The influence of temperature and strain rate on the failure modes, stress-strain curves and mechanical characteristic parameters of hydraulic asphalt concrete is analyzed and the results reveal that the failure modes and stress-strain curves have significant temperature effect. When the temperature is between −20 °C and 0 °C, the failure mode is dominated by brittle failure of asphalt binder, and hydraulic asphalt concrete shows obvious strain softening. With the addition of temperature, the failure modes of specimens are transferred from brittle failure to ductile failure since the asphalt changes from elastic-brittleness to viscoelasticity. Influenced by temperature effect, the compressive stress-strain curves of hydraulic asphalt concrete show strain hardening while the peak stress of hydraulic asphalt concrete is obviously decreased, and the variation coefficient of peak stress has a power relation with temperature. With successive increases in strain rate, the stress-strain curves of hydraulic asphalt concrete gradually are transferred from strain hardening to strain softening. The peak stress and stiffness modulus of specimens under compression gradually increase, and the dynamic increase factor of peak stress is linearly related with the logarithm value of strain rate after dimensionless treatment. In terms of the quantitative analysis of the experimental data, two relationship models of the coupling effect between temperature and strain rate are proposed. The proposed models have good applicability to the quantitative analysis of the experimental results in the manuscript. This paper offers important insights into the application and development of hydraulic asphalt concrete in hydraulic engineering.

scholarly journals Hot Deformation Behavior and Constitutive Modeling of H13-Mod Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 846 ◽  
Author(s):  
Changmin Li ◽  
Yuan Liu ◽  
Yuanbiao Tan ◽  
Fei Zhao
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
High Strain ◽  
Flow Behavior ◽  
Peak Stress ◽  
Strain Rates ◽  
Hot Deformation Behavior ◽  
Stress Strain

The H13-mod steel optimized by composition and heat treatment has reached the performance index of the shield machine hob. The hot deformation behavior of the H13-mod steel was investigated by compression tests in the temperature range from 900 to 1150 °C and the strain rate range from 0.01 to 10 s−1. The true stress-strain curve showed that the rising stress at the beginning of deformation was mainly caused by work hardening. After the peak stress was attained, the curve drop and the flow softening phenomenon became more obvious at low strain rates. The flow behavior of the H13-mod steel was predicted by a strain-compensated Arrhenius-type constitutive equation. The relationship between the material constant in the Arrhenius-type constitutive equation and the true strain was established by a sixth-order polynomial. The correlation coefficient between the experimental value and the predicted value reached 0.987, which indicated that the constitutive equation can accurately estimate the flow stress during the deformation process. A good linear correlation was achieved between the peak stress (strain), critical stress (strain) and the Zener‒Hollomon parameters. The processing maps of the H13-mod steel under different strains were established. The instability region was mainly concentrated in the high-strain-rate region; however, the microstructure did not show any evidence of instability at high temperatures and high strain rates. Combined with the microstructure and electron backscattered diffraction (EBSD) test results under different deformations, the optimum hot working parameters were concluded to be 998–1026 °C and 0.01–0.02 s−1 and 1140–1150 °C and 0.01–0.057 s−1.

Effect of Strain Rate on Dynamic Recrystallization Behavior for V Micro-Alloy High-Carbon Steel

2012 ◽  
Vol 602-604 ◽  
pp. 401-404
Author(s):  
An Chao Ren ◽  
Yu Ji ◽  
Gui Feng Zhou ◽  
Ze Xi Yuan
Keyword(s):  
Carbon Steel ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
High Carbon Steel ◽  
Constant Strain Rate ◽  
Grain Morphology ◽  
Peak Stress ◽  
Compression Tests ◽  
High Carbon ◽  
Before And After

Isothermal constant strain rate compression tests on high-carbon steel are carried out under strain rate of 1s-1, 10s-1 and 50s-1 respectively and deformation of 0.7 using the THERMECMASTOR-Z thermal simulator at a temperature of 1000°C. The austenite grain morphology before and after deformation and the true stress-strain curves during the deformation process are analyzed. The experimental results show that increased strain rate can obviously contribute to the grain refinement, and when the strain rate is at low level (e.g. 1s-1)，increased strain rate can further help refine the grains. And under the same temperature conditions, as the deformation rate rises, peak stress will move toward the direction of strain increment，thus the dynamic recrystallization is not apt to occur.

Study on the Flow Stress Curve of the Warm Deformation of Medium Carbon Steel

2012 ◽  
Vol 535-537 ◽  
pp. 517-520 ◽  
Author(s):  
Zhi Jie Li ◽  
Yan Peng ◽  
Hong Min Liu ◽  
Li Zi Xiao ◽  
Su Fen Wang ◽  
...  
Keyword(s):  
Flow Stress ◽  
Carbon Steel ◽  
Strain Rate ◽  
Peak Stress ◽  
Medium Carbon Steel ◽  
Warm Deformation ◽  
Medium Carbon ◽  
Stress Curve ◽  
Flow Stress Curve ◽  
Gleeble 3500

The warm compression experiment of medium carbon steel was conducted using the Gleeble-3500 thermal/mechanical simulator system. By the experiment, the warm deformation of medium carbon steel was studied within the temperature (500~700°C) and the strain rate (0.001~10s-1). The results indicate that the flow stress was increasing with the lowering temperature and the higher strain rate. And the stress-strain curves could be divided into four parts, including four stage of the Strain-Hardening, the First Softening, the Strong Softening, and the Steady Deformation. Dynamic recovery softening has little effect on the flow stress. The peak stress was caused by kink and fracture of the lamellar cementite. Strong softening stage was longer than other one, while its softening influence was stronger compared with hot deformation.

Study on Constitutive Equation of 7085 Aluminum Alloy under High Deformation Temperature

2015 ◽  
Vol 1095 ◽  
pp. 579-582
Author(s):  
Rui Bin Mei ◽  
Bo Zhang ◽  
B. Cai ◽  
X.Y. Zhang ◽  
Z.T. Zou ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Temperature ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Peak Strain ◽  
Stress Strain ◽  
Deformation Velocity

The flow stress behavior of the 7085 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-10s-1. Dynamic recrystallization occurs in hot compression of 7085 alloy and the stress-strain curves are presented as wave with higher deformation temperature and strain rate. Increasing of deformation velocity and reducing temperature results in higher peak stress. Then a mathematical model has been developed to predict the stress-strain curves based on phenomenological representation of the curves and the traditional theories for constitutive equations which incorporate the power law. The constitutive equation expressed in terms of peak stress, peak strain and additional parameters to predict flow stress. The stress-strain curves of 7085 alloy predicted by this model are in good agreement with experimental results.

Compressive strength and creep behavior of hydrate-consolidated sand

1990 ◽  
Vol 27 (2) ◽  
pp. 255-258 ◽  
Author(s):  
I. Cameron ◽  
Y. P. Handa ◽  
T. H. W. Baker
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Creep Behavior ◽  
Gas Hydrates ◽  
Peak Stress ◽  
Strain Rates ◽  
Stress Strain ◽  
Frozen Sand ◽  
Cylindrical Samples

Cylindrical samples of sand consolidated with tetrahydrofuran hydrate were tested for their compressive strength and creep behavior under uniaxial compression. The samples were 15 cm in length and 7.5 cm in diameter and were tested at −10 °C. The results, when combined with our previous measurements on similar samples at −6 °C, show that the material becomes stronger by about 10% with decrease in temperature; otherwise, the slopes of the peak stress – strain rate curves are the same. These results are similar to those of sand consolidated with ice, except that in the latter case the increase in strength over the same temperature range is about 30%. Furthermore, the slope of the peak stress – strain rate curve for the hydrate-consolidated sand is almost zero, whereas for the ice-consolidated sand it is quite steep. Consequently, at strain rates below 10−5 s−1 the hydrate-consolidated sand is stronger, whereas at strain rates above 10−5 s−1 the ice-consolidated sand is the stronger material. Noticeable differences were also observed in the creep behavior of the hydrate- and ice-consolidated sands. At −10 °C, ice-consolidated sand failed in about 15 h under a stress of about 7 MPa, whereas hydrate-consolidated sand failed after 52.3 h under a stress of 12.2 MPa and some samples did not fail even after 540 h when subjected to a stress of 9.3 MPa. Key words: gas hydrates, ice, frozen sand, mechanical properties, compressive strength, creep behavior.

High strain rate and low temperature effects on the compressive behaviour of concrete

2020 ◽  
pp. 204141962092741
Author(s):  
Thomas J MacLean ◽  
Alan Lloyd
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
High Strain ◽  
Peak Stress ◽  
Image Correlation ◽  
Stress Strain ◽  
Compressive Behaviour ◽  
Average Strain Rate ◽  
Industrial Storage ◽  
Static Conditions

Temperature and strain rate are important factors when considering the mechanical properties of engineering materials, as they can greatly influence the material behaviour. The research presented here is an experimental investigation to determine the effects of low temperatures and high strain rates on the compressive behaviour of concrete. The primary purpose of the research is the development of experimental stress–strain relationships under these conditions, as this is a largely unexplored research topic. Thirty-five 101.6 mm × 203.2 mm concrete cylinders were tested in uniaxial compression at the University of New Brunswick. The specimens were loaded either under static conditions or dynamically with an average strain rate of approximately 1 s−1, while being exposed to temperatures from 20°C to −70°C to simulate extreme climatic temperature and those attainable within industrial storage facilities. The compression strain of the specimens was obtained using digital image correlation. The mechanical properties studied were the compressive strength, strain associated with the peak stress and general stress–strain behaviour due to the increased strain rate and temperature variations.

Study of Hot Deformation Behavior of 6082 Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 340-346 ◽  
Author(s):  
Peng Long Wang ◽  
Hai Tao Jiang ◽  
Rui Jie Zhang ◽  
Shi Yao Huang
Keyword(s):  
Aluminum Alloy ◽  
Strain Rate ◽  
Work Hardening ◽  
Hot Deformation ◽  
Processing Map ◽  
Peak Stress ◽  
True Stress ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
6082 Aluminum Alloy

A set of hot deformation experiments 6082 aluminum alloy were carried out on the Gleeble-3500 thermal simulation machine. The true stress-strain curves were obtained in the condition of temperatures 425 ̊C,450 ̊C,475 ̊C and 500 ̊C, strain rate 0.01s-1, 0.1s-1, 1s-1 and 10s-1. At the low strain rate (0.01s-1, 0.1s-1), true stress-strain curves exhibited typical work hardening and flow softening features, but at the high strain rate (1s-1, 10s-1), true stress-strain curves just exhibited typical work hardening. The peak stress of current alloy decreased with temperature and increased with strain rate, which can be represented by a hyperbolic sine equation using the Zener-Hollomon parameter (Z). The processing map was calculated and analyzed according to dynamic materials mode (DMM). The processing map showed the reasonable hot working region of 6082 aluminum ally.

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