NUMERICAL STUDY OF STRUCTURES OF LAMINAR OPPOSED FLOW PREMIXED METHANE-HYDROGEN-AIR FLAMES AT LOW STRAIN RATE

2011 ◽  
Vol 3 (5) ◽  
pp. 359-373
Author(s):  
Deshpande Shrikrishna ◽  
R. Sreenivasan ◽  
Vasudevan Raghavan
Keyword(s):  
Strain Rate ◽  
Numerical Study ◽  
Opposed Flow ◽  
Low Strain Rate

MECHANICAL CHARACTERIZATION OF POLYMER MATERIALS UNDER LOW STRAIN RATE LOADING

2017 ◽  
Vol 5 (3) ◽  
pp. 8
Author(s):  
KUMAR DINESH ◽  
KAUR ARSHDEEP ◽  
AGGARWAL YUGAM KUMAR ◽  
UNIYAL PIYUSH ◽  
KUMAR NAVIN ◽  
...  
Keyword(s):  
Strain Rate ◽  
Mechanical Characterization ◽  
Polymer Materials ◽  
Strain Rate Loading ◽  
Low Strain Rate

scholarly journals Microstructure evolution of TC4 powder by spark plasma sintering after hot deformation

2020 ◽  
Vol 39 (1) ◽  
pp. 457-465
Author(s):  
Jiangpeng Yan ◽  
Zhimin Zhang ◽  
Jian Xu ◽  
Yaojin Wu ◽  
Xi Zhao ◽  
...  
Keyword(s):  
Strain Rate ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Hot Deformation ◽  
Tc4 Titanium Alloy ◽  
Weave Structure ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Average Relative Density ◽  
Low Strain Rate

AbstractThe cylindrical samples of TC4 titanium alloy prepared by spark plasma sintering (SPS) were compressed with hot deformation of 70% on the thermosimulation machine of Gleeble-1500. The temperature of the processes ranged from 850°C to 1,050°C, and the strain rates varied between 0.001 and 5 s−1. The relative density of the sintered and compressed samples was measured by the Archimedes principle. During hot deformation, the microstructure of the sample was observed. The results show that the average relative density of the samples was 90.2% after SPS. And the relative density was about 98% after the hot deformation of 70%. Under high temperature (>950°C), the sensitivity of flow stress to temperature was reduced. At low strain rate (0.001 s−1), the increase in the deformation temperature promoted the growth of dynamic recrystallization (DRX). At the same temperature, the increase in strain rate slowed down the growth of DRX grains. And the variation tendency was shown from the basket-weave structure to the Widmanstätten structure at a low strain rate (<0.1 s−1), with increase in the strain rate.

Evaluation of threshold stress intensity in high strength hydrogen charged steel in low strain rate tension tests

1993 ◽  
Vol 9 (11) ◽  
pp. 1009-1013 ◽  
Author(s):  
B. Ule ◽  
F. Vodopivec ◽  
L. Vehovar ◽  
J. Žvokelj ◽  
L. Kosec
Keyword(s):  
Stress Intensity ◽  
Strain Rate ◽  
Threshold Stress ◽  
High Strength ◽  
Threshold Stress Intensity ◽  
Tension Tests ◽  
Low Strain Rate

Looking for the hidden morphological signature of active faults in a Low Strain Rate region: clues from the eastern Kachchh region (NW India) 

2021 ◽  
Author(s):  
Eshaan Srivastava ◽  
Nicolò Parrino ◽  
Javed Malik ◽  
Fabrizio Pepe ◽  
Pierfrancesco Burrato
Keyword(s):  
Strain Rate ◽  
Multidisciplinary Approach ◽  
Surface Deformation ◽  
Active Faults ◽  
Tectonic Geomorphology ◽  
Seismic Events ◽  
Rate Region ◽  
Ongoing Work ◽  
Morphotectonic Evolution ◽  
Low Strain Rate

&lt;p&gt;The Kachchh region (NW India), a pericratonic rift basin delimited by E-W trending major thrust faults, is a Low Strain Rate region[PB1]&amp;#160;. In this area, the tectonic forcing magnitude is stronger enough to trigger infrequent significant earthquakes but not enough to overprint the climatic forcing signature. As a consequence, the active faults sources of the largest seismic events are largely poorly known and their geomorphic signature is subdued.&amp;#160;&lt;/p&gt;&lt;p&gt;Instrumental and paleoseismological evidence highlights that the eastern part of Kachchh experienced a significant number of seismic events such as the 1819-06-16 Allah Bund earthquake (Mw 7.8, also known as the Rann of Kutch earthquake), the 1956-07-21 Anjar earthquake (Mw 6.1), the 2001-01-26 Bhuj earthquake (Mw 7.6) and the 2006 events (Mw 5.0 and 5.6 earthquake occurred along Island Belt Fault and Gedi fault).&amp;#160;&lt;/p&gt;&lt;p&gt;In this region, the unavailability of useful outcrop information due to a significant climatic overprinting of the fault&amp;#8217;s morphological signatures hampers the detection and parametrization of actively deforming faults.&lt;/p&gt;&lt;p&gt;For this reason, in this ongoing work, we propose a multidisciplinary approach, aimed at detecting active geological structures and their related [PB2]&amp;#160;surface deformation, which mainly consists of quantitative tectonic geomorphology and paleoseismological analyses and structural interpretation and modelling. Preliminary results are a morphotectonic evolution model and 3D fault model of the study area. Finally, we stress the concept that only a multidisciplinary approach could provide useful information to understand better the highly debated active tectonic framework of the study area.&lt;/p&gt;

scholarly journals Effects of strain rate and CO2 on no formation in CH4/N2/O2 counter-flow diffusion flames

2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 769-776
Author(s):  
Fei Ren ◽  
Longkai Xiang ◽  
Huaqiang Chu ◽  
Weiwei Han
Keyword(s):  
Strain Rate ◽  
Diffusion Flames ◽  
Numerical Study ◽  
Flame Temperature ◽  
Co2 Concentration ◽  
No Production ◽  
Counter Flow ◽  
Detailed Chemistry ◽  
No Formation ◽  
Key Factor

The reduction of nitrogen oxides in the high temperature flame is the key factor affecting the oxygen-enriched combustion performance. A numerical study using an OPPDIF code with detailed chemistry mechanism GRI 3.0 was carried out to focus on the effect of strain rate (25-130 s?1) and CO2 addition (0-0.59) on the oxidizer side on NO emission in CH4 / N2 / O2 counter-flow diffusion flame. The mole fraction profiles of flame structures, NO, NO2 and some selected radicals (H, O, OH) and the sensitivity of the dominant reactions contributing to NO formation in the counter-flow diffusion flames of CH4\/ N2 /O2 and CH4 / N2 / O2 / CO2 were obtained. The results indicated that the flame temperature and the amount of NO were reduced while the sensitivity of reactions to the prompt NO formation was gradually increased with the increasing strain rate. Furthermore, it is shown that with the increasing CO2 concentration in oxidizer, CO2 was directly involved in the reaction of NO consumption. The flame temperature and NO production were decreased dramatically and the mechanism of NO production was transformed from the thermal to prompt route.

Experimental and Numerical Study of Soft Tissue Surrogate Behavior Under Ballistic Loading

2012 ◽  
Author(s):  
Ericka K. Amborn ◽  
Karim H. Muci-Küchler ◽  
Brandon J. Hinz
Keyword(s):  
Soft Tissue ◽  
Constitutive Model ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
Constitutive Models ◽  
Material Behavior ◽  
Good Representation

Studying the high strain rate behavior of soft tissues and soft tissue surrogates is of interest to improve the understanding of injury mechanisms during blast and impact events. Tests such as the split Hopkinson pressure bar have been successfully used to characterize material behavior at high strain rates under simple loading conditions. However, experiments involving more complex stress states are needed for the validation of constitutive models and numerical simulation techniques for fast transient events. In particular, for the case of ballistic injuries, controlled tests that can better reflect the effects induced by a penetrating projectile are of interest. This paper presents an experiment that tries to achieve that goal. The experimental setup involves a cylindrical test sample made of a translucent soft tissue surrogate that has a small pre-made cylindrical channel along its axis. A small caliber projectile is fired through the pre-made channel at representative speeds using an air rifle. High speed video is used in conjunction with specialized software to generate data for model validation. A Lagrangian Finite Element Method (FEM) model was prepared in ABAQUS/Explicit to simulate the experiments. Different hyperelastic constitutive models were explored to represent the behavior of the soft tissue surrogate and the required material properties were obtained from high strain rate test data reported in the open literature. The simulation results corresponding to each constitutive model considered were qualitatively compared against the experimental data for a single projectile speed. The constitutive model that provided the closest match was then used to perform an additional simulation at a different projectile velocity and quantitative comparisons between numerical and experimental results were made. The comparisons showed that the Marlow hyperelastic model available in ABAQUS/Explicit was able to produce a good representation of the soft tissue surrogate behavior observed experimentally at the two projectile speeds considered.

Numerical study on the mechanical behavior of a polyurethane adhesive under high strain rate

2019 ◽  
Vol 158 ◽  
pp. 131-140 ◽  
Author(s):  
Zhemin Jia ◽  
Guoqing Yuan ◽  
Xiaoping Feng ◽  
Yun Zou
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
High Strain ◽  
Numerical Study ◽  
Polyurethane Adhesive
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