Research of Impetus Tendentiousness in Yuncheng Mine 3# Coal Seam

2015 ◽  
Vol 723 ◽  
pp. 313-316
Author(s):  
Han Jun Wang ◽  
Lie Li ◽  
Tian Yu He ◽  
Yan Qiu Zhang ◽  
Tao Tao Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Coal Seam ◽  
Impact Energy ◽  
Country Rock ◽  
National Standards ◽  
Strong Impact ◽  
Class Iii ◽  
Laboratory Determination ◽  
The Impact

The depth of Yuncheng 3# coal seam is 600m, the country rock appear softening and weakening. Evaluate the impetus tendentiousness strength of the mine 3# coal seam through the 3# coal sampling on-site and laboratory indicators of the impact energy coal experimental study. The laboratory determination shows the impetus tendentiousness of Yuncheng Mine 3# coal seam belongs to class III which has strong impact tendentious based on national standards.

scholarly journals Probing the Impact Energy Release Behavior of Al/Ni-Based Reactive Metals with Experimental and Numerical Methods

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 499 ◽  
Author(s):  
Kerong Ren ◽  
Rong Chen ◽  
Yuliang Lin ◽  
Shun Li ◽  
Xianfeng Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Constitutive Model ◽  
Energy Release ◽  
Chemical Reaction ◽  
Impact Energy ◽  
Testing Machine ◽  
Strong Impact ◽  
Release Behavior ◽  
The Impact ◽  
Reactive Metals

Reactive metals (RMs) are a new class of material that can withstand mechanical loads and chemically react to release large amounts of heat under strong impact loading. They are gradually becoming widely used in defense and military fields, including for high-efficiency warheads and reactive armor. For the numerical simulation method considering the combined mechanical-thermo-chemical process for the impact energy release behavior of the RMs, the Al/Ni-based RMs were investigated in this work by combining experiments, theoretical calculations and a numerical simulation. Three kinds of Al/Ni-based RMs (Al-Ni, Al-Ni-CuO and Al-Ni-MoO3), were prepared using the hot-pressing forming process. Firstly, the compressive behavior and the parameters of the Johnson-Cook constitutive model were obtained using a mechanical testing machine and split Hopkinson pressure bars (SHPB). Secondly, the parameters of the equation of state (EOS) under the medium and low pressure conditions of the Al/Ni-based RMs, which were was seen as porous mixtures with high theoretical material density percentages (TMD%), were calculated based on the cold-energy superposition theory and the Wu-Jing method. Third, the impact energy release behaviors of the three RMs were studied with direct ballistic tests. The shock temperatures at different impact velocities were calculated based on the existing shock-induced chemical reaction thermo-chemical model while considering the chemical reaction efficiency, the relationship between the shock temperature and the extent of the chemical reaction was established, and the parameters of the relevant chemical kinetic equations were fitted. Finally, the user’s subroutines defining the material model were implemented to update the stresses in the solids elements in LS-DYNA. The model was based on the Johnson-Cook constitutive model with consideration of the mechanical-thermo-chemical coupling effect, which was verified by the experimental results. The results show that the constitutive model developed in this work can describe the impact energy release behavior of the Al/Ni-based RMs.

scholarly journals The impact of corruption on the human security of societies in transition (Iraq case study since 2003)

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ahmed Mohamed Hassan
Keyword(s):  
System Analysis ◽  
Survey Methodology ◽  
Human Security ◽  
National Standards ◽  
Transitional Period ◽  
Strong Impact ◽  
Case Study Methodology ◽  
Content Type ◽  
The Impact

Purpose Iraqi society has suffered from loss or fragility of human security since 2003. The developmental policies, programs and plans of the successive Iraqi Governments throughout the transitional period have not been able to achieve human security, despite the availability of different resources. They have also not prevented or limited the spread of corruption, according to domestic and international reports. Now the country faces a large phenomenon of corruption and the dilemma of human security loss. This study aims to ascertain the nature of the relationship between the phenomenon of corruption and the dilemma of loss or fragility of human security in Iraq since 2003 to learn about the form of this relationship, how the selected variables contribute to the two phenomena and determine the degree of impact of corruption and its dimensions on human security and its components. Design/methodology/approach This research uses the social survey methodology of the sample taken from the Iraqi society and benefits from system analysis approach to identify the inputs and outputs of the variables researched. Moreover, the study uses the case study methodology to collect data and information precisely in an in-depth manner to support qualitative and quantitative analysis and clarifies the situation at the macro level of both phenomena. Findings Findings show the prevalence of corruption structurally in the Iraqi state and society. The contribution of dimensions and selected indicators in the spread of corruption and lack of human security varies. Findings also underline a strong statistical correlation between the two variables and their reverse relationship. In other words, the more the corruption is, the less the opportunities of human security are. There is also a strong impact of corruption and its dimensions on the conditions of human security factors. Practical implications The paper provides profitable findings and recommendations, which can be used by the Iraqi relevant institutions to eliminate corruption, achieve human security and benefit from its indicators in research and development. Originality/value The new addition of this research can be represented by linking the two phenomena and trying to build national standards with the capacity to describe, interpret and predict.

Numerical and Experimental Study on Railway Impact Energy Absorption Using Tube External Inversion Mechanism at Real Scale

2006 ◽  
Vol 306-308 ◽  
pp. 315-320 ◽  
Author(s):  
Ign Wiratmaja Puja ◽  
A. Khairullah ◽  
Muhammad Agus Kariem ◽  
A.H. Saputro
Keyword(s):  
Experimental Study ◽  
Numerical Analysis ◽  
Energy Absorption ◽  
Contact Force ◽  
Impact Energy ◽  
Experimental Result ◽  
Energy Absorber ◽  
The Impact ◽  
Inversion Mechanism ◽  
Real Scale

Impact energy and deceleration at a certain time are the most influenced factor to passenger’s safety when collision between railway vehicles occurred. In this paper, forced external inversion mechanism is considered as impact energy absorber. This mechanism is selected due to its constant inversion load along uniform tube [5] and the impact force is reduced because of its inertia effect [7]. Material used as energy absorber is mild steel. Numerical analysis using finite element method is utilized to study the energy absorption capacity and deceleration characteristic of tube external inversion mechanism for complex transient problem of collision. The real scale experimental study is used to validate the numerical analysis by crashing a moving vehicle to static train series where the impact energy absorber module using external inversion mechanism is attached in the tip of static train series. Characteristic that consider in numerical and experimental study are deformation and contact force. The deformation differences between numerical and experimental study are under 9%. Whereas for contact force, the experimental result of contact force disposed under 8% of numerical result for velocity of moving train at 10 and 15 km/h.

The flexural behaviors of the impacted composite single-lap adhesive joints

2015 ◽  
Vol 22 (5) ◽  
Author(s):  
Emin Ergun ◽  
Hasan Çallioğlu
Keyword(s):  
Experimental Study ◽  
Impact Energy ◽  
Energy Levels ◽  
Composite Plates ◽  
Lap Joints ◽  
Adhesive Joints ◽  
Single Lap Joints ◽  
Impact Tests ◽  
Impact Energies ◽  
The Impact

AbstractThis experimental study deals with the flexural behaviors of composite single-lap adhesive joints after impact tests. Increasing impact energies are applied at the center of the composite plates having three different overlap lengths. It is shown that the overlap lengths and impact energy levels affect considerably the impact responses of the composite single-lap joints. It is also shown that the bending stiffness of the composite increases with increasing overlap length. For this reason, after the impact tests, how these effects influence the flexural behaviors of the impacted composite lap joints was also investigated. The flexural loads of the impacted and non-impacted composite single-lap joints were determined and compared with each other. It is shown that the residual flexural loads after impact increase with increasing overlap lengths but decrease with increasing impact energy.

scholarly journals Design of Bionic Buffering and Vibration Reduction Foot for Legged Robots

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qian Cong ◽  
Xiaojie Shi ◽  
Ju Wang ◽  
Yu Xiong ◽  
Bo Su ◽  
...  
Keyword(s):  
Impact Energy ◽  
Vibration Reduction ◽  
Legged Robots ◽  
Normal Operation ◽  
Natural Vibration Frequency ◽  
Strong Impact ◽  
Legged Robot ◽  
Wide Range ◽  
Unique Shape ◽  
The Impact

When legged robots walk on rugged roads, they would suffer from strong impact from the ground. The impact would cause the legged robots to vibrate, which would affect their normal operation. Therefore, it is necessary to take measures to absorb impact energy and reduce vibration. As an important part of a goat’s foot, the hoof capsule can effectively buffer the impact from the ground in the goat’s running and jumping. The structure of the hoof capsules and its principle of buffering and vibration reduction were studied. Inspired by the unique shape and internal structure of the hoof capsules, a bionic foot was designed. Experimental results displayed that the bionic foot could effectively use friction to consume impact energy and ensured the stability of legged robot walking. In addition, the bionic foot had a lower natural vibration frequency, which was beneficial to a wide range of vibration reduction. This work brings a new solution to the legged robot to deal with the ground impact, which helps it adapt to a variety of complex terrain.

The Affection of Ke of Coal Seam on Strata Behavior

2013 ◽  
Vol 734-737 ◽  
pp. 858-862
Author(s):  
Wen Jie Wang ◽  
Hong Wei Wang ◽  
Zhao Hua Wang ◽  
Duo Xu
Keyword(s):  
Coal Seam ◽  
Impact Energy ◽  
Peak Position ◽  
Vertical Stress ◽  
Energy Index ◽  
Important Indicator ◽  
Stress Peak ◽  
Coal Wall ◽  
Strata Behavior ◽  
The Impact

Coal seam burst tendency is one of the main factors of rockburst. The impact energy index is an important indicator to evaluate bursting liability of coal. The research on the impact of coal seam impact energy index on the mining pressure behavior regularity is important for the rockburst prediction and prevention. This paper used FLAC3D numerical calculation software to simulate the mining process of seam workface with different Ke and studied the strata behavior regularity with different Ke. Calculations indicated that the vertical stress peak increased in the middle of the seam workface with Ke increasing and the peak position closer to face should implement the anti-impact measures. However, with Ke decrease, vertical stress superimposes at peak stress increases sharply, gradually increasing vertical stress peak distance away from the face and roadway coal wall and the peak position of moves away from face and roadway coal wall. Therefore, the stress in the roadway and face superimposed at the scour protection measures should be implemented.

An Assesment of the Impacted Composite Single-Lap Adhesive Joints

2015 ◽  
Vol 31 (4) ◽  
pp. 433-439
Author(s):  
H. Çallioğlu ◽  
E. Ergun
Keyword(s):  
Experimental Study ◽  
Impact Energy ◽  
Energy Levels ◽  
Composite Plates ◽  
Lap Joints ◽  
Adhesive Joints ◽  
Single Lap Joints ◽  
Impact Energies ◽  
The Impact ◽  
Energy Profiling

AbstractThe aim of this experimental study is to investigate impact behaviors of the composite single-lap adhesive joints. The increasing impact energies, which are ranged from approximately 5 J to 30 J, are performed at the center of the composite plates having three different overlap lengths. It is shown that the overlap lengths and impact energy levels affect considerably the impact responses of the composite single lap joints. It is also shown that the bending stiffness of the composite increases by increase in the overlap length. An energy profiling method (EPM) is used to identify the penetration and perforation thresholds of composite lap joints. The damaged composite plates are visually inspected.

scholarly journals An Experimental Study on the Impact Energy Absorption Mechanism of CFRP/Al Compound Square Tube

2015 ◽  
Vol 30 (6) ◽  
pp. 12-17
Author(s):  
Woo Chae Hwang ◽  
Cheon Seok Cha ◽  
Yong Jun Yang ◽  
Jong An Jung ◽  
In Young Yang
Keyword(s):  
Experimental Study ◽  
Energy Absorption ◽  
Impact Energy ◽  
Absorption Mechanism ◽  
The Impact

Experimental study of thermohydraulic characteristics and irreversibility analysis of novel axial corrugated tube with spring tape inserts

2020 ◽  
Vol 92 (3) ◽  
pp. 30901
Author(s):  
Suvanjan Bhattacharyya ◽  
Debraj Sarkar ◽  
Ulavathi Shettar Mahabaleshwar ◽  
Manoj K. Soni ◽  
M. Mohanraj
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Thermal Performance ◽  
Working Fluid ◽  
The Novel ◽  
Heat Exchanger Tube ◽  
Heat Transfer Augmentation ◽  
Corrugated Tube ◽  
The Impact ◽  
Exchanger Tube

The current study experimentally investigates the heat transfer augmentation on the novel axial corrugated heat exchanger tube in which the spring tape is introduced. Air (Pr = 0.707) is used as a working fluid. In order to augment the thermohydraulic performance, a corrugated tube with inserts is offered. The experimental study is further extended by varying the important parameters like spring ratio (y = 1.5, 2.0, 2.5) and Reynolds number (Re = 10 000–52 000). The angular pitch between the two neighboring corrugations and the angle of the corrugation is kept constant through the experiments at β = 1200 and α = 600 respectively, while two different corrugations heights (h) are analyzed. While increasing the corrugation height and decreasing the spring ratio, the impact of the swirling effect improves the thermal performance of the system. The maximum thermal performance is obtained when the corrugation height is h = 0.2 and spring ratio y = 1.5. Eventually, correlations for predicting friction factor (f) and Nusselt number (Nu) are developed.

Sign in / Sign up

Export Citation Format

Share Document