Simulation Research on the Influence of the Clearance to the Impact Contact Characteristics between Coal Gangue and the Clearance-Contained Tail Beam Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-14 ◽  
Author(s):  
Yang Yang ◽  
Zhengyuan Xin ◽  
Qingliang Zeng ◽  
Zhihai Liu
Keyword(s):  
Finite Element ◽  
Test Point ◽  
Coal Gangue ◽  
Radial Clearance ◽  
Beam Test ◽  
Beam Structure ◽  
Hydraulic Support ◽  
Contact Behavior ◽  
Contact Response ◽  
The Impact

There are various forms of clearance at the connection of various parts of the hydraulic support. However, the influence of clearance has been ignored in various related research studies of the hydraulic support. In order to clearly grasp the accurate impact contact response law between coal gangue and the hydraulic support, the radial clearance in the pin shaft connection structure of the tail beam is considered for the first time in this paper. By constructing the theoretical contact model of the pin shaft connection, the difficulty of studying the interaction between coal gangue and the hydraulic support through theoretical solution is proved. On this basis, the finite element contact simulation analysis method is proposed to study the impact contact behavior between coal gangue and the tail beam. This paper constructed the finite element impacting simulation model between coal gangue and the radial clearance-contained tail beam structure and carried out impact contact simulation between coal gangue and the multiple clearance-contained tail beam structure as well as the changing clearance-contained tail beam structure, respectively, and contact responses of the tail beam structure such as the spring stress, the pin shaft test point stress, acceleration, and velocity of the tail beam test point under different working conditions are obtained. The influence law of clearance on different contact responses is studied, and the differences of contact responses after coal gangue impact between two clearance-contained tail beam structures and three clearance-contained tail beam structures are compared and analyzed. Research results show that, in the condition of multiclearance, the amplitude of each contact response when gangue is impacted is greater than that of coal. When the radial clearance of the connection unit increases from 0 to 0.25 mm, the overall fluctuation amplitude of the contact responses decreases. In 3-clearance state, increase of the radial clearance size of the connection unit will lead to the increase of the spring stress, the stress of the pin shaft test point, and the velocity of the tail beam test point gradually and the decrease of the acceleration of the tail beam test point. Throughout the research, the vibration response of the pin shaft can be taken as coal gangue recognition parameter. The work provides a theoretical basis for the study of the influence law of clearance on hydraulic support and provides a reference for the study of contact behavior between coal gangue and the hydraulic support.

scholarly journals Dynamic Response Analysis of the Coal Gangue-like Elastic Rock Sphere Impact on the Massless Tail Beam Based on Contact-Structure Theory and FEM

2019 ◽  
Vol 2019 ◽  
pp. 1-24
Author(s):  
Yang Yang ◽  
Lirong Wan ◽  
Zhengyuan Xin
Keyword(s):  
Contact Structure ◽  
Simulation Method ◽  
Hydraulic Cylinder ◽  
Coal Gangue ◽  
Structure Theory ◽  
Response Analysis ◽  
Hydraulic Support ◽  
Finite Element Software ◽  
Contact Response ◽  
The Impact

The impact and collision behavior between the coal gangue and the hydraulic support widely exists in the top coal caving. However, due to the complex interactions between the large number of coal gangue particles in the mining surface and the limitations of the coal mining technology and other factors, it becomes a difficult problem to study the collision behavior and the contact response between the coal gangue and the hydraulic support or its main components under the actual caving conditions. In order to accurately grasp the contact response law when the coal gangue impacts the tail beam of the hydraulic support, in combination with the equivalent stiffness of the tail beam jack, the Lankarani–Nikravesh (L-N) nonlinear spring-damping contact model, the structural mechanics model of the tail beam, and the energy conservation law, this paper firstly establishes the system contact-structure dynamic model when the particles impact on the tail beam based on the tail beam equivalent kinematics model. Then, to further study the system contact response, the spring damper module is used in the finite element software for the first time to replace the hydraulic cylinder, and four different types of the rigid-flexible coupling simulations when the impact heights, the impact positions, the rock radii, and the rock materials change are conducted, respectively. Through the combination of the theory and the simulation, the contact response law when the particles impacting the massless tail beam under different working conditions is obtained, and the system contact response differences as well as the coal gangue identifying feasibility on the basis of the response differences after the coal gangue impact are analyzed. The conclusions will provide theoretical reference and simulation method for the study of the impact-contact behavior between the coal gangue and the hydraulic support.

Finite-element analysis of multi-body contacts for pile driving using a hydraulic pile hammer

2011 ◽  
Vol 225 (5) ◽  
pp. 1153-1161 ◽  
Author(s):  
Y Guo ◽  
J P Hu ◽  
L Y Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Test Point ◽  
Pile Driving ◽  
Penalty Function Method ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Material Choice ◽  
Multi Body ◽  
The Impact

This article treats the pile driving as multi-body dynamic contacts. By using the penalty function method and three-dimensional model of finite-element method, the dynamic process of pile driving is acquired and a method for choosing the cushion material of the hydraulic pile hammer to improve driving efficiency is proposed. The process of pile driving in the real situation of an industrial experiment is simulated. The results of stress on test point are consistent with the test point. By analysing the stress distributed along the direction of pile radius and pile axis, the rule of the stress distribution on the pile is concluded. The rule for cushion material choice is obtained by comparing the influence for the impact stress with different elastic modulus ratio of the hammer cushion to the pile and the pile cushion to the pile.

The Finite Element Analysis of Lei-Ring Applied to Upright Column for Hydraulic Support

2014 ◽  
Vol 635-637 ◽  
pp. 541-544
Author(s):  
Hai Ning Li ◽  
Dan Li ◽  
Xin Xin
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Equivalent Stress ◽  
Element Model ◽  
Hydraulic Support ◽  
Working Pressure ◽  
Element Analysis ◽  
Sealing Performance ◽  
Sealing Ring ◽  
The Impact

Abstract:In this paper ,the finite element model of the lei-ring was established in ANSYS software,the sealing performance of hydraulic support column piston was analyzed.Also,the numerical simulation analysis was made of the impact of column working pressure on the sealing performance,and a series of the integrated equivalent stress and contact pressure images of sealing ring when working were got. From those images,the location most prone to failure can be concluded.All of work can provide a theoretical reference for the design and use of drum sealing ring used on hydraulic support upright column.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

A Fracture Mechanics Based Parametric Study of the Copper-to-Copper Direct Thermo-Compression Bonded Interface Using Finite Element Method

2013 ◽  
Author(s):  
Ah-Young Park ◽  
Satish Chaparala ◽  
Seungbae Park
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parametric Study ◽  
Initial Crack ◽  
Bonding Interface ◽  
Interface Condition ◽  
Large Temperature ◽  
Bonded Interface ◽  
The Impact ◽  
Element Method

Through-silicon via (TSV) technology is expected to overcome the limitations of I/O density and helps in enhancing system performance of conventional flip chip packages. One of the challenges for producing reliable TSV packages is the stacking and joining of thin wafers or dies. In the case of the conventional solder interconnections, many reliability issues arise at the interface between solder and copper bump. As an alternative solution, Cu-Cu direct thermo-compression bonding (CuDB) is a possible option to enable three-dimension (3D) package integration. CuDB has several advantages over the solder based micro bump joining, such as reduction in soldering process steps, enabling higher interconnect density, enhanced thermal conductivity and decreased concerns about intermetallic compounds (IMC) formation. Critical issue of CuDB is bonding interface condition. After the bonding process, Cu-Cu direct bonding interface is obtained. However, several researchers have reported small voids at the bonded interface. These defects can act as an initial crack which may lead to eventual fracture of the interface. The fracture could happen due to the thermal expansion coefficient (CTE) mismatch between the substrate and the chip during the postbonding process, board level reflow or thermal cycling with large temperature changes. In this study, a quantitative assessment of the energy release rate has been made at the CuDB interface during temperature change finite element method (FEM). A parametric study is conducted to analyze the impact of the initial crack location and the material properties of surrounding materials. Finally, design recommendations are provided to minimize the probability of interfacial delamination in CuDB.

scholarly journals The High-Rate Sealed MRPC to Promote Pollutant Exchange in Gas Gaps: Status on the Development and Observations

2021 ◽  
Vol 11 (11) ◽  
pp. 4722
Author(s):  
Botan Wang ◽  
Xiaolong Chen ◽  
Yi Wang ◽  
Dong Han ◽  
Baohong Guo ◽  
...  
Keyword(s):  
Gas Flow ◽  
High Rate ◽  
Stable Operation ◽  
Beam Test ◽  
High Luminosity ◽  
Rate Test ◽  
3D Printed ◽  
Resistive Plate Chambers ◽  
The Impact ◽  
Current Behavior

This work reports the latest observations on the behavior of two Multigap Resistive Plate Chambers (MRPC) under wide high-luminosity exposures, which motivate the development and in-beam test of the sealed MRPC prototype assembled with low-resistive glass. The operation currently being monitored, together with previous simulation results, shows the impact of gas pollution caused by avalanches in gas gaps, and the necessity to shrink the gas-streaming volume. With the lateral edge of the detector sealed by a 3D-printed frame, a reduced gas-streaming volume of ~170 mL has been achieved for a direct gas flow to the active area. A high-rate test of the sealed MRPC prototype shows that, ensuring a 97% efficiency and 70 ps time resolution, the sealed design results in a stable operation current behavior at a counting rate of 3–5 kHz/cm2. The sealed MRPC will become a potential solution for future high luminosity applications.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Geometrically nonlinear static and dynamic analysis of CNT reinforced laminated composite plates: A finite element study

2021 ◽  
pp. 095440622110089
Author(s):  
Balakrishna Adhikari ◽  
BN Singh
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Dynamic Response ◽  
Integration Scheme ◽  
Static And Dynamic Analysis ◽  
Finite Element Study ◽  
Nonlinear Eigenvalues ◽  
Nonlinear Static ◽  
The Impact ◽  
Element Study

In this paper, a finite element study is conducted using the Green Lagrange strain field based on vonKarman assumptions for the geometric nonlinear static and dynamic response of the laminated functionally graded CNT reinforced (FG-CNTRC) composite plate. The governing equations for determining the nonlinear static and dynamic behavior of the FG-CNTRC plate are derived using the Lagrange equation of motion based on Reddy's higher order theory. Using the direct iteration technique, the nonlinear eigenvalues for analyzing the free vibration response are obtained and the nonlinear dynamic responses of the FG-CNTRC plate are encapsulated based on the nonlinear Newmark integration scheme. The impact of the amplitude of vibration on mode switching phenomena and the consequence of the duration of the pulse on the free vibration regime of the plate are outlined. Also, the effect of time dependent loads is studied on the normal stresses of the plate. Furthermore, the impact on the nonlinear static and dynamic response of the laminated FG-CNTRC plate of various parameters such as span-thickness ratio (b/h ratio), aspect ratio (a/b ratio), different edge constraints, CNT fiber gradation, etc. are also studied.

Investigation on the shaft voltage generation of large synchronous turboalternators

2020 ◽  
Vol 39 (5) ◽  
pp. 1145-1156
Author(s):  
Kevin Darques ◽  
Abdelmounaïm Tounzi ◽  
Yvonnick Le-menach ◽  
Karim Beddek
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Short Circuit ◽  
Element Model ◽  
Stator Winding ◽  
Content Type ◽  
Voltage Generation ◽  
The Impact ◽  
Investigation Process ◽  
Circulating Currents

Purpose This paper aims to go deeper on the analysis of the shaft voltage of large turbogenerators. The main interest of this study is the investigation process developed. Design/methodology/approach The analysis of the shaft voltage because of several defects is based on a two-dimensional (2D) finite element modeling. This 2D finite element model is used to determine the shaft voltage because of eccentricities or rotor short-circuit. Findings Dynamic eccentricities and rotor short circuit do not have an inherent impact on the shaft voltage. Circulating currents in the stator winding because of defects impact the shaft voltage. Originality/value The original value of this paper is the investigation process developed. This study proposes to quantify the impact of a smooth stator and then to explore the contribution of the real stator winding on the shaft voltage.

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