scholarly journals Design of a New Type of Torsional Impactor and Analysis of Its Impact Performance

2021 ◽  
Vol 11 (22) ◽  
pp. 11037
Author(s):  
Xianfeng Tan ◽  
Zongtao Chen ◽  
Songcheng Tan ◽  
Longchen Duan ◽  
Chao Xu ◽  
...  
Keyword(s):  
Rotation Speed ◽  
Impact Force ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Impact Angle ◽  
Impact Frequency ◽  
Stick Slip ◽  
Transmission Shaft ◽  
New Type ◽  
The Impact

In view of the stick-slip phenomenon in deep and hard rock drilling, a new type of torsional impactor that can provide torsional impact vibration was designed. According to the working principle and structural characteristics of the designed torsional impactor, this paper theoretically analyzes the influences of different structural parameters and motion parameters on the impact frequency, impact force, and impact torque of the torsional impactor. The results show that the impact frequency f is directly proportional to the rotational speed VZ of the transmission shaft and the installed number n of torsional impact generating devices. Additionally, the impact force F is directly proportional to sine value of the impact angle α (i.e., sinα), impact hammer mass m, impact hammer rotation speed VZ (i.e., transmission shaft rotation speed), and impact hammer rotation radius r and is inversely proportional to action time Δt of the impact hammer and impact anvil. Furthermore, the impact torque M is directly proportional to the impact force F and rotary radius r of the impact hammer. This article lays a foundation for further theoretical and experimental research of torsional impactors and provides a reference for the design and testing of torsional impactors.

scholarly journals Experimental Study on Axial Impact Mitigating Stick-Slip Vibration with a PDC Bit

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yong Wang ◽  
Hongjian Ni ◽  
Yiliu (Paul) Tu ◽  
Ruihe Wang ◽  
Xueying Wang ◽  
...  
Keyword(s):  
Impact Force ◽  
Impact Load ◽  
Similarity Theory ◽  
Impact Frequency ◽  
Stick Slip ◽  
Axial Impact ◽  
Pdc Bit ◽  
Fluctuation Amplitude ◽  
Rotary Speed ◽  
The Impact

Stick-slip vibration reduces the drilling rate of penetration, causes early wear of bits, and threatens the safety of downhole tools. Therefore, it is necessary to study suppression methods of stick-slip vibration to achieve efficient and safe drilling. Field tests show that the use of downhole axial impactors is helpful to mitigate stick-slip vibration and improve rock-breaking efficiency. However, there are many deficiencies in the study of how axial impact load affects stick-slip vibration of a PDC bit. In this paper, based on the two-degrees-of-freedom spring-mass-damper model and similarity theory, a laboratory experiment device for suppressing stick-slip vibration of a PDC bit under axial impact load has been developed, and systematic experimental research has been carried out. The results show that the axial impact force can suppress the stick-slip vibration by reducing the amplitude of weight on bit and torque fluctuations and by increasing the main frequency of torque. The amplitude of impact force affects the choice of the optimal back-rake angle. The impact frequency is negatively correlated with the fluctuation amplitude of the rotary speed. When the impact frequency is greater than 100 Hz, the fluctuation amplitude of the rotary speed will not decrease.

Analysis on the Impact Force of a Ship Colliding with a Bridge Pier

2012 ◽  
Vol 193-194 ◽  
pp. 693-701
Author(s):  
Jian Guo Ding ◽  
Zhi Qiao
Keyword(s):  
Mechanical Model ◽  
Mass Velocity ◽  
Impact Force ◽  
Impact Angle ◽  
Bridge Pier ◽  
Velocity Coefficient ◽  
The Impact

Because many accidents in China involve a ship in a barge fleet colliding with a bridge pier, determining the impact force of the ship is important. To obtain an equation that describes the impact force of a ship colliding with a bridge pier, a mechanical model of the collision is simplified, and the results from other researchers are applied. Based on the equation, it is found that the impact force of a ship colliding with a bridge pier is not only relevant to the mass，velocity, board thicknesses of the ship, and the impact angle, but also to the remaining velocity coefficient. It has been demonstrated that the result from the proposed equation in this paper is in accordance with that of Gkss’s test in Wosin G theory.

Mathematical Modeling of High Energy Ball Milling (HEBM) Process

2014 ◽  
Vol 353 ◽  
pp. 126-130 ◽  
Author(s):  
Maya Radune ◽  
A. Radune ◽  
Svetlana Lugovskoy ◽  
M. Zinigrad ◽  
David Fuks ◽  
...  
Keyword(s):  
Reasonable Agreement ◽  
Rotation Speed ◽  
Weight Ratio ◽  
High Energy ◽  
Impact Angle ◽  
Velocity Impact ◽  
Calculation Results ◽  
Angle Rotation ◽  
Energy Ball ◽  
The Impact

In the present study the modeling of the HEBM process is presented. The impact velocity, impact angle, rotation speed, mass of balls, ball-to-powder weight ratio and time of milling have been taken into account in order to calculate the energy transferred from the balls to the powder. Two different systems, namely, TiN-AlN and polysalicylic acid were experimentally investigated in order to confirm the validity of the model. The calculation results are in a reasonable agreement with the results of experimental research.

scholarly journals Influence of Adhesion Properties on the Crash Behavior of Steel/Polymer/Steel Sandwich Crashboxes: An Experimental Study

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1400 ◽  
Author(s):  
Mohamed Harhash ◽  
Moritz Kuhtz ◽  
Jonas Richter ◽  
Andreas Hornig ◽  
Maik Gude ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Failure Modes ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Failure Behavior ◽  
Adhesion Properties ◽  
Polymer Adhesion ◽  
Strong Adhesion ◽  
Materials Used ◽  
The Impact

The energy absorption behavior of crashboxes made of steel/polymer/steel (SPS) sandwich sheets can be influenced by numerous parameters, such as the materials used, their thicknesses and stacking, and the adhesion properties between their layers. Therefore, in the present study, the impact of steel/polymer adhesion quality on the occurring failure modes of the crashboxes and the resulting energy absorptions are experimentally analyzed. For this purpose, axial crushing and three-point bending tests on double-hat and top-hat crash boxes were performed, respectively. Three levels of adhesion quality are investigated: none, weak, and strong adhesion strengths. Additionally, the structural crash properties, such as energy absorption and maximal intrusion, are determined and analyzed at both of the quasi-static and highly dynamic loading rates. The results of these investigations show that the adhesion strengths chosen here significantly influence both the failure modes and the energy absorption values. In particular, the structural parameters, in the case of no adhesion, are at most half of those in the case of strong adhesion. However, it is also shown that, in the case of weak adhesion, the structural characteristics are slightly reduced. Based on these results, the possibility to adjust the adhesion strength—globally and/or locally—could be used in future activities to purposefully tailor the failure behavior of hybrid crashboxes.

Research and Field Application of the Axial-Torsional Coupled Percussion Drilling Technology

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Zongjie Mu ◽  
Gensheng Li ◽  
Zhongwei Huang ◽  
Jingbin Li ◽  
Hengyu Song
Keyword(s):  
Impact Force ◽  
Field Application ◽  
Fluid Density ◽  
Direct Proportion ◽  
Impact Frequency ◽  
Axial Impact ◽  
Pump Rate ◽  
Drilling Technology ◽  
The Impact ◽  
Percussion Drilling

Abstract Enhancing the rate of penetration (ROP) is one of the goals pursued by the oil and gas drilling industry. It has been proved that percussion drilling is a feasible method to increase drilling efficiency. However, single percussion drilling technology (axial percussion or torsional percussion) cannot cater to the current needs. This paper proposed a new technology/tool called the axial-torsional coupled percussion drilling, which can use the advantages of the percussion drilling in a better way. Mechanical structure and working principle of this tool were first introduced in detail and the theoretical analysis of the impact force and the impact frequency were then conducted. It was found that both the axial impact force and the torsional impact force are in direct proportion to the fluid density and are in direct proportion to the square of the pump rate. Both the axial impact frequency and the torsional impact frequency are in direct proportion to the pump rate and are in direct proportion to the square root of the fluid density. Subsequently, a laboratory experiment was conducted to verify the above theoretical results. The tools were applied to the oil field in Xin Jiang province, China. Field application results indicate that the penetration rate of the test well is averagely 1.6–3.3 times as fast as that of the adjacent well.

Development of a high-frequency torsional impact generator for improving drilling efficiency

2013 ◽  
Vol 228 (11) ◽  
pp. 1968-1977 ◽  
Author(s):  
Xiaohua Zhu ◽  
Liping Tang
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Impact Frequency ◽  
Element Analysis ◽  
Stick Slip ◽  
Deep Wells ◽  
Experimental Apparatus ◽  
The Finite Element Analysis ◽  
Drilling Technology ◽  
The Impact

The drilling of deep wells has to face problems to suppress stick-slip vibrations, especially for tough formations. Such problems induce frequent tool failures and poor well quality. Torsional impact drilling is an emerging drilling technology for improving the productivity of oil and gas by mitigating the stick-slip vibration. In this paper, a high-frequency torsional impact generator has been developed in order to investigate this drilling technology. Mechanism of torsional impact as a means of stick-slip mitigation is studied. Structure and operating principle of the tool have been presented. The finite element analysis approach is utilized in the analysis of applicability of the impact unit which is most significant for the tool. The analysis indicates that the impact unit operates successfully. An experimental apparatus is developed to examine the applicability of the proposed numerical method to the analysis of the impact unit. Laboratory tests with different impact frequency are conducted with the apparatus. It is verified that the impact system operates regularly, and high-frequency torsional impacts are generated. In addition, impact parameters of the apparatus which will be helpful to the study of the high-frequency torsional impact drilling are obtained.

Initial response mechanism and local contact stiffness analysis of the floating two-stage buffer collision-prevention system under ship colliding

2021 ◽  
pp. 136943322098610
Author(s):  
Kai Lu ◽  
Xu-Jun Chen ◽  
Zhen Gao ◽  
Liang-Yu Cheng ◽  
Guang-Huai Wu
Keyword(s):  
Kinetic Energy ◽  
Impact Force ◽  
Contact Stiffness ◽  
Impact Angle ◽  
Bridge Pier ◽  
Two Stage ◽  
Collision Prevention ◽  
Prevention System ◽  
The Impact ◽  
Depth Curves

A floating two-stage buffer collision-prevention system (FTBCPS) has been proposed to reduce the impact loads on the bridge pier in this paper. The anti-collision process can be mainly divided into two stages. First, reduce the ship velocity and change the ship initial moving direction with the stretching and fracture of the polyester ropes. Second, consume the ship kinetic energy with the huge damage and deformation of the FTBCPS and the ship. The main feature of the FTBCPS lies in the first stage and most of the ship kinetic energy can be dissipated before the ship directly impacts on the bridge pier. The contact stiffness value between the ship and the FTBCPS can be a significant factor in the first stage and the calculation method of it is the focus of this paper. The contact force, the internal force and the general equation of motion have been given in the first part. The structure model of the ship and the FTBCPS are then established in the ANSYS Workbench. After that, 38 typical load cases of the ship impacting on the FTBCPS are conducted in LS-DYNA. The reduction processes of the ship kinetic energy and the ship velocity in different load cases have been investigated. It can be summarized that the impact angle and the ship initial velocity are the main factors in the energy and velocity dissipation process. Moreover, the local impact force-depth curves have also been studied and the impact angle is found to be the only significant factor on the ship impact process. Next, the impact force-depth curves with different impact angles are fitted and the contact stiffness values are accordingly calculated. Finally, the impact depth range, the validity of the local simulation results and the consistency of the fitted stiffness value are verified respectively, demonstrating that the fitted stiffness values are applicable in the global analysis.

scholarly journals Optimization of a Self-Excited Pulsed Air-Water Jet Nozzle Based on the Response Surface Methodology

2021 ◽  
Vol 67 (3) ◽  
pp. 75-87
Author(s):  
Yong Wang ◽  
Xiaolin Wang ◽  
Zilong Zhang ◽  
Yu Li ◽  
Houlin Liu ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Impact Force ◽  
Structural Parameters ◽  
Coupling Factor ◽  
Industrial Applications ◽  
Water Jet ◽  
Force Amplitude ◽  
Before And After ◽  
The Impact

A self-excited pulsed air-water jet (SEPAWJ) offers many advantages over other jets and has a large number of practical and industrial applications. In order to take better advantage of the SEPAWJ, response surface methodology (RSM) models were established with the experimental impact force characteristics as the dependent variable and three key nozzle parameters as the independent variable. Single and coupling factor effects of these three parameters (oscillation chamber length, oscillation chamber height, and diameter of the downstream nozzle) on performance of nozzle are analysed, and the structural parameters of optimum performance are calculated using RSM models. The external flow field, impact force and cleaning performance of SEPAWJ before and after optimization are analysed and compared experimentally. It is found that the significance levels of established average impact force and impact force amplitude RSM models are lower than 0.05, and their error ratios between calculation and experiment under the optimum construction are both less than 5 %, which confirms their considerable reliability. Meanwhile, the final large water mass of optimized SEPAWJ is formed much earlier, and is more intensive and more concentrated. Compared with the original SEPAWJ nozzle, the impact force and impact force amplitude of optimized SEPAWJ nozzle are increased by 52.00 % and 38.26 %, respectively. In addition, the cleaned area ratio of nozzle before and after optimization is 76 % and 100 % at 50 seconds, respectively, with an increase of 22.4 %.

scholarly journals EXPERIMENT ON IMPACT DAMAGE OF CASTOR CAPSULE AND ITS INFLUENCING FACTORS OPTIMIZATION

2020 ◽  
Vol 61 (2) ◽  
pp. 87-96 ◽  
Author(s):  
Junming Hou ◽  
Yong Yang ◽  
Hongjie Zhu ◽  
Weixue Hu
Keyword(s):  
Water Content ◽  
Impact Force ◽  
Impact Damage ◽  
Impact Angle ◽  
Maximum Deformation ◽  
Combination Optimization ◽  
Damage Degree ◽  
Castor Seeds ◽  
Maximum Impact Force ◽  
The Impact

Castor is an important oil crop. Impact damage is critical in the process of castor capsule shelling, directly affecting the shelling effect of castor seeds. An experiment was taken to investigate it. To study the damage degree of castor capsule under the impact, water content, impact height, and impact angle were taken as test factors, and the maximum impact force and normal deformation were taken as test indexes. The combination optimization was carried out through the multi-objective genetic algorithm. The results show that the impact height has a significant effect on the maximum deformation (p<=0.01), and the water content and impact angle have a significant impact on the impact force (p<=0.05). The height and angle have a significant impact on the deformation (p<=0.01), and the water content has a significant impact on the deformation (p<=0.05).

Impact Indentation Properties and Interfacial Strength of Ceramic Coatings

2010 ◽  
Vol 654-656 ◽  
pp. 1972-1977
Author(s):  
Yi Wang Bao ◽  
Kun Ming Li ◽  
De Tian Wan ◽  
Xue Qiang Cao
Keyword(s):  
Impact Force ◽  
Steel Substrate ◽  
Impact Resistance ◽  
Interfacial Strength ◽  
Ceramic Coatings ◽  
Impact Angle ◽  
Zro2 Coating ◽  
Aluminum Substrates ◽  
The Impact ◽  
Peak Impact Force

Spherical impact indentation tests with different impact angles (90°, 60°, 45°, and 30°) were carried out to understand the impact resistance and interfacial adhesion of zirconia (ZrO2) ceramic coating on steel and aluminum substrates, respectively. A linear rail with an adjustable impact angle was used to guide the slipping impact head to impact the specimen. It is found that the peak impact force for surface damage decreases but the contact indentation becomes longer with decreasing impact angle. Under almost the same peak impact force, the smaller the impact angle, the higher the impulse. The experimental results indicate that the ZrO2 coating on steel substrate has higher impact resistance than that on the aluminum substrate. The cross bonded test results show that ZrO2 coating on both steel and aluminum substrates exhibit excellent interfacial tensile and shear strength.

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