scholarly journals Optimization of the Structural Parameters and the Teeth Shape of Slip in Drill Rig

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hua Zhang ◽  
Qianwei Zhu ◽  
Bin Gao

In order to improve the performance of slip and reduce the extrusion damage of the drill pipe in the drill rig, the optimization of structural parameters and teeth shape of the slip while clamping the drill pipe had been researched in this article. On the macroscale, the structural parameters of the slip had been optimized with response surface method (RSM) and Multiobjective Genetic Algorithm (MOGA). The optimized result showed that the single weight of the slip had been reduced from 3.99 kg to 2.91 kg and the maximum deformation of the drill pipe was reduced from 3.75 mm on both sides to 2.56 mm on both sides. On the microscale, a mathematical model for the single slip teeth while clamping the drill pipe had been established to give a detailed description to calculate the equivalent coefficient of friction and provide the relationship between the frictional torque with the allowable compression strength. In addition, the finite element model that had been set up by ABAQUS was used to verify the mathematical model, and the comparison of results had shown the accuracy of the mathematical model of the slip teeth while clamping the drill pipe. According to the mathematical model of the slip teeth in the drill rig, while clamping the drill pipe, the optimal shape of the slip teeth in the drill rig was achieved under the following condition: the slope of the slip teeth θ is 60°, the top width of the slip teeth w h is 1.5 mm, and the depth of the slip teeth clamping the drill pipe d is 0.5 mm. The equivalent coefficient of friction f v can be increased from 1.73 to 2.06, and the optimal result f v increases 11.3%.

2010 ◽  
Vol 145 ◽  
pp. 317-320
Author(s):  
Chun Ming Zhang ◽  
Run Yuan Hao

This text is on the basis of the investigation of the 42MN flatting mill’s higher beam, establishing the flatting mill’s higher beam’s finite element model and the mathematical model which has optimum structure. According to the results of their structure finite element analysis, weaved the relevant procedures and optimized them, obtained ideal structural parameters, this text provide better ideas and ways for the structural design of the flatting mill’s higher beam.


2011 ◽  
Vol 383-390 ◽  
pp. 2850-2855 ◽  
Author(s):  
Shu Lin Wang ◽  
Bo Zhou ◽  
Wei Zhan Zhang ◽  
Zhi Jie Yang ◽  
Gang Liu

According to the principle of induction heating, the skin depth of shrink-fit chuck is determined and the mathematical model of induction heating is constructed. Then a finite element model of induction heating for shrink-fit chuck based on FEM software is set up and the electromagnetic field, temperature field and structure field are obtained. In the end, the paper discusses the influence of the position, current frequency and current density of the coil on the deflection of the clamping bore. Research work provides a theory reference for the design of shrink-fit tool holder and shrink-fit machine.


1991 ◽  
Vol 24 (5) ◽  
pp. 85-96 ◽  
Author(s):  
Qingliang Zhao ◽  
Zijie Zhang

By means of simulated tests of a laboratory–scale oxidation pond model, the relationship between BOD5 and temperature fluctuation was researched. Mathematical modelling for the pond's performance and K1determination were systematically described. The calculation of T–K1–CeCe/Ci) was complex but the problem was solved by utilizing computer technique in the paper, and the mathematical model which could best simulate experiment data was developed. On the basis of experiment results,the concept of plug–ratio–coefficient is also presented. Finally the optimum model recommended here was verified with the field–scale pond data.


2014 ◽  
Vol 945-949 ◽  
pp. 777-780
Author(s):  
Tao Liu ◽  
Yong Xu ◽  
Bo Yuan Mao

Firstly, according to the structure characteristics of precision centrifuge, the mathematical model of its dynamic balancing system was set up, and the dynamic balancing scheme of double test surfaces, double emendation surfaces were established. Then the dynamic balance system controller of precision centrifuge was designed. Simulation results show that the controller designed can completely meet the requirements of precision centrifuge dynamic balance control system.


2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.


2013 ◽  
Vol 572 ◽  
pp. 636-639
Author(s):  
Xi Chen ◽  
Gang Wang

This paper deals with the walking stability analysis of a multi-legged crablike robot over slope using normalized energy stability margin (NESM) method in order to develop a common stabilization description method and achieve robust locomotion for the robot over rough terrains. The robot is simplified with its static stability being described by NESM. The mathematical model of static stability margin is built so as to carry out the simulation of walking stability over slope for the crablike robot that walks in double tetrapod gait. As a consequence, the relationship between stability margin and the height of the robots centroid, as well as its inclination relative to the ground is calculated by the stability criterion. The success and performance of the stability criterion proposed is verified through MATLAB simulation and real-world experiments using multi-legged crablike robot.


Author(s):  
Debraj Sarkar ◽  
Debabrata Roy ◽  
Amalendu Bikash Choudhury ◽  
Sotoshi Yamada

Purpose A saturated iron core superconducting fault current limiter (SISFCL) has an important role to play in the present-day power system, providing effective protection against electrical faults and thus ensuring an uninterrupted supply of electricity to the consumers. Previous mathematical models developed to describe the SISFCL use a simple flux density-magnetic field intensity curve representing the ferromagnetic core. As the magnetic state of the core affects the efficient working of the device, this paper aims to present a novel approach in the mathematical modeling of the device with the inclusion of hysteresis. Design/methodology/approach The Jiles–Atherton’s hysteresis model is utilized to develop the mathematical model of the limiter. The model is numerically solved using MATLAB. To support the validity of model, finite element model (FEM) with similar specifications was simulated. Findings Response of the limiter based on the developed mathematical model is in close agreement with the FEM simulations. To illustrate the effect of the hysteresis, the responses are compared by using three different hysteresis characteristics. Harmonic analysis is performed and comparison is carried out utilizing fast Fourier transform and continuous wavelet transform. It is observed that the core with narrower hysteresis characteristic not only produces a better current suppression but also creates a higher voltage drop across the DC source. It also injects more harmonics in the system under fault condition. Originality/value Inclusion of hysteresis in the mathematical model presents a more realistic approach in the transient analysis of the device. The paper provides an essential insight into the effect of the core hysteresis characteristic on the device performance.


2020 ◽  
Vol 22 (3) ◽  
pp. 132-139
Author(s):  
A. V. Denisov ◽  
M. D. Stepanov ◽  
N. A. Haraldin ◽  
A. V. Stepanov ◽  
A. I. Borovkov ◽  
...  

Abstract. In the work, a review of scientific articles on the behavior of tissues and organs of the human body under local mechanical effects on it, as well as a description of the physico-mechanical properties of biological materials. The selection of mechanical behavior for each biological material as part of a mathematical model of the human torso was carried out, its finite element model was created, validation experiments were modeled using data presented in the literature. An original calculation model of a human torso with a tuned interaction of organs with each other was developed. Contact interaction parameters are determined. The developed computational model of a human torso was verified based on data from open sources for an experiment with mechanical action by a cylindrical impactor. An algorithm for processing pressure and acceleration graphs has been implemented in order to obtain tolerance curves. A specialized modular program has been created for the automated processing of calculation results and the output of the main results. 42 numerical tests were carried out simulating the entry of a steel ball into each of 21 zones for power engineers of 40 and 80 J. According to the results of the tests for each organ, pressure and acceleration tolerance curves were obtained, animations of the behavior of organs under shock were created, visualization of the pressure field propagation in organs was obtained torso.


2020 ◽  
Author(s):  
Chun-Hua Du ◽  
Yan-Chao Zhang ◽  
Ya-Hui Cui ◽  
Shu-Na Dong ◽  
Hong-Hu Ji ◽  
...  

Abstract In order to accurately predict the hysteresis characteristics of finger seal, the minimum hysteresis which can directly reflect the hysteresis of finger seal is proposed to characterize the hysteresis of finger seal. The mathematical model for calculating the minimum hysteresis of finger seal is established, the correction coefficient in the mathematical model is determined, and the mathematical model is verified by experiments. The influence of the structure and working condition parameters of finger laminates on the hysteresis characteristics is studied based on the modified calculation model, and the rule of influence is obtained in the end. Research results show that the maximum error between the leakage characteristics numerical calculation of finger seal base on modified calculation model and the experiment results is 7.64%, and the mathematical model of the minimum hysteresis is reasonable and reliable. The descending order of influence degree of structural parameters on the hysteresis characteristics of finger seal is: thickness of each finger laminate, finger repeat angle, arc radius of the finger beam arcs‘ centers, diameter of the finger base circle, width of the interstice between fingers, arc radius of finger beam. The research results provide a theoretical basis for further research on the influence of hysteresis on the finger seal leakage characteristics and the optimal design of finger seal structure.


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