Research on the Calculation Method of Tightening Torque on P-110S Threaded Connections

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Shou-Jun Chen ◽  
Qi An ◽  
Yi Zhang ◽  
Qiang Li

Tightening torque is one of the main factors that could affect the connection quality in threaded connections. On the basis of elastic mechanics and thick cylinder theory, this paper established a new analytical model based on the geometric parameters of thread tooth and the calculation method of tightening torque on P-110S threaded connections was also obtained by calculating the frictional torque on each threaded surface. In this paper, the friction coefficient on the real contact thread tooth was measured by the developed experimental equipment that could be used to simulate the contact of threaded surfaces approximately. By applying the new method on P-110S threaded connection and comparing the results obtained by analytical model with the true make-up torque in application, it could be found that the analytical model and the calculation method proposed in this paper are reasonable. The new method was also validated by using the finite element analysis method to the same sample. The new method proposed in this paper is practical and convenient because it can be applied to calculate the tightening torque just with geometric parameters and thread numbers, which is easier to implement in application.

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Shou-Jun Chen ◽  
Qi An ◽  
Yi Zhang ◽  
Lian-Xin Gao ◽  
Qiang Li

This paper presents a new analytical method that can calculate the load distribution on the thread teeth in cylindrical pipe threaded connection. The new method was developed by analyzing each male and female thread tooth from the connection on the basis of elastic mechanics. By using this method, the load distribution on each thread tooth can be calculated with the tightening torque and thread numbers. By applying the new method on the sample of API 88.9 mm round threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the last four or five threads engaged. By using the finite element analysis method to the same sample validates the new method. The new method proposed in this paper is practical and convenient because it can be applied to calculate the load and deformation on each thread tooth just with tightening torque and thread numbers, which is easier to implement in practice.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Honglin Xu ◽  
Taihe Shi ◽  
Zhi Zhang ◽  
Bin Shi

Loading and contact stress distribution on the thread teeth in tubing and casing premium threaded connections are of great importance for design optimization, pretightening force control, and thread failure prevention. This paper proposes an analytical method based on the elastic mechanics. This is quite different from other papers, which mainly rely on finite element analysis. The differential equation of load distribution on the thread teeth was established according to equal pitch of the engaged thread after deformation and solved by finite difference method. Furthermore, the relation between load acting on each engaged thread and mean contact stress on its load flank is set up based on the geometric description of thread surface. By comparison, this new analytical method with the finite element analysis for a modified API 177.8 mm premium threaded connection is approved. Comparison of the contact stress on the last engaged thread between analytical model and FEM shows that the accuracy of analytical model will decline with the increase of pretightening force after the material enters into plastic deformation. However, the analytical method can meet the needs of engineering to some extent because its relative error is about 6.2%~18.1% for the in-service level of pretightening force.


1999 ◽  
Author(s):  
Mark Hommel

Abstract Predicting the fatigue life of threaded connections using finite element analysis generally requires a 2-D axisymmetric model capable of handling non-axisymmetric loading in order to simulate an applied bending moment. This is desirable from the standpoint of computer run time, as compared with the alternative approach, namely, developing a full 3-D model. Unfortunately, due to their esoteric nature, the 2-D axisymmetric elements with non-axisymmetric loading capability are not supported by the software vendors as well as the other elements, hence pre- and post-processing are more challenging. In addition, due to the Fourier representation of the non-axisymmetric load, computer run time and storage is increased significantly over that of a strictly 2-D axisymmetric model. In view of this, common practice has been to use instead the conventional axisymmetric model with an equivalent applied axial tensile stress equal to the mean bending stress through the wall thickness in order to simulate the bending moment and thereby avoid the necessity for non-axisymmetric loading. The question therefore arises as to how well the results from the strictly axisymmetric model agree with the results from the axisymmetric model with non-axisymmetric loading capability. The purpose of this paper is to compare the results of the two models. A 5-1/2 F.H. threaded connection is modeled by means of a commercial finite element code. First, the axisymmetric model with non-axisymmetric loading capability is treated and results are obtained. Second, the axisymmetric model with applied equivalent tensile load is examined and its results are compared with the former model. It is found that the value of the primary variable of interest for quantification of fatigue life, namely, alternating stress, agrees between the two models within 4%. Thus, it is concluded that the simplified model provides a viable alternative for modeling fatigue life of threaded connections.


2014 ◽  
Vol 526 ◽  
pp. 189-193
Author(s):  
Xiao Lin Wang ◽  
Yan Li

In this paper, it introduces a new method about calculating geometric parameters of hypoidgear. After changing the geometric parameter calculation method made by Gleason company, we can expand 16 solving equations to 20 equations, through establishing three layers of iterative solution conceptions and applying the optimal computation of modern design theory to solve all the geometric parameters, which not only solve the problem about the Gleason method without considering the changing parameters, but also improve the accuracy of the parameters and the stability of the iterative process. Finally, these also lay a foundation for the parametric design of hypoid gear.


2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Shi-kun Lu ◽  
Deng-xin Hua ◽  
Yan Li ◽  
Fang-yuan Cui ◽  
Peng-yang Li

In order to design a reasonable thread connection structure, it is necessary to understand the axial force distribution of threaded connections. For the application of bolted connection in mechanical design, it is necessary to estimate the stiffness of threaded connections. A calculation model for the distribution of axial force and stiffness considering the friction factor of the threaded connection is established in this paper. The method regards the thread as a tapered cantilever beam. Under the action of the thread axial force, in the consideration of friction, the two cantilever beams interact and the beam will be deformed, these deformations include bending deformation, shear deformation, inclination deformation of cantilever beam root, shear deformation of cantilever beam root, radial expansion deformation and radial shrinkage deformation, etc.; calculate each deformation of the thread, respectively, and sum them, that is, the total deformation of the thread. In this paper, on the one hand, the threaded connection stiffness was measured by experiments; on the other hand, the finite element models were established to calculate the thread stiffness; the calculation results of the method of this paper, the test results, and the finite element analysis (FEA) results were compared, respectively; the results were found to be in a reasonable range; therefore, the validity of the calculation of the method of this paper is verified.


2020 ◽  
pp. 136943322098170
Author(s):  
Michele Fabio Granata ◽  
Antonino Recupero

In concrete box girders, the amount and distribution of reinforcements in the webs have to be estimated considering the local effects due to eccentric external loads and cross-sectional distortion and not only the global effect due to the resultant forces of a longitudinal analysis: shear, torsion and bending. This work presents an analytical model that allows designers to take into account the interaction of all these effects, global and local, for the determination of the reinforcements. The model is based on the theory of stress fields and it has been compared to a 3D finite element analysis, in order to validate the interaction domains. The results show how the proposed analytical model allows an easy and reliable reinforcement evaluation, in agreement with a more refined 3D analysis but with a reduced computational burden.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110087
Author(s):  
Feng Zhou ◽  
Han Zhao ◽  
Xiaoke Liu ◽  
Fujia Wang

Permanent magnet linear motors can cause thrust fluctuation due to cogging and end effects, which will affect the operation stability of the linear motor. In order to solve this problem, a new method of eliminating alveolar force by using phase-shifting and displacement is proposed in this paper. Taking the cylindrical permanent magnet linear motor as an example, the traditional cylindrical permanent magnet linear motor is divided into two unit-motors, and established finite element analysis model of cylindrical permanent magnet linear motor. It is different from other traditional methods, the thrust fluctuation was reduced by both phase-shifting and displacement simultaneously in this paper, and through simulation analysis, it is determined that the thrust fluctuation suppression effect was the best when the cogging distance was shifted by half. Furthermore, a comparative simulation was made on whether the magnetic insulating material was used. The simulation results show that: The method proposed in this paper can effectively suppress the thrust fluctuation of the cylindrical permanent magnet linear motor. And it can be applied to other similar motor designs. Compared with the traditional method of suppressing thrust fluctuation, the mechanical structure and the technological process of suppressing thrust fluctuation used in this method are simpler.


Author(s):  
Guido Volterrani ◽  
Carmelo Maggi ◽  
Marco Manetti

Fatigue impacts the life of all components subject to alternating loads, including lube oil injection quills. These occurrences are more frequent if a defect (initial flaw) nucleates in the component due to corrosion, high stress, machining imperfections, etc. The design of components undergoing high fluctuating pressures needs advanced technologies, like autofrettage, and design methods, like FEM or fracture mechanics. This component can be identified as a cylinder with different outside diameters and notches deriving from the geometry variation and threaded connection. The inner diameter is the most stressed area and will require an adequate stress analysis. A sensitivity analysis of the autofrettage pressure can be performed to identify the most appropriate residual stresses on the inner diameter and to obtain a threshold defect larger than the minimum detectable. Fracture mechanics allows the analysis the propagation of an initial defect with materials having different properties and considering different autofrettage pressures. Finite Element Analysis is used to validate the residual stresses predicted by calculation for each autofrettage pressure. An optimized solution of the hypercompressor injection quill can be designed.


2011 ◽  
Vol 314-316 ◽  
pp. 1792-1795
Author(s):  
Hu Huang ◽  
Hong Wei Zhao ◽  
Jie Yang ◽  
Shun Guang Wan ◽  
Jie Mi ◽  
...  

In this paper, a miniaturization nanoindentation and scratch device was developed. Finite element analysis was carried out to study static and modal characteristics of x/y flexure hinge and z axis driving hinge as well as effect of geometric parameters on output performances of z axis driving hinge. Results indicated that x/y flexure hinge and z axis driving hinge had enough strength and high natural frequencies. Geometric parameters of z axis driving hinge affected output performances significantly. The model of developed device was established. Indentation experiments of Si and amorphous alloy showed that the developed miniaturization nanoindentation and scratch device worked well and can carry out indentation experiments with certain accuracy.


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