Methodical Guideline for Bolt-Up Operation of Pipe Flange Connections: A Case Using Sheet Gasket and Spiral Wound Gasket

Author(s):  
Tomohiro Takaki ◽  
Toshimichi Fukuoka

The purpose of this study is the proposal of guidelines for bolt-up operation of pipe flange connections with joint sheet gasket or spiral wound gasket. Numerical calculations are systematically executed for pipe flanges with wide variety of nominal size by using finite element analysis, which can simulate the bolt-up process of a pipe flange connection, because the tightening performance of the pipe flange connection largely depends on the bolt-up process. Gaskets also have dominant effects on the tightening performance. It is, however, impossible to determine the number of tightening passes to get uniform bolt preloads for all kinds of gaskets. A simplified modeling method of nonlinear stress-strain relationship of gasket is, therefore, evaluated and a representative material property of gasket is selected to develop the bolt assembly guideline. The bolt-up procedure, in which four bolts located 90 degrees from each other are tightened with the same magnitude of preload at the installation process, is investigated.

2003 ◽  
Vol 125 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Tomohiro Takaki

It is well known that a large amount of scatter in bolt preloads is observed when bolting up a pipe flange connection, especially in the case of using a spiral wound gasket. In this study, a numerical approach is proposed, which can simulate the bolt-up process of a pipe flange connection with a spiral wound gasket inserted. The numerical approach is designed so as to predict the scatter in bolt preloads and achieve uniform bolt preloads at the completion of pipe flange assembly. To attain the foregoing purposes, the stress-strain relationship of a spiral wound gasket, which shows highly nonlinear behavior, is identified with a sixth-degree polynomial during loading and with an exponential equation during unloading and reloading. Numerical analyses are conducted by three-dimensional FEM, in which a gasket is modeled as groups of nonlinear one-dimensional elements.


2018 ◽  
Vol 775 ◽  
pp. 554-559 ◽  
Author(s):  
Ravivat Rugsaj ◽  
Chakrit Suvanjumrat

This research aimed to find an appropriated hyperelastic material model for the finite element analysis (FEA) of a non-pneumatic tire (NPT). The innovative method involving water jet cutting technique was performed to prepare the tensile and compressive test specimens from the non-pneumatic tire, TWEEL, which was developed by Michelin. The stress-strain relationship of material testing results was fitted to select the suitable constitutive model. The FEA was performed and compared to the physical experiment to validate the hyperelastic material model. The suitable hyperelastic material model can be used in the development of NPT for the further work.


2013 ◽  
Vol 419 ◽  
pp. 203-208
Author(s):  
Ying Yu ◽  
Yao Run Peng ◽  
Shi Xin Lan ◽  
Ping Zhou

Wave spring is a key component of multi-disc wet clutch and the response speed and running quality of multi-disc wet clutch is affected by its characteristics. This paper analyses the theoretical calculation of load-deformation relationship of wave spring. The load-deformation relationship of wave spring is obtained by ANSYS10.0 software according to its structural characteristics and actual boundary condition and compared with the calculated results based on different methods and the measured value, and then study the effect of the wave number on the load-deformation relationship of wave spring. The results show that the calculated value of finite element analysis (FEM) is closer to the measured value and the FEM has more advantages on simulation of the working performance of wave spring.


Author(s):  
Toshiyuki Sawa ◽  
Naofumi Ogata

This paper deals with the stress analysis of a pipe flange connection with a spiral wound gasket using the elasto-plastic finite element method taking account the hysteresis and the non-linearity in the stress-strain curve of the spiral wound gasket, when an intemal pressure is applied to the pipe flange connections with the different nominal diameters from 2″ to 20″. The effects of the nominal diameter of the pipe flange on the contact stress distributions at the interfaces are examined. Leakage tests of the pipe flange connections with 3″ and 20″ nominal diameters were conducted and measurement of the axial bolt force was also performed. The results by the finite element analysis are fairly consistent with the experimental results concerning the variation in the axial bolt force. By using the contact stress distributions and the results of the leakage test, the new gasket constants are evaluated. As a result, it is found that the variations in the contact stress distributions are substantial due to the flange rotation in the pipe flange connections with the larger nominal diameter. In addition, a method to determine the bolt preload for a given tightness parameter is demonstrated.


1983 ◽  
Vol 10 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Hisham Hafez ◽  
George Abdel-Sayed

The present paper introduces some improvements in the finite element analysis of soil–steel structures. It applies two-noded spring-type interface elements and accounts for the compaction effects during construction simulation. The analyses are performed in increments using a hyperbolic stress–strain relationship for the nonlinear behaviour of the soil and take into account the shear or tension failure in the soil elements. Also, a combination of constant and compatible linear strain elements for soil is used to increase the accuracy of the analysis around the conduit while keeping the storage requirement and computation time for the numerical solution manageable.The analytical results show satisfactory agreement with those obtained experimentally. They also show that the American Association of State Highway and Transportation Officials (AASHTO) provisions overestimate the thrust due to live load and underestimate the thrust due to dead load. A better comparison is found with the Ontario Highway Bridge Design Code (OHBDC).


2016 ◽  
Vol 08 (06) ◽  
pp. 1650082 ◽  
Author(s):  
Liang Zhang ◽  
Huiting Zhang ◽  
Jian Wu ◽  
Bo Yan ◽  
Mengkai Lu

Bi-modulus materials have different moduli in tension and compression and the stress–strain relation depends on principal stress that is unknown before displacement is determined. Establishment of variational principle is important for mechanical analysis of materials. First, parametric variational principle (PVP) is proposed for static analysis of bi-modulus materials and structures. A parametric variable indicating state of principal stress is included in the potential energy formulation and the nonlinear stress–strain relation is evolved into a linear complementarity constraint. Convergence of finite element analysis is thus improved. Then the proposed variational principle is extended to a dynamic problem and the dynamic equation can be derived based on Hamilton’s principle. Finite element analysis of nacreous bio-composites is performed, in which a unilateral contact behavior between two hard mineral bricks is modeled using the bi-modulus stress–strain relation. Effective modulus of composites can be determined numerically and stress mechanism of “tension–shear chain” in nacre is revealed. A delayed effect on stress propagation is found around the “gaps” between mineral bricks, when a tension force is loaded to nacreous bio-composites dynamically.


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