Finite Element Analysis of O-ring Sealing Performance of Manned Submersible Viewports

2020 ◽  
Vol 20 (5) ◽  
pp. 1628-1637
Author(s):  
J. X. Li ◽  
P. F. Liu ◽  
S. B. Wang ◽  
J. X. Leng
2013 ◽  
Vol 774-776 ◽  
pp. 25-29
Author(s):  
Cong Fang Hu ◽  
Yuan Qiang Tan

Based on the tandem sealing structure at the end of the shaft,a finite element model of rubber O-rings has been established and the sealing performance of rubber O-ring has been analyzed. There is an un-uniform compression among these O-rings which lead to the sealing failure. Under different friction factors, several groups of the rubber O-rings have been analyzed, finding that the friction factor is the reason of un-uniform compression. The effect of different average compression rate has been investigated, which has been integrated in the sealing criteria for the tandem O-rings, providing a reference for the optimization of tandem sealing structure at the end of the shaft. According to the sealing criteria for a single O-ring, the sealing criteria for the tandem O-rings is built.


2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091868
Author(s):  
Shuang Jing ◽  
Anle Mu ◽  
Yi Zhou ◽  
Ling Xie

The seal is the key part of the cone bit. To reduce the failure probability, a new seal was designed and studied. The sealing performance and structure optimization of the X-O composite seal was analyzed and compared by finite-element analysis. The stress and contact pressure were analyzed to establish the main structural parameters that affect sealing performance and the direction of the structural optimization. By optimizing these structural parameters, including the height, and the radial and axial arc radii, an optimized structure is obtained. The results show that (1) the X-O composite seal can meet the seal requirement, the excessive height of the X seal ring is the root cause of the uneven distribution of stress, pressure, and distortion. (2) A new seal structure is obtained, the distribution of pressure and stress is reasonable and even, and the values of stress and pressure are reduced to avoid distortion and reduce the wear. Finally, the field test results of the X-O composite seal of cone bit showed that the service life of the bit bearing increased by 16% on average and the drilling efficiency increased by 11% on average compared with the original cone bit with the O seal ring.


Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Quanbin Ren ◽  
Jie Hong

First, this paper established the seal structural 2D axisymmetric model of a certain Solid Rocket Booster (SRB) and calculated the deformation and stresses at ignition through a large displacement, incompressible, contact finite element analysis. The results show that the maximum contact stress appears at the contact area and the maximum shear stress at groove notch. Then, some typical parameters of the seal structure which might have the impact on the sealing performance, such as the gap breadth, initial compressibility, fillets of the groove notch and bottom, groove width, were analyzed. We can find that the gap breadth and initial compressibility do great contributions to the maximum contact normal stress, and the groove notch and bottom fillets act upon the maximum shear stress obviously. In order to verify the validity of the 2D axisymmetric model, 3D structural finite element analysis of the structure was conducted, and the results indicate that in service, the upper flange is inclined relative to the nether flange, which seems to mean that the gap breadth can not be considered as a constant during the 2D axisymmetric analysis. However further calculations say that if using the minimum gap breadth gotten in 3D analysis as its constant gap value, the above 2D axisymmetric model can rationally take the place of 3D model to analyze the sealing performance. Finally, the failure modes & criteria of the O-ring seals based on the maximum contact normal stress and shear stress were determined to ensure the reliability of this structure.


Author(s):  
Satoshi Nagata ◽  
Toshiyuki Sawa ◽  
Takashi Kobayashi ◽  
Hirokazu Tsuji

This paper reports the results of finite element analysis representing the sealing performance tests on the slip-on type pipe flange connections for 8 inch and 16 inch. The flange connections are subjected to internal pressure and bending moment. Internal pressure is applied by helium gas and the bending moment is loaded through 4 points bending equipment. Gas leak rates are measured by pressure decay method. During the test, the variations in the axial bolt force are monitored for all the bolts by strain gages. The pipe stress at the junction of pipe and flange is also measured. Finite element analysis simulates the tests and the simulated results are compared with the measured data. Then the behaviors of the slip-on type flange connections under internal pressure and bending moment as well as the sealing performance are clarified by the experiment and the finite element simulation.


Author(s):  
Quan Han ◽  
Yan Zhang ◽  
Haiyang Chen ◽  
Juekuan Yang ◽  
Yunfei Chen

In order to complete the mating and demating operations of the electrical connectors for underwater applications in the deep water environment, the pressure-balanced oil-filled (PBOF) structures are designed to compensate the huge water pressure. This paper focuses on the sealing performance of three sealing systems used in connectors, including the O-ring seals, rectangular seals, and U-cup seals. A method coupled the finite element analysis and elastohy-drodynamic lubrication (EHL) numerical model is presented to describe the issue. Results show that the rectangular seals perform best in fluid leakage, and O-ring seals are better in reducing the friction force. The oil leakages of the seals increase with the speed while the seawater leakages remain roughly constant. And the oil leakages of all the seals are larger than the seawater leakage. Types of seal rings, fluid viscosity and operation speed of connector can all influence the sealing performance of wet-mate connectors.


2015 ◽  
Vol 750 ◽  
pp. 324-329
Author(s):  
He Hui Wang ◽  
Ya Juan Feng ◽  
Wen Min Zhu ◽  
Zhi Ming Zhang

Since external loads affect the sealing performance of bolted flanged joints, this paper calculated external loads of bolted flanged joints by using CAESAR II software and evaluated the effects of external loads on the sealing performance from the viewpoint of changes in contact gasket stress and flange rotation by using ANSYS software. The FE results showed that the contact gasket stress decreases a lot at the tension side and increases a little at the compression side. The paper also evaluated the stress distribution in bolted flanged joints subjected to external loads. The results suggested that the flange rotation and the overall stress increased compared with that of flange without external loads. External loads can induce unexpected leakage and strength failure of the bolted flanged joints during operation.


2014 ◽  
Vol 556-562 ◽  
pp. 615-619
Author(s):  
Guo Liang Zhang ◽  
Zhi Bin Zeng

In the hydraulic and pneumatic equipments, the elastomeric O-ring gaskets are widely used to ensure their sealing. The sealing capability of an elastomeric O-ring gasket depends upon the contact stresses that develop between the O-ring and the surfaces with which it comes into contact. In order to increase the strength and service life of the general elastomeric O-ring gasket, this gasket including metal skeleton is gradually applied to the actual product in recent years. In spite of the sealing performance of the elastomeric O-ring gasket has been investigated in many literatures, few information of it is known about the elastomeric O-ring gasket including metal skeleton. If any gasket degrades or fails, the overall operation and performance of the production will be affected. This paper aims to study the contact stresses occurred on the metal skeleton seal structure under the various interference fits with three sectional forms (trapezoid cross section, square cross section and circular cross section). Finite element analysis is used to predict sealing performance of an installed metal skeleton seal, providing a normal force against the sealing surface. Results gained show that the contact stresses occurred on the metal skeleton seal is larger than it generated on the general elastomeric O-ring gasket. Furthermore, the metal skeleton seal possessed trapezoid cross section can produce the maximum contact stress, which will show the best sealing performance among three sectional forms.


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