Investigating peak stresses in fitting and repair patches of buried polyethylene gas pipes
Reza KHADEMI ZAHEDI1(), Pouyan ALIMOURI2, Hooman KHADEMI ZAHEDI3, Mohammad SHISHESAZ2
1. Institute of Structural Mechanics, Bauhaus-Universit?t Weimar, Mariensrtaße 15, Weimar 99423, Germany 2. Mechanical Engineering Department, Shahid Chamran University of Ahvaz, Ahvaz, Iran 3. Mechanical Engineering Department, Islamic Azad University, North Tehran Branch, Iran
Nowadays, polyethylene composes a large number of natural gas distribution pipelines installed under the ground. The focus of the present contribution is two fold. One of the objectives is to investigate the applicability of polyethylene fittings in joining polyethylene gas pipes which are electrofused onto the pipe ends and buried under the ground, by estimating stress distribution using finite element method. The second objective is to study the effectiveness of polyethylene repair patches which are used to mend the defected pipelines by performing a finite element analysis to calculate peak stress values. Buried polyethylene pipelines in the natural gas industry, can be imposed by sever loadings including the soil-structure interaction, traffic load, soil’s column weight, internal pressure, and thermal loads resulting from daily and/or seasonal temperature changes. Additionally, due to the application of pipe joints, and repair patches local stresses superimposed on the aforementioned loading effects. The pipe is assumed to be made of PE80 resin and its jointing socket, and the repair patch is PE100 material. The computational analysis of stresses and the computer simulations are performed using ANSYS commercial software. According to the results, the peak stress values take place in the middle of the fitting and at its internal surface. The maximum stress values in fitting and pipe are below the allowable stresses which shows the proper use of introduced fitting is applicable even in hot climate areas of Ahvaz, Iran. Although the buried pipe is imposed to the maximum values of stresses, the PE100 socket is more sensitive to a temperature drop. Furthermore, all four studied patch arrangements show significant reinforcing effects on the defected section of the buried PE gas pipe to transfer applied loads. Meanwhile, the defected buried medium density polyethylene gas pipe and its saddle fused patch can resist the imposed mechanical and thermal loads of 22°C temperature increase. Moreover, increasing the saddle fusion patch length to 12 inches reduces the maximum stress values in the pipe, significantly.
A J Peacock. Handbook of Polyethylene: Structures, Properties, and Applications. New York: Marcel Dekker, 2000
2
R Khademi-Zahedi, P Alimouri. Finite element model updating of a large structure using multi-setup stochastic subspace identification method and bees optimization algorithm. Frontiers of Structural and Civil Engineering, 2018, 13(4): 965–980
3
M Makvandi, H Bahmani, R Khademi-Zahedi. Technical analysis of the causes of blowout in BiBi-Hakimeh well No. 76. In: Proceedings of the National Conference in New Research of Industry and Mechanical Engineering. Tehran: Civilica, 2015, 17–18 https://doi.org/https://www.civilica.com/Paper-NRIME01-NRIME01_066.html
4
R Khademi-Zahedi, M Makvandi, M Shishesaz. The applicability of casings and liners composite patch repair in Iranian gas and oil wells. In: Proceedings of the 22nd Annual International Conference on Mechanical Engineering—ISME2014. Ahvaz: Civilica, 2014 https://doi.org/https://www.civilica.com/Paper-ISME22-ISME22_351.html
5
R Khademi-Zahedi, M Makvandi, M Shishesaz. Technical analysis of the failures in a typical drilling mud pump during field operation. In: Proceedings of the 22nd Annual International Conference on Mechanical Engineering—ISME2014. Ahvaz: Civilica, 2014 https://doi.org/https://www.civilica.com/Paper-ISME22-ISME22_347.html
6
C F Popelar. Characterization of mechanical properties for polyethylene gas pipe materials. Thesis for the Master’s Degree. Columbus: The Ohio State University, 1989
7
A J Peacock. Handbook of Polyethylene, Structures, Properties, and Applications. Texas: Exxon Chemical Company, Bayton, 2000
8
C F Cullis, M Hirschler. The Combustion of Organic Polymers. Oxford: Clarendos Press, 1981
9
R Khademi Zahedi, P Alimouri, H Nguyen-Xuan, T Rabczuk. Crack detection in a beam on elastic foundation using differential quadrature method and the Bees algorithm optimization. In: Proceedings of the International Conference on Advances in Computational Mechanics. Singapore: Springer, 2017, Vol 36, 439–460
10
P Areias, M A Msekh, T Rabczuk. Damage and fracture algorithm using the screened Poisson equation and local remeshing. Engineering Fracture Mechanics, 2016, 158: 116–143 https://doi.org/10.1016/j.engfracmech.2015.10.042
11
T Rabczuk, S Bordas, G Zi. On three-dimensional modelling of crack growth using partition of unity methods. Computers & Structures, 2010, 88(23–24): 1391–1411 https://doi.org/10.1016/j.compstruc.2008.08.010
12
T Rabczuk, G Zi, S Bordas, H Nguyen-Xuan. A geometrically nonlinear three dimensional cohesive crack method for reinforced concrete structures. Engineering Fracture Mechanics, 2008, 75(16): 4740–4758 https://doi.org/10.1016/j.engfracmech.2008.06.019
13
T Rabczuk, T Belytschko. Application of particle methods to static fracture of reinforced concrete structures. International Journal of Fracture, 2006, 137(1–4): 19–49 https://doi.org/10.1007/s10704-005-3075-z
14
P R Budarapu, T Rabczuk. Multiscale methods for fracture: A review. Journal of the Indian Institute of Science, 2017, 97(3): 339–376 https://doi.org/10.1007/s41745-017-0041-5
15
A H N Shirazi, R Abadi, M Izadifar, N Alajlan, T Rabczuk. Mechanical responses of pristine and defective C3N nanosheets studied by molecular dynamics simulations. Computational Materials Science, 2018, 147: 316–321 https://doi.org/10.1016/j.commatsci.2018.01.058
16
B Mortazavi, T Rabczuk. Anisotropic mechanical properties and strain tuneable band-gap in single-layer SiP, SiAs, GeP and GeAs. Physica E: Low-dimensional Systems and Nanostructures, 2018, 103: 273–278 https://doi.org/10.1016/j.physe.2018.06.011.
17
F Zhuo-Jia, X Qiang, C Wen, A H D Cheng. A boundary-type meshless solver for transient heat conduction analysis of slender functionally graded materials with exponential variations. Journal of Sound and Vibration, 2018, 425: 170–188
18
S Zhou, X Zhuang, H Zhu, T Rabczuk. Phase field modelling of crack propagation, branching and coalescence in rocks. Theoretical and Applied Fracture Mechanics, 2018, 96: 174–192 https://doi.org/10.1016/j.tafmec.2018.04.011
19
S Zhou, X Zhuang, T Rabczuk. A phase-field modeling approach of fracture propagation in poroelastic media. Engineering Geology, 2018, 240: 189–203 https://doi.org/10.1016/j.enggeo.2018.04.008
20
S Zhou, T Rabczuk, X Zhuang. Phase field modeling of quasi-static and dynamic crack propagation: COMSOL implementation and case studies. Advances in Engineering Software, 2018, 122: 31–49 https://doi.org/10.1016/j.advengsoft.2018.03.012
21
C Zhang, C Wang, T Lahmer, P He, T Rabczuk. A dynamic XFEM formulation of crack identification. International Journal of Mechanics and Materials in Design, 2016, 12(4): 427–448 https://doi.org/10.1007/s10999-015-9312-3
22
P Budarapu, R Gracie, S Bordas, T Rabczuk. An adaptive multiscale method for quasi-static crack growth. Computational Mechanics, 2014, 53(6): 1129–1148 https://doi.org/10.1007/s00466-013-0952-6
23
H Talebi, M Silani, S Bordas, P Kerfriden, T Rabczuk. A computational library for multiscale modelling of material failure. Computational Mechanics, 2014, 53(5): 1047–1071 https://doi.org/10.1007/s00466-013-0948-2
24
T Rabczuk, G Zi, S Bordas, H Nguyen-Xuan. A geometrically non-linear three dimensional cohesive crack method for reinforced concrete structures. Engineering Fracture Mechanics, 2008, 75(16): 4740–4758 https://doi.org/10.1016/j.engfracmech.2008.06.019
25
F Amiri, C Anitescu, M Arroyo, S Bordas, T Rabczuk. XLME interpolants, a seamless bridge between XFEM and enriched meshless methods. Computational Mechanics, 2014, 53(1): 45–57 https://doi.org/10.1007/s00466-013-0891-2
26
T Rabczuk, G Zi. A meshfree method based on the local partition of unity for cohesive cracks. Computational Mechanics, 2007, 39(6): 743–760 https://doi.org/10.1007/s00466-006-0067-4
27
T Rabczuk, P M A Areias, T Belytschko. A meshfree thin shell method for nonlinear dynamic fracture. International Journal for Numerical Methods in Engineering, 2007, 72(5): 524–548 https://doi.org/10.1002/nme.2013
28
T Rabczuk, P M A Areias. A meshfree thin shell for arbitrary evolving cracks based on an external enrichment. CMES-Computer Modeling in Engineering and Sciences, 2006, 16(2): 115–130
29
T Rabczuk, G Zi, S Bordas, H Nguyen-Xuan. A simple and robust three dimensional cracking-particle method without enrichment. Computer Methods in Applied Mechanics and Engineering, 2010, 199(37–40): 2437–2455 https://doi.org/10.1016/j.cma.2010.03.031
30
T Rabczuk, T Belytschko. A three dimensional large deformation meshfree method for arbitrary evolving cracks. Computer Methods in Applied Mechanics and Engineering, 2007, 196(29–30): 2777–2799 https://doi.org/10.1016/j.cma.2006.06.020
31
R Rafiee, F. Reshadi Simulation of functional failure in GRP moral pipes. Journal of composite structures, 2014, 113: 155–163
32
R K Watkins, L R Anderson. Structural Mechanics of Buried Pipes. New York: CRC Press, 2000, 22–57
33
Plastics Pipe Institute. Handbook of Polyethylene Pipe. Washington, D. C.: Plastics Pipe Institute, Inc., 2006, 261–303
34
Plastics Pipe Institute. Polyethylene Gas Pipes Systems, UponorAldyl Company Installation Guide. Washington, D. C.: Plastics Pipe Institute, Inc., 2004
35
J B Goddard. Plastic Pipe Design. Technical Report 4.103. 1994
36
A P Moser, S Folkman. Buried Pipe Design 2. New York: The McGraw-Hill Companies, 2001
37
A, Kolonko C Madryas. Modernization of underground pipes in towns in Poland. Infrastructure, 1996, 11: 215–220
38
R Khademi-Zahedi. Stress Distribution in Patch Repaired Polyethylene Gas Pipes. Thesis for the Master’s Degree. Ahvaz: Shahid Chamran University, 2011
39
R Khademi-Zahedi. Application of the finite element method for evaluating the stress distribution in buried damaged polyethylene gas pipes. Underground Space, 2019, 4(1): 59–71 https://doi.org/10.1016/j.undsp.2018.05.002.
40
R Khademi-Zahedi, M Shishesaz. Application of a finite element method to stress distribution in buried patch repaired polyethylene gas pipe. Underground Space, 2019, 4(1): 48–58 https://doi.org/10.1016/j.undsp.2018.05.001.
41
A Nasirian. Investigating the application of polyethylene gas pipes for gas transportation. Thesis for the Master’s Degree. Ahvaz: Shahid Chamran University, 2007
42
M Shishesaz, M R Shishesaz. Applicability of medium density polyethylene gas pipes in hot climate areas of south-west Iran. Iranian Polymer Journal, 2008, 17: 503–517
43
Chevron Phillips Chemical Company LP. Buried pipe Design. Bull: Chevron Phillips Chemical Company LP, 2003, 81–115
44
AASHTO. Standard Specifications for Transportation Materials and Methods of Sampling and Testing. 15th ed. Washington D. C.: American Association of State Highway and Transportation Officials, 1990
45
Plastic Pipe and Building Products. ASTM Annual Book of ASTM Standards. Philadelphia, PA: American Society for Testing and Material, 1991
46
The Plastics Pipe Institute. Handbook of Polyethylene Pipe. Washington D. C.: Plastics Pipe Institute, Inc., 2006,157–260
47
Corrugated Polyethylene Pipe Association. Structural Design Method for Corrugated Polyethylene Pipe. Washington D. C.: Corrugated Polyethylene Pipe Association, 2000
48
International Organization For Standardization. ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications—Classification and designation—Overall Service (design) coefficient. ISO, 2004
