Finite Element Analysis of Von-Mises Stress Distribution in a Spherical Shell of Liquified Natural Gas (Lng) Pressure Vessels

ABSTRACT

This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values.

This research work investigated the modeling of Von Mises stress in LNG Spherical Carbon Steel Storage tank using assumed displacement Finite Element analysis based on shallow shell triangular elements. Using equations of elasticity, constant thickness carbon steel spherical storage tanks were subjected to different loading conditions. This paper stresses the need for proper definition of shallow element using sector angles to obtain the shallowness. The shallow spherical triangular element has five degrees of freedom at each of its corner node, which are the essential external degrees of freedom. The assumed displacement fields of these shallow triangular elements satisfied the exact requirement of rigid body modes of motion. The FORTRAN 90 programming language was used for the programme coding to solve finite element equations resulting from the model while Von Mises stresses distribution within the spherical storage tank shell subjected to different internal pressures were determined. The results showed that the use of non-shallow elements due to improper sector angles resulted in unreliable results while real shallow elements produced results that tallied with ASME Section VIII Div 1, Part UG values.

Cite this paper

nullO. Adeyefa and O. Oluwole, "Finite Element Analysis of Von-Mises Stress Distribution in a Spherical Shell of Liquified Natural Gas (Lng) Pressure Vessels,"*Engineering*, Vol. 3 No. 10, 2011, pp. 1012-1017. doi: 10.4236/eng.2011.310125.

nullO. Adeyefa and O. Oluwole, "Finite Element Analysis of Von-Mises Stress Distribution in a Spherical Shell of Liquified Natural Gas (Lng) Pressure Vessels,"

References

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[2] J.-H. Kim, H.-S. Seo, K.-W. Lee and I.-S. Yoon, “Development of the World’s Largest above-Ground Full Containment LNG Storage Tank,” 23rd World Gas Conference, Amsterdam, 6 June 2006.

[3] E. M. Sosa, “Computational Buckling Analy-sis of Cylindrical Thin-Walled above-Ground Tanks,” Ph.D. Thesis, The University of Puerto Rico Mayaguez Campus, Mayaguez, June 2005.

[4] J. Dong, et al., “Numerical Calculation and Analysis of Single—Curvature Polyhedron Hydro-Bulging Process for Manufacturing Spherical Vessels,” Institute of Nuclear Energy Technology, Tsinghua University, Beijing 2005.

[5] P. Pourcel, et al., “A Seismic Post Elastic Behaviour of Spherical Tanks,” TECHNIP France and DY-NALIS France, 1999, pp. 1-14.

[6] Y. Dong and D. Redekop, “Structural and Vibrational Analysis of Liquid Storage Tanks,” Transactions, SMiRT 19, Department of Mechanical Engineering, University of Ottawa, Ottawa, 2007.

[7] E. Reissner, “On Some Problems in Shell Theory,” Proceedings, 1st Symposium on Naval Structural Mechanics, Stanford University, Pergaman Press Inc., New York, 1960.

[8] H. L. Langhaar, “Energy Methods in Applied Mechanics,” Wiley & Sons, New York, 1962.

[1] J. H. Kim, et al., “Preliminary Earthquake Response Analysis of 200,000 Kilolitres Large Capacity above- Ground LNG Storage Tank for the Basic Design Sec- tion,” Institute of Construction Technology, DAEWOO E&C Co., Ltd., 2005.

[2] J.-H. Kim, H.-S. Seo, K.-W. Lee and I.-S. Yoon, “Development of the World’s Largest above-Ground Full Containment LNG Storage Tank,” 23rd World Gas Conference, Amsterdam, 6 June 2006.

[3] E. M. Sosa, “Computational Buckling Analy-sis of Cylindrical Thin-Walled above-Ground Tanks,” Ph.D. Thesis, The University of Puerto Rico Mayaguez Campus, Mayaguez, June 2005.

[4] J. Dong, et al., “Numerical Calculation and Analysis of Single—Curvature Polyhedron Hydro-Bulging Process for Manufacturing Spherical Vessels,” Institute of Nuclear Energy Technology, Tsinghua University, Beijing 2005.

[5] P. Pourcel, et al., “A Seismic Post Elastic Behaviour of Spherical Tanks,” TECHNIP France and DY-NALIS France, 1999, pp. 1-14.

[6] Y. Dong and D. Redekop, “Structural and Vibrational Analysis of Liquid Storage Tanks,” Transactions, SMiRT 19, Department of Mechanical Engineering, University of Ottawa, Ottawa, 2007.

[7] E. Reissner, “On Some Problems in Shell Theory,” Proceedings, 1st Symposium on Naval Structural Mechanics, Stanford University, Pergaman Press Inc., New York, 1960.

[8] H. L. Langhaar, “Energy Methods in Applied Mechanics,” Wiley & Sons, New York, 1962.