Abstract
Shallow domes subjected to external pressure are extensively used in missile structures. The critical failure mode for these domes is buckling due to external pressure. Different closed form solutions are available to evaluate buckling pressure of dome shapes like ellipsoid and torisphere. The torisiphere dome is the optimum dome shape among conventional domes. Shape optimization is carried out to find the optimal dome shape among shallow domes subjected to external pressure. Dome geometry is generalized by cubic bezier polynomials. For carrying out shape optimization, a low fidelity model is preferred which can predict the critical buckling pressure of a general dome shape. Towards this a unified model is proposed which meets the above requirement. Using this unified model, shape optimization of dome for minimization of mass is carried out subjected to buckling constraint. The study yielded a dome shape different from conventional dome shapes with a mass saving of 6% over torispherical dome while meeting the buckling constraint. The results of unified model are also validated with high fidelity Finite Element Analysis.
Similar content being viewed by others
Abbreviations
- a:
-
Semi major axis of ellipse
- b:
-
Semi minor axis of ellipse
- BLF:
-
Buckling load factor of dome
- E:
-
Young’s modulus of dome material
- P:
-
External pressure acting on dome
- P cr :
-
Critical buckling pressure of dome
- R:
-
Radius of hemispherical dome
- R crown :
-
Crown radius of torispherical dome
- R ell :
-
Equivalent radius of ellipsoidal dome
- R knu :
-
Knuckle radius of torispherical dome
- R max :
-
Equivalent radius of general shape dome
- R tor :
-
Equivalent radius of torispherical dome
- s:
-
Parameter of bezier polynomial
- t:
-
Thickness of dome
- X i , Y i :
-
Control point coordinates of bezier polynomial
References
Anon (1969) Buckling of thin-walled doubly curved shells. National Aeronautics and Space Administration
Anon (2006) Specification for unfired fusion welded pressure vessels: PD 5500: 2006. BSI
Blachut J (1988) Optimally shaped torispheres with respect to buckling and their sensitivity to axisymmetric imperfections 29(6):975–981. doi:10.1016/0045-7949(88)90323-9
Blachut J, Galletly GD (1988) Clamped torispherical shells under external pressure some new results. The Journal of Strain Analysis for Engineering Design 23(1):924. doi:10.1243/03093247v231009
Firl M, Bletzinger KU (2012) Shape optimization of thin walled structures governed by geometrically nonlinear mechanics. Comput Methods Appl Mech Eng 237-240:107117. doi:10.1016/j.cma.2012.05.016
Singer J, Arbocz J, Weller T (2002) Buckling experiments experimental methods in buckling of thin-walled structures. John Wiley & Sons, Inc
Sisk D (1993) Low profile bulkheads for launch vehicle propellant tanks - an optimum system solution. Space Programs and Technologies Conference and Exhibit. doi:10.2514/6.1993-4223
Smeltzer S, Bowman L (2002) Buckling design studies of inverted, oblate bulkheads for a propellant tank. In: 43rd AIAA/ASME/ASCE/AHS/ASC structures, structural dynamics, and materials conference. doi:10.2514/6.2002-1525
Smith P, Blachut J (2008) Buckling of externally pressurized prolate ellipsoidal domes. Transactions of ASME Journal of Pressure Vessel Technology 130
Wu K, Lepsch JR (1999) Nontangent, developed contour bulkheads for a wing-body single stage launch vehicle. In: 37th aerospace sciences meeting and exhibit. doi:10.2514/6.1999-835
Yang M, Liang C, Chen C (1992) A rational shape design of externally pressurized torispherical dome ends under buckling constraints. Comput Struct 43(5):839–851. doi:10.1016/0045-7949(92)90298-e
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
R, S., Ismail, S., P. C., J. et al. Shape optimization of shallow domes subjected to external pressure. Struct Multidisc Optim 57, 903–908 (2018). https://doi.org/10.1007/s00158-017-1773-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00158-017-1773-6