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International Journal of Fracture

, Volume 10, Issue 4, pp 537–544 | Cite as

The fracture of spherical shells under pressure and circular tubes with angled cracks in torsion

  • P. D. Ewing
  • J. G. Williams
Article

Abstract

Experiments are reported on spherical PMMA domes with thickness variations. The results were correlated with the parameter a2/Rt where I is a mean thickness based on equivalent energy. The curvature effect could be adequately represented by a published formulae. Crack angles and failure stresses for tubes broken in torsion were compared with the maximum hoop stress and minimum strain energy theories of Sih.

Keywords

PMMA Spherical Shell Hoop Stress Curvature Effect Failure Stress 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Résumé

On rapporte des essais réalisés sur des domes sphériques en polyméthacrylate de méthyle (PMMA). Les résultats obtenus ont W mis en corrélations avec le paramètre α2/REE est une épaisseur moyenne établie sur base d'une énergie équivalente. L'effet de la courbure peut être adéquatement rendu en utilisant les formules publiées dans la littérature.

On a également comparé les angles de la fissuration et les contraintes de rupture, dans le cas de tubes rompus par torsion, aver la contrainte maximale de membrane et les théories de l'énergie de déformation minimum proposées par Sih.

Zusammenfassung

Versuche auf runden Kuppeln aus PMMA mit veränderlicher Dicke werden beschrieben. Die Korrelation zwischen den Ergebnissen and dem Parameter a2/RE wind aufgestellt wo E die mittlere Dicke auf die Vergleichsenergie begründet, darstellt. Der Krümmungseffekt kann sehr gut mit einer Formel aus der Litteratur erfaßt werden. Rißwinkel und Bruchspannungen unter Torsion gebrochener Röhren werden mit der Theorie der größten Membranspannung und der niedrigsten Verformungsenergie von Sih verglichen.

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References

  1. [1]
    J. G. Williams and P. D. Ewing, Crack propagation in plates and shells subjected to bending and direct loading, Proceedings of the 2nd International Conference on Fracture, Brighton, April (1969).Google Scholar
  2. [2]
    J. G. Williams and P. D. Ewing, Fracture under complex stress—the angled crack problem, International Journal of Fracture Mechanics, 8, 4 (1972).Google Scholar
  3. [3]
    J. G. Williams, A method of calculation for thermoforming plastics sheets, Journal of Strain Analysis, 5, 1 (1970).Google Scholar
  4. [4]
    G. P. Marshall and J. G. Williams, Correlation of fracture data for PMMA, Journal of Materials Science, 8 (1973).Google Scholar
  5. [5]
    E. S. Folias, A finite line crack in a pressurized spherical shell, International Journal of Fracture Mechanics, 1, 1 (1965).Google Scholar
  6. [6]
    E. S. Folias, On the theory of fracture of curved sheets, Engineering Fracture Mechanics, 2, 2 (1970).Google Scholar
  7. [7]
    G. C. Sib and H. C. Hagendorf, A new theory of spherical shells with cracks, Lehigh University technical report ONR-TR-73-3.Google Scholar
  8. [8]
    F. Erdogan and G. C. Sib, On the crack extension in plates under plane loading and transverse shear, Trans. ASME, Journal Basic Engineering, 85D (1963) 519.Google Scholar
  9. [9]
    G. C. Sib and M. E. Kipp, Discussion on “Fracture under complex stress-the angled crack problem”. (By J. G. Williams and P. D. Ewing). International Journal of Fracture, 10, 2 (1974).Google Scholar
  10. [10]
    G. C. Sih (Editor), Methods of Analysis and Solutions of Crack Problems, Noordhoff International Publishing (1973).Google Scholar
  11. [11]
    G. C. Sih, Application of Strain-Energy-Density Theory to Fundamental Fracture Problems, Lehigh University technical report AFOSR-TR-73-1.Google Scholar

Copyright information

© Noordhoff International Publishing 1974

Authors and Affiliations

  • P. D. Ewing
    • 1
  • J. G. Williams
    • 1
  1. 1.Mechanical Engineering DepartmentImperial College or Science and TechnologyLondonEngland

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