Abstract
Experiments are reported on spherical PMMA domes with thickness variations. The results were correlated with the parameter a 2/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.
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 α 2/RE où E 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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Ewing, P.D., Williams, J.G. The fracture of spherical shells under pressure and circular tubes with angled cracks in torsion. Int J Fract 10, 537–544 (1974). https://doi.org/10.1007/BF00155256
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DOI: https://doi.org/10.1007/BF00155256