SommarioVengono esposti i risultati di una indagine teorica e sperimentale tendente a caratterizzare il comportamento meccanico e la resistenza a frattura di una trave fessurata a sezione circolare. Sebbene tali risultati non siano estrapolabili a geometrie più complesse, essi possono tuttavia risultare utili nella pratica, poichè la geometria circolare ricorre sia nel campo strutturale meccanico (alberi) che in quello civile (colonne, pilastri).Il problema teorico viene risolto numericamente, utilizzando un modello discreto con elementi resistenti in serie e in parallelo, come usualmente si fa in elettrodinamica. Nella parte terminale dell'articolo, infine, i risultati di esperienze condotte su travi fessurate di PMMA (plexiglass) a sezione quadrata e circolare sono descritti e discussi alla luce del modello assunto.SummaryIn the present paper, the results of a theoretical and experimental analysis are expounded, with the aim of characterizing the mechanical behaviour and the fracture resistance of a cracked beam with circular cross-section. Even if such results cannot be extrapolated to more complicated geometries, they can be of considerable practical importance, since the circular geometry recurs in the mechanical structural field (shafts) as well as in the civil one (pilasters, bearing piles). The theoretical problems is herein numerically solved, utilizing a discrete model with series and parallel resistant elements, as is usually made in electrodynamics. The results of tests carried out on cracked beams of PMMA with square and circular cross-sections are eventually shown and explained in the light of the assumed model.
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