The present work show the results obtained from the testing campaign on pure iridium at different temperatures (25÷1250 °C) and strain-rates (10-3÷104 s -1 ) in order to identify a strength material model. At low temperature, the material deforms uniformly up to fracture; at intermediate temperatures, it shows an early necking at low strain-rates while a marked hardening followed by necking at higher speed; over 1000 °C it shows an initial uniform elongation followed by necking. Due to the presence of recrystallization (between 750 e 1000°C), it was not possible to identify a unique material model, but the idea was to get two different Johnson-Cook models by means of a multi-objective optimization. The likelihood of the obtained parameters was validated through FE simulation of the different loading conditions. Post-mortem analyses of the fracture surface proved the presence of different failure mechanism.
MODELLAZIONE DEL COMPORTAMENTO MECCANICO DELL’IRIDIO PURO IN CONDIZIONI DI SOLLECITAZIONE DINAMICA / Scapin, Martina; Peroni, Lorenzo; Tridello, Andrea. - ELETTRONICO. - (2016), pp. 1-10. (Intervento presentato al convegno 45° CONVEGNO NAZIONALE AIAS tenutosi a Trieste nel 7-10 Settembre 2016).
MODELLAZIONE DEL COMPORTAMENTO MECCANICO DELL’IRIDIO PURO IN CONDIZIONI DI SOLLECITAZIONE DINAMICA
Scapin, Martina;PERONI, LORENZO;TRIDELLO, ANDREA
2016
Abstract
The present work show the results obtained from the testing campaign on pure iridium at different temperatures (25÷1250 °C) and strain-rates (10-3÷104 s -1 ) in order to identify a strength material model. At low temperature, the material deforms uniformly up to fracture; at intermediate temperatures, it shows an early necking at low strain-rates while a marked hardening followed by necking at higher speed; over 1000 °C it shows an initial uniform elongation followed by necking. Due to the presence of recrystallization (between 750 e 1000°C), it was not possible to identify a unique material model, but the idea was to get two different Johnson-Cook models by means of a multi-objective optimization. The likelihood of the obtained parameters was validated through FE simulation of the different loading conditions. Post-mortem analyses of the fracture surface proved the presence of different failure mechanism.Pubblicazioni consigliate
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https://hdl.handle.net/11583/2677127
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