Tese: Toughness Evaluation and Fracture Predictions in Elastoplastic Materials
Aluno(a) : Eduardo Enes CotaOrientador(a): Jaime Tupiassú
Área de Concentração: Mecânica Aplicada
Data: 21/02/2019
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.49793
Resumo: Understanding how to analyze crack-like defects is essential for many industries to avoid potentially catastrophic accidents. It is well known that structural Integrity standards use conservative procedures to evaluate the safety of cracked plate-like components like pipes and pressure vessels. To quantify how conservative such procedures are, critical loads predictions were computed on plate-like specimens of API 5L X80 steel (a high strength low alloy (HSLA) dual-phase steel developed for deep water pipelines) with a though wall crack. The specimens toughness was predicted by level 2 and 3 assessment procedures of the fitness-for-service standard API 579, and then compared with the actual loads needed to induce ductile tearing in them. The fracture toughness of the steel was measured through standard JIc and J-R resistance curve tests, using the elastic compliance technique with unloading/reloading sequences during the tearing process. Additionally, the geometry and type of loading effects, which can significantly change the value of the toughness, were analyzed using Elastoplastic Fracture Mechanics concepts. To do so, SE(B) specimens, which have high plastic transversal constraint, were tested following ASTM E1820-17 procedures. Then, their actual toughness were compared with literature procedures to estimate the toughness of SE(T) specimens, which have low plastic constraint, and with the actually measured date.