Análise mecânica da conformação de amostras dobradas em U usadas em teste de corrosão sob tensão

Abstract

The susceptibility to stress corrosion cracking can be evaluated in specimens produced according to the ASTM G30-97 (2016) standard, where an initially flat blank is formed to assume a U-shape. The stresses and strains were evaluated by simulation using the finite element method. The API 5L X70 steel test specimen underwent three forming phases: bending, elastic recovery, and screwing. The elastic recovery was analyzed by the opening distance and the stress. The friction between the specimen and the tool changed the stress state for the first two phases, but it was not influential after the final tightening by screw. The increase in this coefficient hindered the specimen from slipping on the tool, which provides more concentrated stress in the center of the convex region. For the simulated forming, the coefficient of friction virtually did not interfere in the specimens´ final stress state after tightening the screw.