Failure Analysis of a Sleeper Anchor Model Used in Brazilian Railroads

Diego Antônio de Souza Santos¹; Geraldo Lúcio de Faria¹; Leonardo Barbosa Godefroid¹; Luiz Cláudio Cândido¹

¹ Universidade Federal de Ouro Preto

doi:10.20906/CPS/COB-2015-0885

Resumo

The sleeper anchors are important elements in railroads. They are buried into the ballast, and as the name suggest, they have an anchor function, contributing to the railroads fixation and increasing the railway stiffness. A Brazilian sleeper anchor has been used for many years by many Brazilian companies from the transport business. However, with the increasing of load per train wheel since last years, this model of sleeper anchor have been failing, avoiding the undesired ballast movement and creating a dangerous situation, with imminent risk of accidents. In this context, this work presents a complete failure analysis of this Brazilian sleeper anchor. Chemical, macro and microstructural analysis were done, as well mechanical tests in representative samples of sleeper anchor that have been failing recurrently in Brazilian railroads. An European model, aiming to compare their metallurgical characteristics, were also characterized. The obtained results showed that the studied failure is associated to an overload in Brazilian sleeper anchor. This overload promotes an undesirable plastic strain and the anchor is removed from the ballast. It was possible to conclude that the mechanical properties of Brazilian components do not attend the specifications for the actual load demand in national railways. It was also possible to observe that European sleeper anchors have better metallurgical characteristics than Brazilian one, for this application.

Palavras-chave: Railroads; Sleeper Anchor; Failure Analysis