Digital image correlation and infrared measurements to determine the influence of a uniaxial pre-strain on fatigue properties of a dual phase steel.

• Main Authors: Calloch S., Munier R., Doudard C., Weber B.
• Format: Article
• Language: English
• Published: EDP Sciences 2010-06-01
• Series: EPJ Web of Conferences
• Online Access: http://dx.doi.org/10.1051/epjconf/20100637007

The high cycle fatigue (HCF) is a major element for a great design of automotive parts. A wide part of the steel sheets for the automotive industry are stamped, sometimes deeply. During this operation, the steel is plastically strained in different directions, so that a good prediction of the fatigue behavior requires the determination of the fatigue properties of the pre-strained material. Nowadays, the evolution of HCF properties is often neglected, because of prohibitive time dedicated to traditional fatigue campaigns. To reduce the characterization time, self-heating measurements are used. This approach permits to identify the influence of homogeneous pre-strain on fatigue properties. The aim of this paper is to develop an original experimental test to identify this influence for a wide range of pre-strain with only one specimen. The study of a particular case of specimen with a constant gradient of pre-strain is presented. Digital image correlation is a way to determine the heterogeneity of the plastic pre-strain on the specimen and infrared measurements with a ”1D” approach allows the determination of the influence of a plastic pre-strain on the fatigue properties of the studied steel.