Development of reliable modeling methodologies for engine fan blade out containment analysis. Part II: Finite element analysis

In the first part of the paper [Naik D, Sankaran S, Mobasher B, Rajan SD, Pereira M. Development of reliable modeling methodologies for fan blade-out containment analysis. Part I: experimental studies. Int J Impact Eng, in press], details of the experiments to characterize the behavior of dry fabrics including Kevlar ®49, and ballistic tests involving the fabric were presented. In this second part of the paper, we discuss the development and verification of a constitutive model for dry fabrics for use in an explicit finite element program. The developed constitutive model is implemented as a user-defined subroutine in LS-DYNA, a commercial finite element program. It is then used to simulate a suite of ballistic tests [Naik D, Sankaran S, Mobasher B, Rajan SD, Pereira M. Development of reliable modeling methodologies for fan blade-out containment analysis. Part I: experimental studies. Int J Impact Eng, in press] that replicate conditions seen in an engine fan blade out (FBO) event. A qualitative and quantitative comparison of the deformation shape of the fabric containment system and a quantitative comparison of the absorbed energy are carried out. Results indicate that the developed constitutive model provides a very encouraging start in modeling these high-speed events and could provide as Federal Aviation Administration (FAA) desires, an attractive complement to full-scale engine FBO tests.