• Cousigné, Olivier
• Coutellier, Daniel
• Naceur, Hakim
• Camanho, Pp
• Hampel, Steffen
• Moncayo, David

Abstract

International audience ; Due to their draping, stiffness, improved ductility and damage tolerance properties woven composites are being increasingly used for the construction of crash-relevant structural parts. Textile composites may depict a nonlinear behavior along several directions. Moreover, considerably-thick composite structures are likely to be used in order to increase energy absorption and to comply with the crash validation criteria. Therefore, a nonlinear numerical material model for textile composite materials has been developed for shells and thick shells. The model has been implemented as a user-defined subroutine (UMAT) in the LS-DYNA finite element code featuring with explicit time integration. The nonlinear behavior until failure is modeled in each in-plane material direction by a user-defined load curve or the Ramberg–Osgood equation. A plasticity formulation coupled with the nonlinearity accounts for permanent deformations. The failure is predicted using either a maximal stress criterion or the quadratic Tsai–Wu criterion. In order to model damage propagation, different post-failure damage definitions have been developed and implemented for each main in-plane material direction. A smeared formulation ensures the mesh independence in the presence of strain localization. The model has been assessed using characterization tensile and compressive tests on plain-weave and twill-weave carbon fiber composites.

Topics

• impedance spectroscopy
• Carbon
• composite
• plasticity
• ductility
• laser sintering
• woven