Critical time step for a bilinear laminated composite Mindlin shell element.

Hammerand, Daniel Carl

Sandia National Laboratories

关键词: 36 Materials Science;    Laminated Materials-Mechanical Properties-Mathematical Models.;    Composite Materials;    Eigenvalues;    Finite Element Method;   

DOI  :  10.2172/919205
RP-ID  :  SAND2004-2487
RP-ID  :  AC04-94AL85000
RP-ID  :  919205

美国|英语

来源: UNT Digital Library

【 摘 要 】

The critical time step needed for explicit time integration of laminated shell finite element models is presented. Each layer is restricted to be orthotropic when viewed from a properly oriented material coordinate system. Mindlin shell theory is used in determining the laminated response that includes the effects of transverse shear. The effects of the membrane-bending coupling matrix from the laminate material model are included. Such a coupling matrix arises even in the case of non-symmetric lay-ups of differing isotropic layers. Single point integration is assumed to be used in determining a uniform strain response from the element. Using a technique based upon one from the literature, reduced eigenvalue problems are established to determine the remaining non-zero frequencies. It is shown that the eigenvalue problem arising from the inplane normal and shear stresses is decoupled from that arising from the transverse shear stresses. A verification example is presented where the exact and approximate results are compared.