A multi-director finite element shell theory for composite laminates
- Univ. of Illinois, Chicago, IL (United States)
This paper presents a multi-layered, multi-director, shear deformable finite element shell theory for composite laminates. The displacement field is assumed continuous across the finite element layers through the composite thickness whereas the rotation field is layer-wise continuous with possible discontinuity across layers. This novel idea results in independent shear deformation of the director associated with each layer and thus allows the warping of the composite cross section. The resulting strain field is discontinuous across the different material sets (plies), thereby creating the provision that the interlaminar transverse stresses computed from ply-level constitutive relations can be continuous. Through-thickness deformation of composite laminates is incorporated in the formulation, thereby the theory captures the three dimensional features of composite laminates. In particular, the 3-D deformation of free edges and peeling stresses in these structures are predicted accurately. While the theory enjoys the accuracy of higher order theories, only first derivatives of displacement and rotation fields appear in the variational equations and the number of partial differential equations is independent of the number of plies and their orientation in the composite. The proposed theory presents a feasible numerical strategy for accurate analysis of highly anisotropic composite laminates. This paper is focused on the analysis of flat geometris. Free edge effects and interlaminates stresses around cutouts in laminates are presented, The results of analysis of curved geometries will be prorated in a follow-up paper.
- OSTI ID:
- 175459
- Report Number(s):
- CONF-950686--
- Country of Publication:
- United States
- Language:
- English
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