Formulation of a Nonlinear, Compatible Finite Element for the Analysis of Laminated Composites.
Abstract
Increased use of laminated composites has pointed out the need for better analytic tools. These tools must be able to correctly account for normal shear in the laminates and should be able to solve nonlinear problems. The finite element method can be applied to analyze laminated composites, and this research presents a new and unique method to include nonlinear effects and normal shear effects. The finite element is formulated from basic elasticity equations. The most unique characteristic of the element is the manner in which normal shear is handled. The normal to a reference surface is allowed to not only rotate but also to change shape. Not only is displacement continuity imposed at lamina interfaces, but also slope continuity is guaranteed. After a complete general formulation of the finite element is presented, the method is specialized to plates so that the convergence characteristics, the accuracy, and the applicability of the element can be studied. The finite element does an excellent job of analyzing laminated composites, although there is some degradation in accuracy as the plates become thinner. This finite element gives the analyst the ability to do nonlinear analysis of laminated composites under a variety of loading and boundary conditions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1982
- Accession Number
- ADA135997
Entities
People
- W. P. Witt Iii
Organizations
- Air Force Institute of Technology