A free-formulation-based flat shell element for non-linear analysis of thin composite structures

✍ Scribed by E. Madenci; A. Barut

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 791 KB
• Volume: 37
• Category: Article
• ISSN: 0029-5981
• DOI: 10.1002/nme.1620372206

✦ Synopsis

A flat shell element based on the free-formulation finite element concept is developed for analysing geometrically non-linear thin composite shells. A corotational form of the updated Lagrangian formulation is utilized. Numerical results for typical validation problems are presented in order to demonstrate the accuracy and validity of this element. These results are obtained by solving the incremental equilibrium equations through the cylindrical arc-length method. 'shear locking'. However, this may introduce spurious zero-energy modes. Recently, Kebari and Cassell' developed a degenerate shell element with a method to stabilize the spurious zero-energy modes. This element is capable of handling geometric and material non-linearities for isotropic materials. For the analysis of geometrically non-linear laminated composite shells, Yeom and Lee2 developed a degenerate solid shell element by assuming independent strain and displacement fields.

Although the initial developments with triangular flat shell elements suffered from convergence and poor performance on highly coupled bending and membrane deformations, Bathe and Ho3

and Hsiao4 eliminated these obstacles. Hsiao4 extended the flat shell element developed by Bathe and Ho3 by introducing a procedure to eliminate the restrictions of small rotations between two successive increments as part of the updated Lagrangian description of motion. This improvement permits the determination of large displacement and rotation increments for geometrically