Modal validation of sandwich shell finite elements based on a p-order shear deformation theory including zigzag terms

• Published in: International journal for numerical methods in engineering 2008-09, Vol.75 (11), p.1301-1319
• Main Authors: Sulmoni, Mattia, Gmür, Thomas, Cugnoni, Joël, Matter, Marco
• Format: Article
• Language: English
• Subjects: composites; Computational techniques; Exact sciences and technology; finite element analysis; Fundamental areas of phenomenology (including applications); Mathematical methods in physics; modal analysis; Physics; sandwich structures; shell theory; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...)
• ISSN: 0029-5981; 1097-0207
• DOI: 10.1002/nme.2301

This paper describes a set of improved C0‐compatible composite shell finite elements for evaluating the global dynamic response (natural frequencies and mode shapes) of sandwich structures. Combining a through‐the‐thickness displacement approximation of variable high order with a first‐order zigzag function, the proposed finite elements are suited for modelling sandwich plates and doubly curved shells with a non‐uniform thickness and are more accurate than conventional models based on the first‐ and third‐order shear deformation theories, especially in sandwich panels with highly heterogeneous properties. The new finite element model is then validated by a comparison with the standard shell and 3D solid models. From these investigations, it can be concluded that adding a zigzag function even to high‐order polynomial approximations of the through‐the‐thickness displacement is a useful tool for refining the modelling of sandwich structures. In addition, the proposed formulation is sufficiently versatile to represent with the same level of accuracy the behaviour of thin‐to‐thick laminated shells as well as of strongly heterogeneous sandwich structures. Copyright © 2008 John Wiley & Sons, Ltd.