Best theory diagrams for multilayered structures via shell finite elements

Abstract

Composite structures are convenient structural solutions for many engineering fields, but their design is challenging and may lead to oversizing due to the significant amount of uncertainties concerning the current modeling capabilities. From a structural analysis standpoint, the finite element method is the most used approach and shell elements are of primary importance in the case of thin structures. Current research efforts aim at improving the accuracy of such elements with limited computational overheads to improve the predictive capabilities and widen the applicability to complex structures and nonlinear cases. The present paper presents shell elements with the minimum number of nodal degrees of freedom and maximum accuracy. Such elements compose the best theory diagram stemming from the combined use of the Carrera Unified Formulation and the Axiomatic/Asymptotic Method. Moreover, this paper provides guidelines on the choice of the proper higher-order terms via the introduction of relevance factor diagrams. The numerical cases consider various sets of design parameters such as the thickness, curvature, stacking sequence, and boundary conditions. The results show that the most relevant set of higher-order terms are third-order and that the thickness plays the primary role in their choice. Moreover, certain terms have very high influence, and their neglect may affect the accuracy of the model significantly.

Experimental study of elastic-plastic deformation of a cylindrical shell made of steel 45

“…Выяснилось, что в теории устойчивости за пределом упругости нарушение единственности процесса нагружения и потеря устойчивости могут не совпадать. За пределом упругости прежде всего нужно знать критические и закритические деформации и перемещения [9].…”

Third-Order Theory for the Bending Analysis of Laminated Thin and Thick Plates Including the Strain Gradient Effect

“…Consequently, there is no need for the shear correction factor [ 9 , 10 , 11 , 12 ]. The importance of these cubic terms in the analysis of laminates has been recently highlighted in the paper by Petrolo and Carrera [ 13 ], in which the best theory diagrams for multilayered structures have been widely discussed.…”