STRUCTURAL OPTIMIZATION OF CORRUGATED CORE AND WEB CORE SANDWICH PANELS SUBJECTED TO UNIAXIAL COMPRESSION

Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper (Birman, V., and Vo, N., 2017, “Wrinkling in Sandwich Structures With a Functionally Graded Core,” ASME J. Appl. Mech., 84(2), p. 021002), where a several-fold increase in the wrinkling stress was achieved, without a significant weight penalty, using a stiffer core adjacent to the facings. In this paper, wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading, and the core is arbitrary graded through the thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core, and the verification that functional grading of the core remains an effective tool increasing wrinkling stability under such two-dimensional (2D) loads. As follows from the study, biaxial compression and in-plane shear cause a reduction in the wrinkling stress compared to the case of a uniaxial compression in all grading scenarios. Accordingly, even sandwich panels whose mode of failure under uniaxial compression was global buckling, the loss of strength in the facings or core crimpling may become vulnerable to wrinkling under 2D in-plane loading. It is demonstrated that a functionally graded core with the material distributed to increase the local stiffness in the interface region with the facings is effective in preventing wrinkling under arbitrary in-plane loads compared to the equal weight homogeneous core.

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Design Optimization of Steel Sandwich Hoistable Car Decks Applying Homogenized Plate Theory

Journal of Ship Production ◽

10.5957/jsp.2008.24.2.108 ◽

2008 ◽

Vol 24 (02) ◽

pp. 108-115

Author(s):

Jani Romanoff ◽

Alan Klanac

Keyword(s):

Genetic Algorithm ◽

Structural Optimization ◽

Design Optimization ◽

Plate Theory ◽

Sandwich Panels ◽

Sandwich Plates ◽

Concept Design ◽

Bending Response

This paper describes an approach for concept design of laser-welded web-core steel sandwich panels. The method uses a newly developed theory for the bending response of laser-welded web-core sandwich plates. Structural optimization is carried out using enumeration and newly developed vectorization-based genetic algorithm. To demonstrate these concepts, a case study in design of a hoistable car deck is considered. Finally, the optimization is conducted considering the objectives of deck weight.

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