Minimum weight web-core sandwich panels subjected to uniaxial compression.

1971 ◽  
Vol 8 (11) ◽  
pp. 843-847 ◽  
Author(s):  
JACK R. VINSON ◽  
SIDNEY SHORE
Keyword(s):  
Uniaxial Compression ◽  
Minimum Weight ◽  
Sandwich Panels

Optimal design of sandwich panels with hybrid core

2017 ◽  
Vol 21 (7) ◽  
pp. 2181-2193 ◽  
Author(s):  
Robert Studziński
Keyword(s):  
Sandwich Panel ◽  
Minimum Weight ◽  
Sandwich Panels ◽  
Inequality Constraints ◽  
Optimization Procedure ◽  
Geometrical Parameters ◽  
Optimal Solutions ◽  
Limit States ◽  
Mathematical Functions ◽  
Flat Steel

The main aim of the paper is to find optimal solutions of sandwich panels with flat steel facings and a hybrid core made of aerogel and polyisocyanurate (PIR) foam. The optimal solutions have to satisfy conflicting criteria, i.e. a maximum range of applications and minimum weight, while at the same time respecting both the principles of sustainable development in the construction industry and the limit states (ultimate and serviceability) conditions. The design vector consists of the geometrical parameters of the sandwich panel including its span length and the parameter which describes the proportion of aerogel thickness to the total thickness of the core. The mechanical properties of the hybrid core are described by mathematical functions which were obtained in laboratory tests. In optimization, an evolutionary algorithm was used. The Pareto results were obtained while respecting the inequality constraints introduced in the optimization procedure directly (box conditions) and by means of the external penalty function. The presented optimization of a sandwich panel extends the class of problems discussed in the literature by considering both the hybrid core and the thermal conductivity aspect.

scholarly journals Synergistic effects of halloysite nanotubes with metal and phosphorus additives on the optimal design of eco-friendly sandwich panels with maximum flame resistance and minimum weight

2021 ◽  
Vol 11 (1) ◽  
pp. 252-265
Author(s):  
Saeed Kamarian ◽  
Ruiwen Yu ◽  
Jung-il Song
Keyword(s):  
Optimal Design ◽  
Failure Modes ◽  
Sandwich Structures ◽  
Synergistic Effects ◽  
Minimum Weight ◽  
Computational Cost ◽  
Sandwich Panels ◽  
Halloysite Nanotubes ◽  
Flame Resistance ◽  
Cone Calorimeter Test

Abstract The present work addresses the optimal design of sandwich panels made of flax fabric (FF)/vinyl ester (VE) composite face sheets and honeycomb VE core. The sandwich structures are first optimized in terms of flammability by obtaining the best combination of ammonium polyphosphate (APP), halloysite nanotube (HNT), and magnesium hydroxide (MH) as three flame retardants (FRs). Using the Taguchi method and horizontal burning test, it is shown that [6, 3, and 3%] and [1, 0.5, and 0%] are the optimal combinations of APP, HNT, and MH for the face sheets and core, respectively. Cone calorimeter test results indicate that the optimal FR combinations significantly decrease the mass lost rate (MLR), heat rate release (HRR), total smoke release (TSR), and maximum average release heat emission (MARHE). The FR sandwich structures are then geometrically optimized under compressive loads based on their weight. Different failure modes are considered as the design constraints of the optimization problem. Imperialist competitive algorithm (ICA), as a powerful meta-heuristic algorithm, is implemented to considerably reduce the computational cost of the optimization process. The results of this study show that proper combinations of FR additives can increase the flame retardancy while decreasing the weight of sandwich panels.

Wrinkling of Functionally Graded Sandwich Structures Subject to Biaxial and In-Plane Shear Loads

2017 ◽  
Vol 84 (12) ◽  
Author(s):  
Victor Birman ◽  
Harold Costa
Keyword(s):  
Uniaxial Compression ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Shear Loading ◽  
Functionally Graded ◽  
Biaxial Compression ◽  
Equal Weight ◽  
Plane Shear ◽  
The Core ◽  
Shear Loads

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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