Analysis and design of structural sandwich panels

Ogorkiewicz, R.M.

doi:10.1016/0010-4361(70)90244-2

Cited by 17 publications

(10 citation statements)

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“…ASTM C393 indicates that the results must be reported through the load versus crosshead displacement plots to determine if there is any significant compliance change (change in slope of the force-displacement curve, sometimes referred to as a transition region) before ultimate failure. However, for non-standard configurations, it is suggested that the width should not be less than twice the total thickness nor more than six times the total thickness [23,24]. The bending tests were performed in a universal testing machine MTS Insight with a cell load of 30 kN at room temperature and a crosshead speed of 0.5 mm/min.…”

Section: Methodsmentioning

confidence: 99%

Innovation in Aircraft Cabin Interior Panels. Part II: Technical Assessment on Replacing Glass Fiber with Thermoplastic Polymers and Panels Fabricated Using Vacuum Forming Process

et al. 2021

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The manufacturing process of the aircraft cabin interior panels is expensive and time-consuming, and the resulting panel requires rework due to damages that occurred during their fabrication. The aircraft interior panels must meet structural requirements; hence sandwich composites of a honeycomb core covered with two layers of pre-impregnated fiberglass skin are used. Flat sandwich composites are transformed into panels with complex shapes or geometries using the compression molding process, leading to advanced manufacturing challenges. Some aircraft interior panels are required for non-structural applications; hence sandwich composites can be substituted by cheaper alternative materials and transformed using disruptive manufacturing techniques. This paper evaluates the feasibility of replacing the honeycomb and fiberglass skin layers core with rigid polyurethane foams and thermoplastic polymers. The results show that the structural composites have higher mechanical performances than the proposed sandwich composites, but they are compatible with non-structural applications. Sandwich composite fabrication using the vacuum forming process is feasible for developing non-structural panels. This manufacturing technique is fast, easy, economical, and ecological as it uses recyclable materials. The vacuum forming also covers the entire panel, thus eliminating tapestries, paints, or finishes to the aircraft interior panels. The conclusion of the article describes the focus of future research.

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Section: Methodsmentioning

confidence: 99%

Innovation in Aircraft Cabin Interior Panels. Part II: Technical Assessment on Replacing Glass Fiber with Thermoplastic Polymers and Panels Fabricated Using Vacuum Forming Process

et al. 2021

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“…Equation ( 1) suggests that λ is independent of the applied strain, depends only on the material properties of the surface layer and substrate. [39] The A can be expressed as Equation ( 2), ε 0 is the applied strain and ε c is the critical strain [2,41]…”

Section: Fabrication Of Oriented Wrinkles On Anisotropic Pda/semi-pdm...mentioning

confidence: 99%

Spontaneous Formation of Oriented Lateral Wrinkles Assisted by Shrinkage Controlled Cracking

Liu

Shan

Yang

et al. 2022

Adv Materials Inter

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tunable optical devices, [8][9] and as structured templates for surface arrays, [10][11] etc. Therefore, the fabrication of oriented wrinkles is of great importance.Wrinkling occurs to release the compressive stresses caused by the lateral stresses generated between the two layers of a rigid capping layer/soft substrate. [12][13] The lateral stresses (e.g., thermal stresses) can induce changes in the surface morphology of common bilayer or multilayer composites (e.g., aluminum (Al)/poly dimethylsiloxane (PDMS), Al/polystyrene (PS)/silicon (Si)) which can be considered as infinite-planar 2D systems compared to the wavelength of the surface wrinkles. In such systems, surface wrinkles do not have any preferred orientation (i.e., disordered wrinkles), since the direction of the lateral stresses between the layers is on average, isotropic. However, when anisotropy of the lateral stresses between layers is introduced, the lateral stresses are first concentrated and accumulate in a certain region or along edges with topographic features, the detailed process being related to how anisotropy is introduced. When these accumulated lateral stresses are released anisotropically, making a change in the wrinkled orientation. [12][13][14] Therefore, the introduction of anisotropy of the lateral stresses is essential for the formation of oriented wrinkles.Currently, there are three main approaches to introduce the anisotropy of the lateral stresses for the generation of oriented wrinkles, one is to use patterned templates. [12,[15][16][17] Wang et al. prepared oriented wrinkles on a polydopamine (PDA)/PS bilayer film patterned with microgrooves by thermal annealing where the lateral stresses were preferentially concentrated and released at the edges of the groove patterns. [12] Qian et al. placed PDMS molds with striped relief structures as a confine on the PS/polyvinilpyrrolidone (PVP)/Si surface. The PVP layer subjected to water vapor changes to a viscous state, resulting in a mismatch in the Young's modulus of PS/PVP, when the diffusion forces accumulated along the edges of the mold are dedicated to releasing the compressive stress in a specified direction and the highly oriented wrinkles will be generated. [16] The second approach is by laser or plasma treatment. [13,[18][19][20] Okayasu et al. introduced a series of parallel striped cracks with different spacing dimensions on a silicon substrate through a standard photolithography process. During the heat treatment process, the lateral stresses perpendicular to the stripe direction could be anisotropically released in strain concentrations at the Oriented wrinkled surfaces play a vital role in the preparation of functional components. However, existing methods for the fabrication of oriented wrinkle patterns are often limited by specific equipment (e.g., high vacuum systems) and cumbersome processes. In this study, an approach utilizing shrinkage controlled cracking method is proposed to introduce prefabricated topographic patterns on flat semi-crosslinked polydimethylsiloxa...

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“…However, when combined, they form a solid cross-section which provides a significant increase in stiffness and strength compared with the individual constituents. In a sandwich panel, the external skins typically provide bending strength while the internal core carries shear forces and limits local wrinkling of the steel sheeting [2][3][4][5]. Sandwich panels with a polyurethane core have been widely used in the past.…”

Section: Introductionmentioning

confidence: 99%

Bending response of sandwich panels with steel skins and aluminium foam core

Latour

D’Aniello

Babcsán³

et al. 2022

Steel Construction

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Nominated for Eurosteel 2021 Best Paper Award The introduction to the market of metal foams represents a significant opportunity to increase the use of metal in the construction market. In fact, the development of new products made of metal foams and steel could improve the performance of conventional buildings in terms of stiffness and resistance. The first structural applications of these materials have already shown the potential of composites made of foam and steel, and demonstrated the feasibility of producing mono‐dimensional and bi‐dimensional elements with a high resistance‐to‐weight ratio. Reducing the structural weight can be a significant advantage in many cases, such as infrastructures or buildings in seismic zones. Within this framework, the work presented in this paper aims to assess the response of composite sandwich panels made of steel and aluminium foam using a set of tests that will serve as the basis for developing a new system of dry‐assembled composite floors. The tests were carried out at the Strength laboratory (Structural Engineering Test Hall) at the University of Salerno, Italy and were designed to verify the mechanical properties of metal foam panels and double‐skin glued sandwich panels. The tests have shed light on the basic mechanical properties of both foams and sandwich panels.

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Analysis and design of structural sandwich panels

Cited by 17 publications

References 0 publications

Innovation in Aircraft Cabin Interior Panels. Part II: Technical Assessment on Replacing Glass Fiber with Thermoplastic Polymers and Panels Fabricated Using Vacuum Forming Process

Innovation in Aircraft Cabin Interior Panels. Part II: Technical Assessment on Replacing Glass Fiber with Thermoplastic Polymers and Panels Fabricated Using Vacuum Forming Process

Spontaneous Formation of Oriented Lateral Wrinkles Assisted by Shrinkage Controlled Cracking

Bending response of sandwich panels with steel skins and aluminium foam core

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