The design and structural applications of urethane-cored sandwich panels

1966 ◽  
pp. 267-276 ◽  
Author(s):  
B.H. Fisher
Keyword(s):  
Sandwich Panels ◽  
Structural Applications

Effective Mechanical Behavior of Sandwich Beams under Uncoupled Bending and Torsion Loadings

2014 ◽  
Vol 590 ◽  
pp. 58-62 ◽  
Author(s):  
Hugo Miguel Silva ◽  
José Filipe Bizarro de Meireles
Keyword(s):  
Mechanical Behavior ◽  
Design Optimization ◽  
Sandwich Panels ◽  
Sandwich Beams ◽  
Honeycomb Core ◽  
Low Intensity ◽  
Specific Stiffness ◽  
Low Weight ◽  
Structural Applications ◽  
Non Linear

Sandwich geometries, mainly panels and beams are widely used in several transportation industries, namely aerospace, aeronautic and automotive. Sandwich geometries are known for their advantages in structural applications: high specific stiffness, low weight, and possibility of design optimization prior to manufacturing. This study aims to know the influence of the number of reinforcements (ribs), and of the thickness on the mechanical behavior of sandwich panels subjected to bending and torsion loads separately. In this study, 3 geometries are compared: simple web-core beam, corrugated core, and honeycomb core. The last 2 are asymmetric, due to the use of odd number of ribs. The influence of the geometry on the results is discussed, by means of a parameter that establishes a relation between the stiffness behavior and the mass of the object. It is shown that the all relations are non-linear, despite the elastic nature of the analysis, by means of the application of loads with low intensity.

scholarly journals Thermal Resistance of Insulated Precast Concrete Sandwich Panels

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Sani Mohammed Bida ◽  
Farah Nora Aznieta Abdul Aziz ◽  
Mohd Saleh Jaafar ◽  
Farzad Hejazi ◽  
Nabilah Abu Bakar
Keyword(s):  
Thermal Resistance ◽  
Alternative Energy ◽  
Precast Concrete ◽  
Sandwich Panels ◽  
Green Building ◽  
Control Panel ◽  
Shear Connectors ◽  
Shear Connection ◽  
Concrete Layer ◽  
Structural Applications

AbstractMany nations are already working toward full implementation of energy efficiency in buildings known as Green Building. In line with this perspective, this paper aims to develop a thermally efficient precast concrete sandwich panels (PCSP) for structural applications. Therefore, an experimental investigation was carried out to determine the thermal resistance of the proposed PCSP using Hotbox method and the results were validated using finite element method (FEM) in COMSOL Multiphysics Software. The PCSP were designed with staggered shear connectors to avoid thermal bridges between the successive layers. The staggered connectors are spaced at 200 mm, 300 mm and 400 mm on each concrete layer, while the control panel is designed with 200 mm direct shear connection. In the experimental test, four (4) panels of 500 mm × 500 mm and 150 mm thick were subjected to Hotbox Test to determine the thermal resistance. The result shows that thermal resistance of the PCSP with staggered shear connection increases with increase in spacing. The PCSP with 400 mm staggered shear connectors indicates the best thermal efficiency with a thermal resistance (R value) of 2.48 m2K/W. The thermal performance was verified by FEA which shows less than 5% error coupled with a precise prediction of surface temperature gradient. This indicates that, with conventional materials, thermal path approach can be used to develop a precast concrete building with better thermal resistant properties. Hopefully, stakeholders in the green building industry would find this proposed PCSP as an alternative energy efficient load bearing panel towards sustainable and greener buildings.

Impact/Debonding Tolerant Sandwich Panel With Aluminum Tube Reinforced Foam Core

2011 ◽  
Author(s):  
Gefu Ji ◽  
Zhenyu Ouyang ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Load Capacity ◽  
Sandwich Panels ◽  
Interface Debonding ◽  
Type I ◽  
Foam Core ◽  
Type Ii ◽  
Polymer Resin ◽  
The Core ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of hollow metallic microtubes reinforced polymer matrix. The objective of this study was to characterize its static and dynamic performances. Two types of new hybrid cores were investigated in this work. One consisted of polymer resin reinforced by transversely aligned continuous metallic militubes, denoted as type-I sandwich panel. The other was made of polymer resin reinforced by aligned continuous in-plane metallic militubes, denoted as type-II sandwich panel. Additionally, the traditional sandwich panels with polymeric syntactic foam core were also prepared for comparisons. Static and impact tests demonstrated that interface debonding and subsequent shear failure in the core could be largely excluded from the type-II panel. Meanwhile, a significant transition to ductile failure was observed in type-II sandwich panel with dramatically enhanced load capacity and impact energy dissipation. The results indicated that type-II panel may be considered a promising option for critical structural applications featured by debonding and impact tolerance.

Novel Impact/Debonding Tolerant Sandwich Panel With Millitubes Grid Stiffened Foam Core

2012 ◽  
Author(s):  
Guoqiang Li ◽  
Gefu Ji ◽  
Su-Seng Pang
Keyword(s):  
Sandwich Panel ◽  
Structural Integrity ◽  
Safety Concern ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Low Velocity ◽  
The Core ◽  
Sandwich Construction ◽  
Structural Applications

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new foam core is proposed which is a hybrid core consisting of grid stiffened hollow metallic millitubes reinforced polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of polymer resin reinforced by grid stiffened continuous metallic millitubes. Low velocity impact test demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

Shape Memory Polymer With Aluminum Tube Reinforced Impact Resistant Sandwich Core

2012 ◽  
Author(s):  
Gefu Ji ◽  
Guoqiang Li ◽  
Su-Seng Pang
Keyword(s):  
Shape Memory ◽  
Structural Integrity ◽  
Safety Concern ◽  
Shape Memory Polymer ◽  
Sandwich Panels ◽  
Low Velocity ◽  
The Core ◽  
Sandwich Construction ◽  
Structural Applications ◽  
Sandwich Core

Sandwich construction has been extensively used in various fields. However, sandwich panels have not been fully exploited in critical structural applications due to damage tolerance and safety concern. A major problem of sandwich panels is the debonding at or near the core/face sheet interface, especially under impact loading, which can lead to a sudden loss of structural integrity and cause catastrophic consequences. In order to improve the debonding resistance and energy absorption of sandwich panel under impact loadings, a new sandwich core is proposed which is a hybrid core consisting of hollow metallic millitubes reinforced Shape Memory Polymer matrix. The objective of this study was to characterize its dynamic performances. The core consisted of programmed shape memory polymer resin. Low velocity (4m/s) impact tests demonstrated that new core panel may be considered a promising option for critical structural applications featured by debonding and multiple impact tolerance.

Effective Design Analysis of Fixture Development for Stitching a Sandwich Panels in an Aerospace Application

2014 ◽  
Vol 592-594 ◽  
pp. 1055-1059 ◽  
Author(s):  
R. Santhanakrishnan ◽  
Darius Stanley ◽  
Thangavel Sanjeeviraja ◽  
A. Joseph Stanley
Keyword(s):  
Composite Structures ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Shear Stiffness ◽  
Foam Structure ◽  
Aerospace Application ◽  
Low Weight ◽  
Structural Applications ◽  
The Face ◽  
Effective Design

In recent years, sandwich structures have been considered as viable engineering constructions. The use of composite structures in aerospace and civil structural applications have been increasing especially due to their extremely low weight that leads to reduction in the total weight , high flexural and corrosion resistance in addition to higher transverse shear stiffness. Various combinations of core and face sheet thickness have been evaluated by many researchers worldwide. This study evaluates the aspects of putting the face sheets and core together through stitching and studies the effects and effectiveness of stitching. This paper mainly deals with design of fixture used to stitching sandwich panels, which helps to stitch different file orientations such as 900, 450, 900/450/900and 900/450. Keywords: Sandwich Panels, Composite Materials, Design of Fixture, Stitching panels, and Stitched Foam Structure

Effective Stiffness Behaviour of Sandwich Beams under Uncoupled Bending and Torsion Loadings

2016 ◽  
Vol 852 ◽  
pp. 469-475 ◽  
Author(s):  
Hugo Miguel Silva ◽  
José Filipe Meireles
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
Design Optimization ◽  
Sandwich Panels ◽  
Effective Stiffness ◽  
Sandwich Beams ◽  
Finite Element Software ◽  
Specific Stiffness ◽  
Low Weight ◽  
Structural Applications

Sandwich geometries, mainly in the form of panels and beams, are commonly applied in various transportation industries, such as aerospace, aeronautic and automotive. Sandwich geometries represent important advantages in structural applications, namely high specific stiffness, low weight, and possibility of design optimization prior to manufacturing. The aim of this paper is to uncover the influence of the number of reinforcements (ribs), and of the thickness on the mechanical behavior of all-metal sandwich panels subjected to uncoupled bending and torsion loadings. In this study, four geometries are compared. The orientation of the reinforcements and the effect of transversal ribs are also considered in this study. It is shown that the all the relations are non-linear, despite the elastic nature of the analysis in the Finite Element software ANSYS MECHANICAL APDL.

GFRP sandwich panels with PU foam and PP honeycomb cores for civil engineering structural applications

2012 ◽  
Vol 3 (2) ◽  
pp. 127-147 ◽  
Author(s):  
J.R. Correia ◽  
M. Garrido ◽  
J.A. Gonilha ◽  
F.A. Branco ◽  
L.G. Reis
Keyword(s):  
Civil Engineering ◽  
Sandwich Panels ◽  
Pu Foam ◽  
Structural Applications ◽  
Honeycomb Cores

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

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