Properties Of Sandwich Panels Research Articles

The properties of sandwich panels made of standard wood-based panels

The properties of sandwich panels made of standard wood-based panels. The properties of sandwich panels made of standard wood-based panels were examined. Particleboards, MDF and OSB panels as well as plywood were used as internal and external layers of panels. Two types of adhesives: PUR and PVA were used to bind the layers. The physical and mechanical properties of glued sandwich panels were investigated. It was found out that OSB panels covered with plywood have the highest MOE and MOR values, and the panels with an internal layer composed of MDF have the lowest of WA and TS. It has been shown that regardless of the materials used, a panel glued with PUR achieves higher mechanical properties and the lowest WA and TS values.

Graphene Effect on Mechanical Properties of Sandwich Panel for Aerospace Structures

This research examines the mechanical properties of graphene-based polymer composites and Nomex honeycomb sandwich using a new strain sensing technique. Sandwich panels are fabricated individually with glass fibre reinforced polymers (GFRP) and face-sheets having different filler ratios of graphene nanoparticles (GNPs). These graphene nanoparticles are oxidized with (UV-O3) ozone to get graphene oxide (GO) which in turn improves resin matrix interfacial strength. Filler ratios of GO 0.0%, 0.2%, 0.6% and 1.0% by weight of poly-epoxy are fabricated for the face-sheets of composite sandwich panels. Graphene-based strain sensors are synthesized having a concentration of GNPs 5% by weight of polystyrene (PS). The strain sensors are pasted on the sandwich panels and four-point bending of the sandwich beams is performed to predict its flexural strength. The response of composite under different filler ratios of graphene oxide on mechanical properties is inspected during mechanical testing of sandwich panels and the results of (PS-GNPs) strain sensors will be compared with the strains produced during mechanical testing.

Ultra high strength steel sandwich for lightweight applications

Methods for reducing weight of structural elements are important for a sustainable society. Over the recent years ultra high strength steel (UHSS) has been a successful material for designing light and strong components. Sandwich panels are interesting structural components to further explore areas where the benefits of UHSS can be utilized. The specific properties of sandwich panels make them suitable for stiffness applications and various cores have been studied extensively. In the present work, bidirectionally corrugated UHSS cores are studied experimentally and numerically. A UHSS core is manufactured by cold rolling and bonded to the skins by welding. Stiffness is evaluated experimentally in three-point bending. The tests are virtually reproduced using the finite element method. Precise discretization of the core requires large amounts of computational power, prolonging lead times for sandwich component development, which in the present work is addressed by homogenization, using an equivalent material formulation. Input data for the equivalent models is obtained by characterizing representative volume elements of the periodic cores under periodic boundary conditions. The homogenized panel reduces the number of finite elements and thus the computational time while maintaining accuracy. Numerical results are validated and agree well with experimental testing. Important findings from experimental and simulation results show that the suggested panels provide superior specific bending stiffness as compared to solid panels. This work shows that lightweight UHSS sandwiches with excellent stiffness properties can be manufactured and modeled efficiently. The concept of manufacturing a UHSS sandwich panel expands the usability of UHSS to new areas.

Size effect in the fracture properties of sandwich panels of plasterboard and core of rock wool

This paper extends the previous work of the authors and deals with the study of fracture of sandwich panels of plasterboard and rock wool under in-plane bending and tensile loading. It presents the results of the experimental campaign focused on the size effect of the tested specimens. To this end, mixed-mode (I and II) fracture tests have been carried out with specimens of three different sizes. The experimental results are compared with the values obtained from the numerical simulation of the test by using a model based on the embedded cohesive crack developed by the authors in previous published works. Comparison of the results shows how the model is able to reproduce the size effect of the specimens in this material from the parameters that characterize fracture behaviour. The aim is to use the cohesive model proposed by the authors to move from laboratory tests to a built panel.

A Study on Strength Properties of Sandwich Panels Including Flame Resisting Polyurethane Foam Cores for Application to Rolling Stocks

A Study on Strength Properties of Sandwich Panels Including Flame Resisting Polyurethane Foam Cores for Application to Rolling Stocks

Experimental-Theoretical Research of Mechanical Properties of Perforated Composite Sandwich Panels

This work is devoted to experimental-theoretical analysis of mechanical properties of sandwich panels made of fibrous polymer composite materials. The structures with tubular core were considered. Numerical simulations of the mechanical behaviour and tensile testing of full-scale samples of sandwich panels were done. The analysis of influence of perforation on mechanical properties of fiberglass laminates and sandwich panels was alsoperformed.

Mechanical Properties of Kenaf Core Sandwich Panel Toughened with Modified Epoxy

Kenaf-core sandwich panels were prepared by hand lay-up method with the optimum characteristics. The aim of this study is to determine the effects of modified epoxy on the mechanical properties of the sandwich panel. Mechanical test such as flexural, drop impact and tensile test were performed to investigate the optimum system of kenaf-core sandwich panel within 0-5wt% of kenaf fiber content. It revealed that the optimum loading of kenaf fiber was at 3wt%. Furthermore, this system was studied with the incorporation of liquid natural rubber (LNR) as impact modifier. All tests have been carried out according to the ASTM 365, C297, C393, and D1736. Each final data point is an average value that has been obtained based on a statistical sampling of four specimens. The main element of core structure is kenaf and the skin used in this study is aluminium type 1100. According to compression, flatwise tensile, three point bending and drop impact tests, 3wt% of LNR content exhibit as an excellent impact modifier, in modifying the mechanical properties due to rubber toughening. In addition of too much liquid natural rubber more than 5wt% was substantially interrupted the system.

Composite sandwich panel with multifunction of load bearing, heat insulation, and thermal protection

Integrative sandwich panels with multifunction of load bearing, thermal protection, and heat insulation are manufactured through co-injection resin transfer molding process. These panels have a polymethacrylimide foam core for heat insulation and two composite layers made of carbon/epoxy for load bearing and carbon/phenolic for thermal protection. In co-injection resin transfer molding process, the epoxy resin and phenolic resin are synchronously injected and cured in order to make integrative structures and improve the properties of the interface between different layers. The influence of main factors in the process of co-injection is investigated: the vacuum assistance is indispensable to improve the efficiency of manufacture and guarantee the properties of the products, volume fraction of carbon fiber plays the main role in determining size accuracy of the product, adjusting injection pressure is a simple and efficient way to adjust the infusion time of resin, while injection temperature has smaller influence in the features of manufacture. The mechanical properties of sandwich panels manufactured through co-injection resin transfer molding process and multi-step process are tested and compared to validate the advantage of the co-injection resin transfer molding process. The test shows that the in-plane compressive strength, three-point flexural strength, and interface shear strength are all improved by the co-injection resin transfer molding process. Co-injection resin transfer molding process is proved to be a feasible and efficient way to manufacture the integrative sandwich panel with good interface features.

Flexural Properties of Kenaf Sandwich Panel

This study concerns on effect of varying skin thickness to flexural properties of sandwich panel. The main element of the core structure is kenaf and the skin used in this study is galvanised steel sheet. Skin thickness being used in this research is 1.0 mm and 1.2 mm. In this study, comparing sandwich of skin thickness 1.0 mm and 1.2 mm, result shows that 1.0 mm skin is sufficient as mechanical properties of sandwich decreases and density of sandwich increases as skin thickens.