Sandwich panel

About: Sandwich panel is a research topic. Over the lifetime, 4665 publications have been published within this topic receiving 49812 citations.

Effect of Soft Honeycomb Core on Flexural Vibration of Sandwich Panel using Low Order and High Order Shear Deformation Models

Abstract: Low order and high order shear deformation models are applied to investigate the effect of honeycomb core (transversely shear deformable) on flexural vibration of thick rectangular sandwich panel w...

Design and modelling of auxetic double arrowhead honeycomb core sandwich panels for performance improvement under air blast loading

Abstract: In the present study, a 2D-based large-scale metallic auxetic double arrowhead honeycomb core sandwich panel (DAHSP) was proposed and its deformation response, energy dissipation characteristics an

Impact Damage Tolerance of Graphite/Epoxy Sandwich Panels.

Abstract: The resistance of graphite/epoxy sandwich panels to low energy, foreign object impact damage was studied. Falling weight impact tests were performed on 104 rectangular sandwich panel specimens. The effect of several material, geometry, and loading parameters on damage susceptibility was explored. Damage observed visually was related to residual strength of specimens taken from the impact region, and in some cases, to static indentation tests carried out on companion specimens. Sandwich test specimens were fabricated with face sheets of graphite or S-glass/epoxy with a 1-in. depth nomex honeycomb core. Fiber type, core density, and laminate orientation were fabrication variables. Drop weight tests were accomplished using a 2-in.-diameter steel ball. Initial and residual static shear strength were measured on notched, four-point bend specimens. Impact tests showed that graphite sandwich panels are much more susceptible to foreign object damage than S-glass panels. The impact energy required to sustain the same relative damage level was an order of magnitude greater for the S-glass than for the graphite panels. The failure characteristics observed suggest that this is due primarily to the low strain to failure of graphite composites. Local core crushing occurred in all tests, and all but the S-glass panels suffered fiber fracture and permanent indentation at low energy levels. Core stiffness had an observable effect on impact resistance, but other parameters studied did not appear to significantly affect damage tolerance. An analysis was carried out in which the sandwich panel was represented as an orthotropic sheet on an elastic foundation, and a classical, double Fourier series approach was taken. The load condition was approximated by an influence function technique to effect a constant radius of bending curvature, simulating the region around the drop weight ball. The capability exists to vary the material constants of the face sheet and core to investigate the nature of indentation failure, and to identify factors contributing to impact resistance. Numerical results were obtained for some of the material parameters employed in the impact tests.

Thermal investigation of thin precast concrete sandwich panels

Abstract: Thin, lightweight alternatives to standard precast concrete sandwich panels have received much research and design focus in recent years. Some designs have been structurally tested and validated. Much less focus has, however, been given to their thermal performance. This study thermally investigates thin, lightweight precast concrete sandwich cladding panels that embed high performance insulation between two thin concrete wythes. A sample thin design is experimentally tested using a hot plate apparatus to evaluate its thermal performance. Finite element modelling is then used to further investigate the common features of thin panel designs and potential areas of heat loss. The analysed representative thin sample sandwich panel (150 mm thick) achieves an average U-value of 0.324 W m −2 K−1 ; this is 16% lower than that of a typical 315 mm thick sandwich panel with 100 mm of polystyrene foam insulation. Thermal bridging is identified as a major source of heat loss in the thin wall design, accounting for up to 71% of the total thermal transmittance of the tested thin sandwich panel. In standard walls this is usually less than 20%. Some of the features of the tested design can be improved to significantly reduce the effect of the thermal bridging and reduce the U-value by 59% to 0.13 W m −2 K−1 in an optimised panel design.

Sound transmission loss of composite and sandwich panels in thermal environment

Abstract: Composite sandwich structures are extensively applied in automotive, marine, aircraft because of superior stiffness-to-weight ratios. These structures are invariably exposed to the thermal and noise environment in their service life especially as a component of the hypersonic aircraft. The paper is originally focused on the sound transmission loss (STL) of the sandwich panels constituted of orthotropic materials in thermal environment. Firstly, the governing equations are obtained by applying Hamilton's principle. Both the natural frequencies and corresponding mode functions are derived with thermal stresses taking into account. The formulation of STL is obtained by using the mode superposition method. Then the published experimental result and numerical simulation are demonstrated to validate the accuracy of the analytical solution. Finally, the influences of temperature, elevation angle and azimuth angle of incident sound on the STL of finite sandwich panels are investigated systematically. It is observed that natural frequencies of the panel decrease and peaks of the STL tend to drop and flow to the lower frequencies with the increment of the temperature. The STL decreases with the increment of the elevation angle.